# Check out pics. Let me know what you think. 2010!



## cvjoint

I bought a different car after abusing my Accord for 6 years. I've been pondering the system from way before I bought it. I haven't bought any gear yet, well I have two Clarion amps but all is subject to change. Basically critique or support my choices just like you guys did in 2007!

Enter the S2000 (240hp, 2810lbs, RWD,50/50 Distrib.):


































Pillar (about 4 inches wide):

















Kick driver's side:









Doors:


----------



## cvjoint

Behind the driver's seat:









Tray behind the seats can come off, only there for sound deadening and looks:








It creates a clear path between trunk and cabin, about 13inchx37inch opening:








looking through from inside:









Trunk (Again opening is more or less 13 inches by 37):








Behind drivers -- the fuel tank:








Behind passenger the spare ( I will get rid off):


----------



## cvjoint

Approximate measurements:
Pillar:
12"Hx4"Wx1"D
Kick:
no room unless I loose dead pedal 
5"x5"x5"
behind the seat:
virtually no room, 10"x6" opening with no depth
Under soft top mechanism there is a 6"Hx37"Wx15" opening, but you must substract volume of the tank protrusion
Trunk size is 4.9 cubes with a tool box, 5.5 as you see it

My ideas:
I can fit 3 12" subs IB in that opening firing towards the trunk gate. The opening is 37"x13" so I'll have to overlap one sub to get a half inch or so width, no biggie. The AE IB12s would work great, and give .7 Q in a trunk that's 5.5ft3
Credit pionkej install thread (like this but three of them):









The doors can house most 7 inch speakers that are truncated or 6.5 inch speakers that are round.Depth is only 3 inches. I plan to use the B&C 6ndl44. 
Credit Parts Express:









Pillars can hold a BG Neo8 upright and a small format tweeter right above, I'm thinking Vifa xt25.
Credit Parts express:

















Xover frequencies:
20hz-100hz subs
100hz-1600hz woofers
1600hz-6000hz planar tweeter
6000hz-20000hz ring radiator tweeter

Every speaker chosen will then be at least 90db sensitive in it's operating band, and handle lots of power to boot. I'm hoping for 110db capability on each given the filters. 

Combined with three amps to drive them this will come under 100lbs, all weight will be between the two axles, trunk space will be left unchanged. Amps will be mounted between the subs and the seats in that cubicle below the softop. 

Let's say power is not an issue, cost is not an issue. I would like it to be low weight, and deliver lots of output. 

Priorities 
1. High output (I tested 70mph road noise at 78db A-weighted, 92db C-weighted)
2. Low distortion
3. Must not get in the way of driving
4. Must not weigh more than 100lbs 
5. Staging

Almost forgot headunit:
Pioneer Dex-P99rs or Carputer (might do the P99 for low noise and weight savings)


----------



## stereo_luver

Six 15's and a tweeter.....LOL

Seriously..have fun. Think.....Zuki amps. I know you have the Carion's but there is this thing called the classifieds.

Chuck


----------



## cvjoint

stereo_luver said:


> Six 15's and a tweeter.....LOL
> 
> Seriously..have fun. Think.....Zuki amps. I know you have the Carion's but there is this thing called the classifieds.
> 
> Chuck


Well amps are easy, no reason to go into it. I would not get the Zuki simply based on not having any information.


----------



## fish

Nice choices on drivers. Three 12's IB in that tiny car is gonna be crazy! This will be a fun one to watch.

FYI...
If you decide to go with the Clarion DPX's I have three of the 2251's BNIB.


----------



## goodstuff

Are you going to keep it yellow?


----------



## stills

baallin'
pretty big trunk for a vert. nice sized door openings too.
that's a heck of a car, audio aside.

i'd like to see more neo8. i hope it works out for you.


----------



## cvjoint

fish said:


> Nice choices on drivers. Three 12's IB in that tiny car is gonna be crazy! This will be a fun one to watch.
> 
> FYI...
> If you decide to go with the Clarion DPX's I have three of the 2251's BNIB.


John said three 12s have the same output as 2 15s. On thing to note is that even if I were able to fit 2 15s they require way more trunk space. 



goodstuff said:


> Are you going to keep it yellow?


Going with the black/yellow theme all throughout. The afterwarket wheels will be a charcoal/black. All the speakers are black haha and the amps will be hidden. 

Yellow was my #1 choice. There are some stigma effects with this color but it looks damn good, and contrasts the top very well. 



stills said:


> baallin'
> pretty big trunk for a vert. nice sized door openings too.
> that's a heck of a car, audio aside.
> 
> i'd like to see more neo8. i hope it works out for you.


I was in heaven when I found out there is such a big opening between the inside and the trunk, IB glory! Volume wise the Boxter has a beat with two trunks this size.


----------



## Rob J

I like your choice of transducers, but I'd cross the sub over a bit lower. I'd start at 80hz.


----------



## hybridspl

In for details! I just bought a 2004 Silverstone AP2 and plan on a lot of deadening first. I was considering horns but am concerned about the console and I like the route you are going.


----------



## cvjoint

Rob J said:


> I like your choice of transducers, but I'd cross the sub over a bit lower. I'd start at 80hz.


Ideally I'd want to cross at 60hz or so, that's what I did with 10s in the doors with the Accord. Unfortunately there is no way door speakers can deliver the punch in an S2000, there is no room. You have to either trade off low end extension (like I'm doing with the pro audio drivers) or trade off output (this will be the Peerless SLS way if it even fits) 

Besides I'm not convinced there is anything to lose by crossing over these subs at 100hz vs. 60hz. 



hybridspl said:


> In for details! I just bought a 2004 Silverstone AP2 and plan on a lot of deadening first. I was considering horns but am concerned about the console and I like the route you are going.


I've considered horns, I was particularly happy with their high output and lower crossover points. But...um just look at the dash for a sec. The driver one is like a foot taller! The dash is highly asymmetrical and the passenger under-dash is full of gear already. 

Proper horn bodies are preferably reinforced plastic or aluminum and together with the compression driver quite heavy for a tweeter. Not to mention your knees might hit them and obstruct them. I'm not saying it's an impossibility but those were my thoughts.


----------



## DaveRulz

No qualms with the chosen gear here. How do you plan to keep the handling characteristics with all that gear in the trunk? I'd imagine it's pretty likely your 50/50 weight balance is going to change without some clever balancing of where gear is installed. 

Just stick with the whizzer cones


----------



## jonnyanalog

DaveRulz said:


> No qualms with the chosen gear here. How do you plan to keep the handling characteristics with all that gear in the trunk? I'd imagine it's pretty likely your 50/50 weight balance is going to change without some clever balancing of where gear is installed.
> 
> Just stick with the whizzer cones


+1
There is no way I would sacrfice the balance of an S2000 has for audio. I would do 3 8s imo and accept the trade off.


----------



## Oliver

To bad this car is a drop top [sad face ]


----------



## DS-21

Interesting ideas. I kind of envy you being able to put real subs in I-B; my Miata has a pesky gas tank in the way.

Only comments are, have you heard the Neo8's? Honestly, I just don't care for them. And angled down, without lots of airspace behind them to control the backwave, IMO you're asking for trouble there. (BG's are _notoriously_ sensitive to reflections from the backwaves, because the diaphragm is so easy to move.) A 3" cone widebander would likely be a better choice. 

As for balance, people shouldn't be silly. A little extra mass behind the cabin within the wheelbase won't materially hurt anything. Especially since the S2000 is a fairly heavy car as it is. (Yes, 2800lbs is a heavy car to me!) At worst, distribution MIGHT go to 48/52. Which is fine.


----------



## cvjoint

DaveRulz said:


> No qualms with the chosen gear here. How do you plan to keep the handling characteristics with all that gear in the trunk? I'd imagine it's pretty likely your 50/50 weight balance is going to change without some clever balancing of where gear is installed.
> 
> Just stick with the whizzer cones


The spare and tool kit weighs 40lbs. Amplifiers +subs + lightweight mdf and connections: 35lbs+45lbs+5lbs+5lbs=90lbs. Make note these will all be on top or ahead of the rear axle. So we have a 50lbs increase on the rear axle. The front speaker upgrade will add on 10lbs and the the supercharger  will add the remaining 40lbs. This 50lbs increase on the front is also behind the front axle. 

Together, all modifications on this car will add 100lbs all between the two axles. The supercharger will more than overcome the weight differential by adding 80lb/ft of TQ. Tire sizes will increase from 205 front to 255/265 and from 225back to 295. 

Secondly the subwoofer baffle + amp rack will be removable. A total of 5 large hand tightened bolts will hold up the two pieces. Removal time will be under one minute given the quick disconnects I plan to use for track time. 

Up to 200lbs of weight can be shed off but with lots of money: Dry carbon doors, hood, trunk, fenders, bumpers, titanium header and exhaust. 



a$$hole said:


> To bad this car is a drop top [sad face ]


Or an aluminum hardtop or a carbon fiber hardtop. You choose from the myriad of parts available for this car. I'll keep it softtop. There is no replacement for open air motoring in the canyons or track. Honda put in lots of engineering to make it safe for rollovers and easy to manage.


----------



## cvjoint

DS-21 said:


> Interesting ideas. I kind of envy you being able to put real subs in I-B; my Miata has a pesky gas tank in the way.
> 
> Only comments are, have you heard the Neo8's? Honestly, I just don't care for them. And angled down, without lots of airspace behind them to control the backwave, IMO you're asking for trouble there. (BG's are _notoriously_ sensitive to reflections from the backwaves, because the diaphragm is so easy to move.) A 3" cone widebander would likely be a better choice.
> 
> As for balance, people shouldn't be silly. A little extra mass behind the cabin within the wheelbase won't materially hurt anything. Especially since the S2000 is a fairly heavy car as it is. (Yes, 2800lbs is a heavy car to me!) At worst, distribution MIGHT go to 48/52. Which is fine.


Hmm yeah I've used them in my Accord. I had them in a sealed chamber firing up from the kickpanels. The pillar application will be sealed as well, so no problem with front and rear wave separation. You are right in that they will point down a bit, I'm worried too, not sure how to solve this issue. It will just be the driver one. I hate to have them fire at eachother, I'd rather have them on axis even with the driver one pointing down a bit. I won't ask them to do more than 6khz so upper rolloff is not an issue. Furthermore I won't ask them to do lower than 1.6khz so I won't need lots of airspace in the enclosure. 

A 3" cone widebander will easily be kinda deep for a pillar, it will be in my face. Furthermore the sensitivity is nowhere near 93db. But...yeah give me some to look at. 

The S2000 is heavier because the engine head is heavy on this thing. There is a price to pay for VTEC. There is also a weight penalty for safety. Unlike some roadsters that totally collapse in a rollover the pillars and roll hoops have enough layers to save you. It has a spare. The high xbone frame is also as stiff as they come, that takes a lot of material. Honda only made one cheap move with this car, it gave it a steel tub. It's the only area of improvement as far as shedding weight but imo it would make it unfordable for many of us. Think $100k NSX. It's also a lot easier to mess with steel,anyone can seamweld it, add it rollcage etc.


----------



## DS-21

cvjoint said:


> Tire sizes will increase from 205 front to 255/265 and from 225back to 295.


Be aware that tires that big may take some of the fun out of the car for street driving. Yes, you will have more grip for the track. But IMO part of the fun of a small sports car is sliding it around at near-legal speeds, and with so much contact patch you won't be able to get the chassis to do anything interesting (even with the S/C) until speeds I wouldn't attempt on public roads. 



cvjoint said:


> Hmm yeah I've used them in my Accord. I had them in a sealed chamber firing up from the kickpanels. The pillar application will be sealed as well, so no problem with front and rear wave separation.


Actually, that IS the problem - the backwave will just reflect back through the front of the diaphragm. I would if nothing else try it in a test enclosure before cutting and such.


A 3" cone widebander will easily be kinda deep for a pillar, it will be in my face.



cvjoint said:


> The S2000 is heavier because the engine head is heavy on this thing. There is a price to pay for VTEC. There is also a weight penalty for safety. Unlike some roadsters that totally collapse in a rollover the pillars and roll hoops have enough layers to save you. It has a spare. The high xbone frame is also as stiff as they come, that takes a lot of material. Honda only made one cheap move with this car, it gave it a steel tub. It's the only area of improvement as far as shedding weight but imo it would make it unfordable for many of us. Think $100k NSX. It's also a lot easier to mess with steel,anyone can seamweld it, add it rollcage etc.


That motor is frightfully heavy. I believe a modern small-block Chevy is lighter! But it revs and revs and revs. And I don't really buy the safety argument. I've seen nothing to suggest that the S2000 is safer than an Elise or a Miata. People have gone through rollovers in both with no additional safety equipment and come out without windshield headers collapsing.

The frame is quite stiff, and that adds weight. It boils down to preference, and many people absolutely adore the S2000, for good reason. It's a good car now, and will be one of the few cars from today with any value two decades hence. Honestly, if it was exactly as it is but had 5-7mpg higher performance, the decision would've been much harder for me. 

One would also be remiss in not noting that when GM tried to make a small roadster, they couldn't get it lighter than the S2000 despite sacrificing any trunk room and having a less-powerful engine.


----------



## cvjoint

DS-21 said:


> Be aware that tires that big may take some of the fun out of the car for street driving. Yes, you will have more grip for the track. But IMO part of the fun of a small sports car is sliding it around at near-legal speeds, and with so much contact patch you won't be able to get the chassis to do anything interesting (even with the S/C) until speeds I wouldn't attempt on public roads.
> 
> 
> 
> Actually, that IS the problem - the backwave will just reflect back through the front of the diaphragm. I would if nothing else try it in a test enclosure before cutting and such.
> 
> 
> 
> 
> That motor is frightfully heavy. I believe a modern small-block Chevy is lighter! But it revs and revs and revs. And I don't really buy the safety argument. I've seen nothing to suggest that the S2000 is safer than an Elise or a Miata. People have gone through rollovers in both with no additional safety equipment and come out without windshield headers collapsing.
> 
> The frame is quite stiff, and that adds weight. It boils down to preference, and many people absolutely adore the S2000, for good reason. It's a good car now, and will be one of the few cars from today with any value two decades hence. Honestly, if it was exactly as it is but had 5-7mpg higher performance, the decision would've been much harder for me.
> 
> One would also be remiss in not noting that when GM tried to make a small roadster, they couldn't get it lighter than the S2000 despite sacrificing any trunk room and having a less-powerful engine.


Yeah, surely you won't be able to loosen up the rear that much, that is one point. Breaking and cornering would be insane though. I'm guessing one could also go with a harder compound in 295 to be able to induce more wheelspin and save money on tires. 

I thought the backwave reflects back in all sealed applications. How is the Neo8 any different than a sealed 3" woofer? I was thinking of trying to absorb the rear wave somehow. On HT forums some folks have been very successful implementing fiberglass insulation. There is also that blackhole fancy sound absorber and the deflex pads. Higher frequencies shouldn't be too hard to absorb but it does take away from my enclosure room again. 

The 4cyl DOHC VTEC engines weigh as much as a SOHC V6 but not as much as the OHV V8s. It all comes down to preferences as the HP/lb in these motors come out about the same. With a high rev motor you will have a lot more fun and modulate the pedal easier. With the sheer torque of a simple V6 you will get better 0-60 times and towing capacity. Gas millage will be about the same. Which reminds me if low MPG is all that's keeping you away from an S2k then I have a solution for you: longer gears. This is one of the two reasons the S2000 does not get good gas millage. The other is that peak torque comes very later in the powerband. You can get an '04 and up with longer gears and I think 25 city 30 freeway is attainable. 

I don't have raw data for you on the Miata windshield crashing easier but that was the general idea I got from reading the boards/talking to autocrossers. The first get Miata also does not have roll hoops and it's illegal on some tracks:
From SpeedVentures FAQ:
_ Cars without roll protection behind the seats, such as first-generation miatas, C5 corvettes, and mustangs are not allowed without some form of SUBSTANTIAL aftermarket roll protection. We apologize to any drivers this may exclude, but a track day is simply not worth the risk of driving without a measure of protection. Please contact us with any questions about your convertible. _


----------



## redcalimp5

If I was a single guy with no kids/or they were all grown up, I'd be all over an S2000. I've always really liked these.


----------



## DS-21

cvjoint said:


> Yeah, surely you won't be able to loosen up the rear that much, that is one point.


That sounds less fun to me than the stock tires. Faster, but less fun.



NateTTU said:


> I thought the backwave reflects back in all sealed applications. How is the Neo8 any different than a sealed 3" woofer?


Surface area and rigidity of the diaphragm. 



NateTTU said:


> Which reminds me if low MPG is all that's keeping you away from an S2k then I have a solution for you: longer gears. This is one of the two reasons the S2000 does not get good gas millage. The other is that peak torque comes very later in the powerband. You can get an '04 and up with longer gears and I think 25 city 30 freeway is attainable.


Well, _now_ what's keeping me away from one is owning a Miata! 

But seriously, I'm not getting another car - and if my Miata gets totalled, its most likely replacement is another Miata - until/unless there's a new Lotus Elise that's easier to get in/out of. Besides that flaw, the Elise is the perfect car for me.



NateTTU said:


> I don't have raw data for you on the Miata windshield crashing easier but that was the general idea I got from reading the boards/talking to autocrossers. The first get Miata also does not have roll hoops and it's illegal on some tracks:


Either does the second gen (mine). But you're talking about racing. For serious track driving, I see the point of getting more serious roll protection, and track owners are wise to mandate it. But in terms of getting into an accident on the street, the windshield header is sufficient rollover protection.


----------



## oslouie

Nice. Yellow isn't my color but I'd rock that ride.


----------



## cvjoint

DS-21 said:


> That sounds less fun to me than the stock tires. Faster, but less fun.
> 
> 
> 
> Surface area and rigidity of the diaphragm.
> 
> 
> 
> Well, _now_ what's keeping me away from one is owning a Miata!
> 
> But seriously, I'm not getting another car - and if my Miata gets totalled, its most likely replacement is another Miata - until/unless there's a new Lotus Elise that's easier to get in/out of. Besides that flaw, the Elise is the perfect car for me.
> 
> 
> 
> Either does the second gen (mine). But you're talking about racing. For serious track driving, I see the point of getting more serious roll protection, and track owners are wise to mandate it. But in terms of getting into an accident on the street, the windshield header is sufficient rollover protection.


So you're basically saying the back wave is going to cause havoc on that membrane huh. I was looking at the Hertz ML500 unit:









I thought this was enclosed, but it's dual radiating just like the Neo8. In fact with a rather more common, smaller mylar membrane it's not going to perform better. 

I gotta look up sound absorbers, without the depth to accommodate a woofer, and given the output requirements I have to make one of these planars work. 

I don't blame you for looking at a Lotus, it's as raw as they come. I don't even mind getting over those radiator tunnels to get inside. I hope you have the patience to work with a British car day to day.


----------



## cvjoint

I did a quick search to remember some of the absorber testing results. It looks very very good for the planar. 

Here's a test of 1" wedge type professional acoustical foam (not even solid foam):
http://www.auralex.com/testdata/test/1wedge.pdf

And here is a guy who believes some very common rigid fiberglass panel works better than the leading wedge type pro foam:
Acoustic Treatment and Design for Recording Studios and Listening Rooms

To conclude, solid 1" acoustical foam or some of these home brewed rigid fiberglass panels can easily absorb frequencies in my desired pass band: 1600hz and up, in most cases full absorption can be achieved 1000hz and up.


----------



## hybridspl

Just did some exploration on my S, and can't wait to see how you are going to fit three 12's! Also, are you keeping the convertible top? Mine actually rests on the plastic tray that you removed and I think it would vibrate horrendously if exposed to the subs.

Sidenote: I just pulled an S2000 motor and it doesn't weigh any more than than any of the other comparable Honda motors. My friend and I carried it from the garage to the spare bedro... I mean "engine building clean room". I would guestimate that it weighs 250 - 300lbs. Not exactly a cast-iron boat anchor like most domestic engines.


----------



## Oliver

cvjoint said:


> Or an aluminum hardtop or a carbon fiber hardtop.


Grab one of these if you are wanting *some sound reproduction* when you are daily driving 

*Cabin Gain is nice !*

Very nice car by the way


----------



## Rob J

hybridspl said:


> I would guestimate that it weighs 250 - 300lbs. Not exactly a cast-iron boat anchor like most domestic engines.


Also has absolutely no torque, unlike most domestic engines. There is no replacement for displacement. I think it would be neat to shoehorn an LS series engine in an S2000.


----------



## IBcivic

^yup and then it would handle curves like a chevy cavalier


----------



## irv_usc

interested to see your build. been searching for a long time on s2000 systems but can't find any recent results.


----------



## chad

Out of curiosity why the BG planars AND the vifa tweet? I know from your past installs that this is how you roll but after owning the vifa tweet I can attest to it being a rather capable driver, especially considering how close you are going to be from it. I would almost experiment with the woofer and the vifa with some non permanent mounting methods then if you feel the need to add the planar do it. Losing the planar will make the processing and amplification much easier in an already cramped car. Although I DO love seeing installs where people put 20 pounds of **** in a 10 pound bag 

Beautiful car BTW! If I did not live in Illinois I'd own one now.


----------



## cvjoint

Rob J said:


> Also has absolutely no torque, unlike most domestic engines. There is no replacement for displacement. I think it would be neat to shoehorn an LS series engine in an S2000.


Depends on what you compare. If you compare any non-turbo 2.0 domestic engine to the Honda F20c you will find that Honda has more peak torque and manages to hold it over an enormous rpm band. 

It has been done, an LS3 S2000 weighs a little over 3000lbs. Mine is 2810. You are looking at 200lb increase. 

I'm a big fan of the LS7 engine from the Zo6 Corvette. The strenght of this design lies in packaging and not in torque figures. It has one of the lowest torque/liter ratings out there. 



amitaF said:


> ^yup and then it would handle curves like a chevy cavalier


I just woke up after my first track event. I pulled 1:40 at Streets of Willow CCW yesterday. There were two straights where the Chevy motor swap would help out...and about a dozen turns where the extra weight and difficulty of modulating 470lb/ft of torque would loose lots of seconds. In fact the only time I spun out was because I couldn't control the rear end after downshifting to second, too much torque to abruptly. 

Overall I would say the LS7 motor does not belong in the S2000. For track, street, and even better track/street daily driver a stock S2000 is better car. Furthermore with 50lbs increase, an supercharger or turbo bolt on kit will net you around 400hp, more than enough for street/track. 

An LS7 swap is good for drag and top speed applications. I'm not interested in any of these, both can kill me a lot easier and require a lot less driver input. 



irv_usc said:


> interested to see your build. been searching for a long time on s2000 systems but can't find any recent results.


Yeah, I posted a similar thread on S2KI and I don't think it's very popular to say the least. I tried to kick start some on this site too but no bueno. 



chad said:


> Out of curiosity why the BG planars AND the vifa tweet? I know from your past installs that this is how you roll but after owning the vifa tweet I can attest to it being a rather capable driver, especially considering how close you are going to be from it. I would almost experiment with the woofer and the vifa with some non permanent mounting methods then if you feel the need to add the planar do it. Losing the planar will make the processing and amplification much easier in an already cramped car. Although I DO love seeing installs where people put 20 pounds of **** in a 10 pound bag
> 
> Beautiful car BTW! If I did not live in Illinois I'd own one now.


Yay audio! Ok, well it seems like that Vifa tweeter is deceptive in its ability to play low. The low FS only signifies a flat FR. It has almost no usable xmax. Npdang, Zaph and virtually all users indicated a high crossover point, 3500hz and up. I generally require a bit more output than the average user so maybe 4000hz minimum. It seems like the perfect supertweeter, great csd, sensitivity and a smooth extended FR at the expense of low end performance. 

For a smallish format tweeter that can cross low with decent results I would go with the SB29 at 2500hz. Unfortunately, if you look at my door panel, it covers the upper part of the firing cutout. combine that with the off axis placement of the woofers and the 7" driver will have a hard time getting a good power response in the 2000hz range. Lastly, the B&C drivers have a rather soft cone to get high sensitivity, and that translates to mediocre distortion performance in this range as well. 

Enter the Neo8. It has 93db sensitivity but many FR limitations. For one the sensitivity stop dropping like a rock bellow 1500hz. BG says you can run them down to 200hz, but that's with an enormous baffle and a tight sealed box with a high Q. Most likely the sensitivity still wont be that great down low. Up high, it has a nasty peak at 12000 and drops off like a rock after that. I haven't seen any successful uses of this driver as a low crossing tweeter. It HT they call this an extended midrange. In HT they also use it dipole, I can't. 

I'd love to try it out first but from my experience with this and it's brother the PDR, the FR changes wildly between taped on the pillar and properly sealed. I'll have to build it, work with it and cast off if it fails. 

Weight wise we're looking at 5lb increase in amplifier weight (1/2 of a 4 channel), and maybe another 3 lbs increase from extra wiring and pillar weight. The processor will have 4way capability anyway. I'm willing to put on 8lbs extra to go from 3 way to 4way if it makes an improvement. I think it will, higher soundstage, more power handling, and better distortion performance 1500hz-4000hz.


----------



## moog

Looking forward to seeing the final product, i've got a buddy w/ a built S2000


----------



## cvjoint

a$$hole said:


> Grab one of these if you are wanting *some sound reproduction* when you are daily driving
> 
> *Cabin Gain is nice !*
> 
> Very nice car by the way


You know, I got a great idea for DIYMA style testing. I should test the in car response of the 3 IB 12s in three situations from 20hz to 200hz on the MLS:
1. Top down
2. Top up
3. Top down with a borrowed hardtop 

It takes seconds to put an oem hardtop on.


----------



## DaveRulz

The whizzer cone comment was a joke, I'd rather see a hundred pounds of removable gear that will make a car more enjoyable on a daily basis. To pretend like that is going to ruin the handling of the car is foolish. Especially when you consider how far from the car's handling limits you will be in everyday driving conditions.

The last two iterations of my car have had removable amps and subs via a couple take apart hinges under the rear deck and quick disconnects/NL4, the infinity amps actually have the WECO connectors which make removal of the rack even easier. Two wing nuts, unplug the wecos for speakers, unplug RCA's unplug large forklift style connector on the power and out it all comes. Worked great at the few autocross events I took the car to in that time. 

Really looking forward to seeing what you do with this. Esp after seeing what you had done in the accord. Little car/Big stereo should be freaking sweet!


----------



## mrstangerbanger

i had the same car and did Focal 165v2s in front doors with a Eclipse cd8053 and i did two amps (JL amps) under both seats and a single (Idq)12ich sub in the rear and it sounded great 

i really loved that car and you will too


----------



## cvjoint

^^ Nice! I plan to use Anderson powerpoles all throughout the car. These connectors are simply amazing, from self cleaning feature to the modular design. Molex is simply crap by comparison. A lot of the pro audio connectors are super nice but heavy. 

I was thinking about the wing nuts too for bolting my IB baffle and ease of removal. 
^
How did you fit amps under the seats? I checked the height, there's next to none left if you want the seat to move forward and back. 

The car is amazing, I wouldn't care if I had to keep it into old age


----------



## DaveRulz

re: wingnuts

they work OK, but I'm not sure they're the best solution, simply using bolts or nuts that are the same size as your lugwrench would probably be a better solution. That way you'd always have the tool you needed to remove them onboard (or you could just pack a small ratchet somewhere) it can be tightened down better, and will still be easy to remove


----------



## cvjoint

DaveRulz said:


> re: wingnuts
> 
> they work OK, but I'm not sure they're the best solution, simply using bolts or nuts that are the same size as your lugwrench would probably be a better solution. That way you'd always have the tool you needed to remove them onboard (or you could just pack a small ratchet somewhere) it can be tightened down better, and will still be easy to remove


That's a very nice/original idea but those bolts would be enormous and the lugwrench will not be on board at all anymore (toolbox and spare delete). The tow hook is the only part I'll keep in the car and that one is hand tightened too. I could simply use lugnuts if I were to do that. But you see an IB baffle doesn't require the same clamping force as a 4 lug Accord wheel, or maybe it does :worried:

BTW you haven't seen my finger muscle 

Also If I were to be picky I would much rather use a removable wing bolt as opposed to a nut. 4 bolts that that size permanently attached on the car are a few lbs. The bolt should be removable with the baffle, the nut should stay. It's lighter.


----------



## cvjoint

You know what, the lugnut idea is really good. I might use it, it beats hand tightening for having a nice solid baffle. A carriage bolt soldered to a hefty L-pad can hold it from the back. 

All the amplifiers have arrived now. Have I mentioned how much I love aluminum heatsinks?










Three amplifiers for less than 26lbs. They will put out the following:
90w @4 ohm per Vifa supertweeter
90w @4 ohm per BG neo 8 tweeter
180w @8 ohm per BC midrange
750w @2.66 ohm for the subs or 250w for each IB12


----------



## Austin

subscribed. Looks very cool and looking forward to the results of the three 12's!!


----------



## cvjoint

Does anybody want an IB12? I'm thinking of ordering four of them to get the bulk discount. You would get your IB12 for $125 plus shipping instead of $150 plus shipping. Basically you are getting the bulk discount with me and I'm getting mine.


----------



## cvjoint

Picked up a used Eclipse 7200 MkII headunit from a buddy.

So far I have:
Amplifiers 3 Clarions $550 26lbs
Head/transport Eclipse $200 (weighs less than the oem that's getting replaced, it's a dead head)

Still need speakers:
Subs 3 AE IB12 45lbs $400
Mids B&C 5lbs $220 (Stockers are probably 2lbs)
Tweeters BG and Vifa 3lbs $185

It looks like the total will be a tame $1550, and weigh about 77lbs before wiring, sound deadening, amp rack and speaker baffles/enclosures. 

The 100lbs limit seems achievable through the use of fiberglass, lightweight mdf and foam as sound deadener. I'll try to approach the sound proofing by absorbing the rear wave and road noise as opposed to blocking it with heavier butyl and aluminum mat.


----------



## Jroo

Watching the build. I guess there are enough LS1 swaps that they have started their own forum v8s2000.com. I saw the other day a guy that is selling sub frames for the swap at something like 300 bucks. Around here guys are going to junk yard getting motors out of trucks at junk yard for next to nothing. Go swap heads and cams and get a realiable 350 hp and torque out of the box, sometimes much more. Short of turbo or supercharger, its getting really hard to beat those motors. Anyway looking forward to the build and especilly those Neo drivers.


----------



## cvjoint

^ I had a swap in my other car, It's not for the faint of heart, and my swap was fairly easy, most things bolted up including the transmission. If you are a top notch mechanic and you have a second car and you don't live in California, and you are not risk averse, and you have lots of money and time than a swap is an option. Be very careful with used engines, odds are they are not 100% functional.

Imo there are so many reliable bolt on kits for the s2000 that will give you close to 400hp the LS1 is not a good idea. You'll end up having less HP, more weight, and a harder time modulating that power without losing grip. You have to look at an LS3 or LS7 to get something that's worth working for. Anyway there are so many tradeoffs in engineering I couldn't rank the options, I'm very found of stock reliability and the high level of fun this powerterain offers. I did however entertain the though of an ls7 rx7. In that case the rotary is more inefficient and unreliable than the V8.


----------



## quality_sound

Why don't you use Birch instead of lightweight MDF? It'll easily save you the weight you need.


----------



## cvjoint

quality_sound said:


> Why don't you use Birch instead of lightweight MDF? It'll easily save you the weight you need.


Well if you imagine the baffle: 37"x13" and now take three 11" diamater cutouts, you'll notice there isn't much of a baffle to begin with. It can't weight more than 7lbs even with 1.5" thickness.

I can get the lightweight MDF stuff from a local lumber store, I've used it before it's wicked light and does not splinter like plywood. 

Now, I've read articles where they say doubling the thickness gives you 8 times more rigidity whereas going from mdf to birch amounts to only twice as much rigidity. The dollar/benefit ratio doesn't seem that good, whereas doubling the board thickness is cheap and very effective. But to be fair, baltic birch does seem to be the better material. I'd like aluminum or dry carbon too  I'll check it out at the lumber store, if the cost is inline with its performance I'll buy it.


----------



## ncv6coupe

watching this build as i'm a honda nut, your research to keep that s2000 in full track function and still have a true sq system peaks my interest for sure. 

oh i forgot to ask, how you like that 6 speed tranny? i pulled my j series out and tinkered with it a little(insert high end acura parts here) and needless to say i have NO traction straight up to about 6000 rpm in second gear when i get on it regardless of speed i was traveling, lol


----------



## cvjoint

The transmission is killer. The only better one out there is probably the AP2, year 2004 and up S2000. Those ones have carbon syncros and shorter 1,2 longer 6th. Mine has a slight glitch going from 1 to 2 every now and then but it's not that RPM dependent, some AP1 transmissions are like that picky at some things. I like the one on the Lotus Elise too, but yeah, not as nice. 

To compare, my F23 Accord 5 speed was smooth but disconnected, you don't get any of that metal on metal action/feel even when you max out the mods out there. Still a million times better than Chrysler, Dodge, BMW, Renault ...I don't know anything else other than that Elise. 

Launching the S2000 is tricky. I drop the clutch at 7500rpm, it takes a second or two to fully grasp the pavement and after that there is no slip with my 225 section tires. It's much different than my Accord where the front wheel drive would get slaughtered from a similar motor on similar tires.


----------



## ncv6coupe

cvjoint said:


> The transmission is killer. The only better one out there is probably the AP2, year 2004 and up S2000. Those ones have carbon syncros and shorter 1,2 longer 6th. Mine has a slight glitch going from 1 to 2 every now and then but it's not that RPM dependent, some AP1 transmissions are like that picky at some things. I like the one on the Lotus Elise too, but yeah, not as nice.
> 
> To compare, my F23 Accord 5 speed was smooth but disconnected, you don't get any of that metal on metal action/feel even when you max out the mods out there. Still a million times better than Chrysler, Dodge, BMW, Renault ...I don't know anything else other than that Elise.
> 
> Launching the S2000 is tricky. I drop the clutch at 7500rpm, it takes a second or two to fully grasp the pavement and after that there is no slip with my 225 section tires. It's much different than my Accord where the front wheel drive would get slaughtered from a similar motor on similar tires.


 i have carbon syncros and love "cruising" on the highway around 85 at 2800rpms or so, haha, I use the penzoil synchro mesh in the yellow bottle, that helped some but i dont really harass my car as much as i used to now as its my DD since i sold my 94 ex wagon in immaculate condition(big seller remorse here) if you think launching the s2000 is hard you havent driven a 6 speed 7th gen coupe yet, the weight is the only thing that keeps the front end somewhat straight on acceleration but lets not derail the SQ thread, i could do car talk for hours:blush:. Subscribed


----------



## cvjoint

ncv6coupe said:


> i have carbon syncros and love "cruising" on the highway around 85 at 2800rpms or so, haha, I use the penzoil synchro mesh in the yellow bottle, that helped some but i dont really harass my car as much as i used to now as its my DD since i sold my 94 ex wagon in immaculate condition(big seller remorse here) if you think launching the s2000 is hard you havent driven a 6 speed 7th gen coupe yet, the weight is the only thing that keeps the front end somewhat straight on acceleration but lets not derail the SQ thread, i could do car talk for hours:blush:. Subscribed


Yeah, I cruise at nearly 5000rpm . Since it makes peak torque on the first set of cams at 5500rpm I would love to cruise at 105mph, but the law is no go. I think this car would actually get decent millage at 105mph when tested with other cars at the same speed.


----------



## 60ndown

i see 2 mistakes.

1. its your daily driver and your going to race it?, that might leave you car less if there are any mechanical/accident problems. why not use it as your daily and get another dedicated race/fun car? (go kart with a v8)

2. picking your audio gear based on weight is madness.you want it to sound as good as it can, accept there might be some additional weight.

doing it your current way you end up with a daily driver you wont want to race hard for fear of damage, with mediocre audio.

my 0.2 cents ^.


----------



## ncv6coupe

60ndown said:


> 2. picking your audio gear based on weight is madness.you want it to sound as good as it can, accept there might be some additional weight.
> 
> doing it your current way you end up with a daily driver you wont want to race hard for fear of damage, with mediocre audio.
> 
> my 0.2 cents ^.


he did, 100 pounds, lots of cone area, moderate power, VERY SMALL PATHLENGTHS, its gonna sound effortless, and its "ONLY" a honda, but its a honda, rebuilding a wreck, 3 grand max if you can turn a wrench, well a 10 and 12 mm socket actually, lol:laugh: i crack myself up, sorry guys its late and its the sleep talking>


----------



## cvjoint

^ That's the beauty of the S2000, it's the perfect dual purpose car. It comes with towhooks, helmet holes in the seats, track gearing and a 9000rpm redline for that record setting hp/liter. On the street you have the gas saving, fine idle tame cams, A/C, spare and reliability. 

I've made no noticeable downgrades in quality with the choice of equipment. At least that's what I think, I'm open to suggestions. What can be heavier and sound better, noticeably?


----------



## 60ndown

cvjoint said:


> What can be heavier and sound better, noticeably?


i have no idea 

but take the weight restriction out of the equation and im sure some here will have ideas.


----------



## cvjoint

60ndown said:


> i have no idea
> 
> but take the weight restriction out of the equation and im sure some here will have ideas.


Well one can always use Class A amplifiers or lead for sound deadening. There are ways in which A LOT more weight can make a very small difference. But you don't have to be a weekend racer to appreciate hundreds of pounds of weight savings. 

I do apologize for the thread's demands but I did get some ideas I will throw in the mix like the lugnuts for the baffle and the birch. I'm more of a 90% of the benefit for 10% of the cost and weight kinda guy.


----------



## cvjoint

Well the subs came in and I sent them for Klippel testing at ID. Results are here:
http://www.diymobileaudio.com/forum/klippel-reviews-driver-specs/91158-acoustic-elegance-ib12-8-a.html

It seems like I picked #1 choice for my application. These proved to be the most sensitive subs in 12" trim we've tested. Furthermore they have a spectacular motor on them. The suspension is less than ideal but I will only have 750w for all three at 2.66 ohms. This corresponds roughly to 12mm of xmax at 20hz. With the engine on and high revving there should be no audible distortion even when I feed them close to clipping. 

The high frequency response should also allow me to choose a crossover point as high as 250hz if I so wish. Also note the small dimensions of the driver and ultra low weight. There are lots of neo 12" that weigh more. 

Now waiting on the other speakers to be tested.


----------



## cvjoint

Some pictures showing early progress:

Clad S2k:











Infinite baffle frame skeleton:










Pillar skeleton:










Removable IB baffle:











Mounted baffle:










Behind baffle: removable amp rack:











B&C install:










Trying out new SB Acoustics tweeters, I think I like them more than Vifas:











Finally this is no longer a $2,000 system. I broke down and bought a P99.


----------



## thehatedguy

Those SBs aren't that much bigger than the Vifas.


----------



## jtaudioacc

How do those tweeters sound in the armrest? :laugh:


----------



## BuickGN

60ndown said:


> i see 2 mistakes.
> 
> 1. its your daily driver and your going to race it?, that might leave you car less if there are any mechanical/accident problems. why not use it as your daily and get another dedicated race/fun car? (go kart with a v8)
> 
> 2. picking your audio gear based on weight is madness.you want it to sound as good as it can, accept there might be some additional weight.
> 
> doing it your current way you end up with a daily driver you wont want to race hard for fear of damage, with mediocre audio.
> 
> my 0.2 cents ^.



I wish I would have listened to my father back when he told me not to race a daily driver. I drove my race car daily from '94 to '05 including a 210 mile round trip commute for 6 months. It was always fun driving a 10 second (probably a 9 second car at it's current power level) but I can remember pulling many all nighters working on it to get to work the next day. I'll never do that again.

Cvjoint- I'm looking forward to the completion of this project. That S-2000 has got to be fun on the track. I don't know where in CA you are but have you ever gone to Willow Springs? I was taking the Tl there again in February but I don't think I'll get the timing belt done in time and I'm not risking that. It's so much fun but I always feel guilty for beating on the car.


----------



## thehatedguy

I think he mentioned a track day at the Streets of Willow.


----------



## BuickGN

thehatedguy said:


> I think he mentioned a track day at the Streets of Willow.


Sorry. I need to learn to read better.

In case anyone is interested they're opening Big Willow in Feb. There might still be some slots. Not good for lower powered cars like mine but lots more fun imo.

Back sort of on topic, the IB setup is so nice because it means not having to remove 200lbs of equipment to go to the track. Even though I didn't do it often I dreaded removing the massive bandpass each time.


----------



## cvjoint

I've done streets of willow twice now. It's a blast in the S2k. Other than the two straights everything is technical enough to give the S a chance against far more powerful cars. I've done 1:38 as my best time, not very good but ok considering it's fully stock and I'm a newb. There was an older gentleman with minor mods doing 1:30! That's way fast. 


There are fewer downsides to tracking an everyday car with the S2k. For one it doesn't break down that easy. If you see an S getting towed at the track it's because they put some stupid aftermarket parts on them and they failed. However, once you spin out there are literally pounds of rocks and dirt that fill the cabin up. That's hours of cleaning and honestly it never has that new car look ever again haha. Then there are lots of chips on the undercarriage and side sills. The tweeters will get their fair share of dirt and I'm not too happy about it. 

Since I got the P99 recently I won't be going to the track anytime soon. Gotta save up a bit. 

The SB29 is slightly larger than the Vifa but it has almost twice the surface area, twice the power handling and it's a full 3 db more sensitive. I'm really liking them. 

Weight wise I think I easily surpassed the 100lb limit. The one thing I forget to account for is the wiring. I didn't weigh it but I'm guessing all wiring and connectors are about 20lbs putting me easily at 120lbs or so. 90lbs is removable however.


----------



## t3sn4f2

nevermind, wrong thread


----------



## vactor

kickass install. just got my S2k and going to be doing an install in one as well!


----------



## cvjoint

vactor said:


> kickass install. just got my S2k and going to be doing an install in one as well!


Thanks mate! 

I should probably redirect everyone to the finished product:
http://www.diymobileaudio.com/forum/diyma-member-build-logs/106133-2001-honda-s2000-single-seat.htmll

I didn't use the wheel lugnut idea. The studs would be too heavy for the job and I would still need a washer to have it clamp on the baffle. In a few years I might strengthen the baffle a bit though and add some sort of machine screw design. The wood screws will catch on the fiberglass for only so many times before the fiber will let go.


----------



## nineball

i can't even begin to imagine what three 12s will sound like in that tiny cabin. i have a pair of 8s in my 83 911 and they are *almost* too much for my tastes and i love large amounts of low end. good luck.


----------



## cvjoint

nineball said:


> i can't even begin to imagine what three 12s will sound like in that tiny cabin. i have a pair of 8s in my 83 911 and they are *almost* too much for my tastes and i love large amounts of low end. good luck.


Well the soft top doesn't add much. If I were to get a hardtop at some point in time it would really shine. With the top down they are merely adequate haha.


----------



## nineball

well mine is a targa, no roof to speak of


----------



## cvjoint

This is a sad day, for I found a way to improve the sound in this vehicle. 

Thinking of getting these guys for midbass:










Tang Band W69-1042J 6"x9" Subwoofer

and replacing the Neo 8s with two of these per side:










Faital Pro 4FE30 4" Speakers - Faital Pro 4FE30 mid-high speaker has a wide frequency range from 90Hz to 20kHz and has a lightweight neodymium magnet - Faital Pro 4FE30 60 watt 3" has an efficiency of 91dB SPL for all high quality mid-high applicatio

They are so effing cheap too I can barely resist getting the credit car out.

What do you guys think?

I would be able to cross the midbass down to 63hz 24db like I always 
wanted. 
The the Faitals could be crossed down to 200hz in the pillars. 

The midbass output would increase, midrange would remain the same.

The soundstage will be moved up front and lifted entirely to the ear level. 

Then the vocal range would all be reproduced from one (well two)drivers the Faitals.


----------



## fish

About the Faitals... are you gonna seal 'em up or leave them opened up in the back? Also, where would comb filtering start to come into play?


----------



## cvjoint

fish said:


> About the Faitals... are you gonna seal 'em up or leave them opened up in the back? Also, where would comb filtering start to come into play?


I was gonna use the Neo 8 sealed pod. It just needs a little trimming to fit two of these guys. It's about .2 ft3 in internal volume. It should amount to .8 Q. Higher than I like but maybe manageable. That's also before polyfill.

EDIT: comb filtering shouldn't be an issue. I'll still have the Vifa 3/4 domes to take over from 6khz up.

"Unless you can get your drivers very close together your high end response will suffer slightly. This depends on the distance between the drivers. For example we'll take a 4" driver, assuming the edges of the drivers are touching so centers are right at 4" apart. Taking this into account we can find the frequency point where the line will begin to lose directivity, and I believe at approximately four times this frequency(1/4 wavelength frequency) the line will begin to exhibit audible comb filtering and the high end response will begin to decrease. Now, to do this we need to find the frequency with a 4" wavelength. We use this equation:

speed of sound = freq x wavelength

Now the speed of sound at STP = 331.45 m/s at STP with dry air, but to get a more realistic number, calculating at 70degrees F with 50% relative humidity the speed of sound would be around 344 m/s. This gives a difference of about 120Hz in this case compared to using the STP value.

So, the wavelenght is 4" and converting to meters we get .1016 m. Plugging into the equation we get:

344m/s = freq x .1016 m

freq= 3391Hz

This is the point where the line will begin to lose directivity with a 4" driver, and at double this point, 6738Hz, comb filtering will begin to take effect. I haven't been able to do any expermineting yet to determine at what point the comb filtering becomes audible though in relation to this frequency. I have been taking to someone with more real world experience with line arrays, and his would guess say that likely around 13,500Hz, double the frequency where the comb lines begin to take effect they would be come audible. "

http://www.htguide.com/forum/archive/index.php4/t-3593.html


----------



## cvjoint

The 6x9 TB midbasses won't fit, no matter what I do. It's all in this picture:









Time to look for a midbass natured trunckated 7" since that's all this car allows for. Exhibit 1:










Depth will be a problem unlike the B&C but I made bigger things fit in tighter places before.


----------



## t3sn4f2

cvjoint said:


> I was gonna use the Neo 8 sealed pod. It just needs a little trimming to fit two of these guys. It's about .2 ft3 in internal volume. It should amount to .8 Q. Higher than I like but maybe manageable. That's also before polyfill.
> 
> EDIT: comb filtering shouldn't be an issue. I'll still have the Vifa 3/4 domes to take over from 6khz up.
> 
> "Unless you can get your drivers very close together your high end response will suffer slightly. This depends on the distance between the drivers. For example we'll take a 4" driver, assuming the edges of the drivers are touching so centers are right at 4" apart. Taking this into account we can find the frequency point where the line will begin to lose directivity, and I believe at approximately four times this frequency(1/4 wavelength frequency) the line will begin to exhibit audible comb filtering and the high end response will begin to decrease. Now, to do this we need to find the frequency with a 4" wavelength. We use this equation:
> 
> speed of sound = freq x wavelength
> 
> Now the speed of sound at STP = 331.45 m/s at STP with dry air, but to get a more realistic number, calculating at 70degrees F with 50% relative humidity the speed of sound would be around 344 m/s. This gives a difference of about 120Hz in this case compared to using the STP value.
> 
> So, the wavelenght is 4" and converting to meters we get .1016 m. Plugging into the equation we get:
> 
> 344m/s = freq x .1016 m
> 
> freq= 3391Hz
> 
> This is the point where the line will begin to lose directivity with a 4" driver, and at double this point, 6738Hz, comb filtering will begin to take effect. I haven't been able to do any expermineting yet to determine at what point the comb filtering becomes audible though in relation to this frequency. I have been taking to someone with more real world experience with line arrays, and his would guess say that likely around 13,500Hz, double the frequency where the comb lines begin to take effect they would be come audible. "
> 
> HTGuide Forum - Line arrays


Plug in the PLD numbers for the two drivers instead of going by the home baffle CTC spacing model.


----------



## cvjoint

t3sn4f2 said:


> Plug in the PLD numbers for the two drivers instead of going by the home baffle CTC spacing model.


I kinda lost you on this one. They will be right next to each other so the calculations should work exactly.


----------



## t3sn4f2

cvjoint said:


> I kinda lost you on this one. They will be right next to each other so the calculations should work exactly.


Nevermind, it's late. :blush:


----------



## cubdenno

Thanks for the link to those 4's!! I want to give them a look!

Love the car!!


----------



## Thrill_House

Im glad people are finally starting to use those faital 4" drivers in an automotive application, I have been eyeing them for quite a while for a future project and would love to hear reviews from people using them in their own vehicles.


----------



## cvjoint

Thrill_House said:


> Im glad people are finally starting to use those faital 4" drivers in an automotive application, I have been eyeing them for quite a while for a future project and would love to hear reviews from people using them in their own vehicles.


Sigh, not helping much. I lost all day looking these guys up. I suppose I'll get them. So much for 1 year of planning, I could not account for new product hitting the market.

BTW, it appears Faital has been in the game for decades, certainly older than 18sound for example. They just never extended to the US until lately. 

I'll get 4 of them and report back. I wish I could get them tested. Erin is between houses maybe I'll hit up Zaph, Mark K. or Augerpro to test a couple.


----------



## cvjoint

cubdenno said:


> Thanks for the link to those 4's!! I want to give them a look!
> 
> Love the car!!


Thanks mate! It looks like I might have found the Neo 8 a match in these Faital drivers. Until now no combo of the same footprint could belt out as much low distortion sound. 

I have something else for you to gander at:

http://www.audax-speaker.de/index.php?module=shop_articles&index[shop_articles][action]=details&index[shop_articles][category]=11&index[shop_articles][data][shop_articles_id]=105&lang=en

It's a redesigned Neo 8. It has the same corrugated foil used in the Neo 10. US might never get it.


----------



## fish

George,

Did you by chance model a pair (per side) of the 3FE20's in comparison to the 4FE30's? If so, what were your results?


----------



## cvjoint

fish said:


> George,
> 
> Did you by chance model a pair (per side) of the 3FE20's in comparison to the 4FE30's? If so, what were your results?


Yep, I model everything. 

I think I know where you are going. There is something fishy  about the sensitivity on the 3". There is no way it's as high as the 4". You would be right I think.

Here's what I got:

89.64db sensitivity for the 4"
86.47db sensitivity for the 3"

No way in heck they are just as loud with one playing 10hz lower. The 4" has twice the surface area. 

I'm now leaning on getting the 3". I emailed Zaph to send at least a couple to him. The 4" might not fit, and if they do it will look nasty. Then there is the issue of comb filtering. Apparently in nearfield comb filtering is twice as bad so I used half wavelength. Then if I account for the basket in the CTC spacing it gives me a pretty low crossover point. Then the pod might not have enough room to breathe so Q might be too high. Unlike some other stars on this board I don't like Q over 7, it's boomy and ringy. 

Anywho, I'm hoping they will test at 84db at least, that would still be twice as loud as the Fountek, which would be my second choice. I like the F89EX:










^^ sexiest and best 3" out there imo. Unless the Faitals perform better I'll buy 4 of these. I already have the TB3s but they don't tickle me the same.


----------



## jalba

For a guy who has such issues with the weight of his equipment, why on earth would you use 3 12's just to handle 750W of bass? And now you're getting more midbass because your IB didn't sound good. You could have gotten a single 10" or 12" and put 2KW to it, and in a tuned ported enclosure with no weight increase over the 3-12's IB setup, and had all the bass and midbass you could want.

And who puts tweeters in their armrest? 

BTW I used to sell Hondas and drove S2000's occasionally, and was not impressed at all. Yeah, at 6K they start to move a little, but getting to 6K+ takes a while compared to engines with actual torque.


----------



## cvjoint

jalba said:


> For a guy who has such issues with the weight of his equipment, why on earth would you use 3 12's just to handle 750W of bass? And now you're getting more midbass because your IB didn't sound good. You could have gotten a single 10" or 12" and put 2KW to it, and in a tuned ported enclosure with no weight increase over the 3-12's IB setup, and had all the bass and midbass you could want.
> 
> And who puts tweeters in their armrest?
> 
> BTW I used to sell Hondas and drove S2000's occasionally, and was not impressed at all. Yeah, at 6K they start to move a little, but getting to 6K+ takes a while compared to engines with actual torque.


Because "handling" power is not in my system design. If you just want things to handle power why don't you feed 20kw into a 2x4? It's far more important what a speaker does with the watts you give it. I don't want to generate noise, I want music. Big difference. I could throw all 750w into one sub, it will "handle" it. 

Ported designs do NOT increase output across the board. You can't tune a single driver for 20hz and 80hz. And then why would you want to? The point is not that subwoofers can't reproduce midbass, but that the stage gets pulled back if you dial them in like that. The frequency response is fairly flat down to 20hz, a ported design would do nothing useful for sound shaping. 

The IB setup in whole is 50lbs. That's not that much. Most single ported designs weigh around there and they don't have the same overall output. Then there would be no trunk space left either. 

Have you tried changing gears before? The s2k comes with 6 and they are hella short. All I generally do is flick the shift lever in a lower gear to get to 6k rpm. 

I put tweeters in my armrest so I can pet them. There is something about concentric circles that gets me aroused. It makes long drives a pleasure. You should try it.


----------



## jalba

So then your IB 3 12's only pushing 750W would be better than a Morel Ultimo 12" (15 lbs.) in its recommended 1.5 cube sealed box (~15 lbs.) that pushes 1000W of clean power?

Aren't IB's and walls more about peak output and not SQ? And no, you can't tune a single driver from 20hz to 80hz, but an Ultimo in its rec. enclosure would probably be pretty damn flat from 30-80. How did your IB handle 20hz? 80hz?

And if you aren't worried about output and power, then why not just 1 weak 250W 12" in your IB? If you want speakers to piss rainbows into the cabin instead of allowing you to feel your music, why load up 3-12's? And why would you do that when you could have a single 12" (Ultimo) do the job even better than the 3?


----------



## Brian Steele

cvjoint said:


> Because "handling" power is not in my system design. If you just want things to handle power why don't you feed 20kw into a 2x4?


LOL...




cvjoint said:


> I put tweeters in my armrest so I can pet them. There is something about concentric circles that gets me aroused. It makes long drives a pleasure. You should try it.


LMAO - sig-worthy..

In one of my previous cars, I mounted the tweeters below the door-handles and just above the armrests. Why? Well, they sounded best there, duh...


----------



## cvjoint

jalba said:


> So then your IB 3 12's only pushing 750W would be better than a Morel Ultimo 12" (15 lbs.) in its recommended 1.5 cube sealed box (~15 lbs.) that pushes 1000W of clean power?
> 
> Aren't IB's and walls more about peak output and not SQ? And no, you can't tune a single driver from 20hz to 80hz, but an Ultimo in its rec. enclosure would probably be pretty damn flat from 30-80. How did your IB handle 20hz? 80hz?
> 
> And if you aren't worried about output and power, then why not just 1 weak 250W 12" in your IB? If you want speakers to piss rainbows into the cabin instead of allowing you to feel your music, why load up 3-12's? And why would you do that when you could have a single 12" (Ultimo) do the job even better than the 3?


The 3 IB 12s will do better yes. Power handling has 2 dimensions, one is thermal the other is mechanic. While Morel claims their driver has a power rating of 1,000W it is just a thermal reading. The motor on a Morel is nothing special, there are plenty of choices with 12mm of xmax. Model that sub in the factory recommended box and look at excursion. Linear stroke will probably be exceeded at 200w. In keeping the distortion levels below audible thresholds no more than a couple hundred watts is ever needed. 

Going from 200w to 1000w will not net you very much output either. The motor strength, or BL, drops with excursion and it's one of the prime reasons linear boundaries are exceeded. As the motor strength drops you have to feed it exponentially more power to get the last db. I seriously doubt this thing will handle 1,000w even thermally for anything more than a short burst at midbass frequencies. 

SQ as I see it is maximizing output while minimizing distortion. Distortion is of two kinds, linear and nonlinear. IB in this car goes flat down to 23hz or so. The frequency response is +- 3db from 25hz to 70hz WITHOUT any EQ.:










Mesh in the the rest of the speakers and a bit of EQ.:









That is +-3db 20hz to 20,00hz. For reference, a killer set of home audio floorstanders to that but before you put them in a room and they interact with the environment. The tests were done with me in the seat at the listening position and averaged over 30+ mic positions. So linear distortion is extremely low.

Moving on to nonlinear distortion:









That shows harmonic distortion at 115db for the whole car. If you look at 20hz-100hz for the sub, distortion is between .9%-5%. Pretty much nobody can pick up distortion under 10% at bass frequencies, and definitely not in a car. 

So can the subs handle 20hz? Yes, with low distortion at that. Can they handle 80hz, certainly. I could even cross them at 180hz as they are flat up to there and distortion is very low in the high frequencies. The soundstage will be crap but it's easily done. In fact these subs are good to at least 500hz but the amplifier has a limited bandwidth. 

The real comparison would be between the AE IB12 and Morel in the same 2 ft3 sealed box. I bet the AE would be as good or better in distortion at just about every output level. Why? The motor is superior. You are looking at a full copper sleve on the pole piece. It also probably has 30% flatter BL as well. It would be a tie in the suspension test and thermal tests. 

Yeah, I care about output, and therefore low distortion as well. That IS why I use 3 instead of one. I use the AE subs over the Morel because I think they are better.


----------



## jimmy2345

jalba said:


> r?
> 
> Aren't IB's and walls more about peak output and not SQ?



Are you lost?


----------



## BuickGN

jalba said:


> So then your IB 3 12's only pushing 750W would be better than a Morel Ultimo 12" (15 lbs.) in its recommended 1.5 cube sealed box (~15 lbs.) that pushes 1000W of clean power?
> 
> Aren't IB's and walls more about peak output and not SQ? And no, you can't tune a single driver from 20hz to 80hz, but an Ultimo in its rec. enclosure would probably be pretty damn flat from 30-80. How did your IB handle 20hz? 80hz?



How about the opposite. IBs are about SQ and you need lots of cone area for good output. These subs will play very flat from 20hz to out past 90hz. IB will play low end like no other and with these subs you can play midbass with them if you choose to. My current system with two of their 15s IB is by far the cleanest and the best sounding I've ever owned or heard.


jalba said:


> And if you aren't worried about output and power, then why not just 1 weak 250W 12" in your IB? If you want speakers to piss rainbows into the cabin instead of allowing you to feel your music, why load up 3-12's? And why would you do that when you could have a single 12" (Ultimo) do the job even better than the 3?


Because number one, the AEs have super low distortion and having 3 of them running less power with less excursion lowers distortion even more. That single 12 is not going to compare to the AE 12s in SQ or output. Number two, they do a lot more with the power that is given to them. I had to cut the gain waaaay back on my amp when I went with these subs. I modeled the AE IB15 against the 15" Tempest X I was previously running before and it would take over 1,000 watts on the Tempest to reach what the IB15 does with 300 watts. So who cares about how much power is sent to them?


----------



## fish

cvjoint said:


> Yep, I model everything.
> 
> I think I know where you are going. There is something fishy  about the sensitivity on the 3". There is no way it's as high as the 4". You would be right I think.
> 
> Here's what I got:
> 
> 89.64db sensitivity for the 4"
> 86.47db sensitivity for the 3"
> 
> No way in heck they are just as loud with one playing 10hz lower. The 4" has twice the surface area.
> 
> I'm now leaning on getting the 3". I emailed Zaph to send at least a couple to him. The 4" might not fit, and if they do it will look nasty. Then there is the issue of comb filtering. Apparently in nearfield comb filtering is twice as bad so I used half wavelength. Then if I account for the basket in the CTC spacing it gives me a pretty low crossover point. Then the pod might not have enough room to breathe so Q might be too high. Unlike some other stars on this board I don't like Q over 7, it's boomy and ringy.
> 
> Anywho, I'm hoping they will test at 84db at least, that would still be twice as loud as the Fountek, which would be my second choice. I like the F89EX:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> ^^ sexiest and best 3" out there imo. Unless the Faitals perform better I'll buy 4 of these. I already have the TB3s but they don't tickle me the same.



The 3db differential is more like what I imagined. Fishyness I tell ya! 

So how much worse off is it with comb filtering in the nearfield? Would your crossover point be around 3k on the 4"? How about the 3"?

I didn't want to sound rude in an earlier post, but I was curious how you'd pull off dual 4"ers in those enclosures you made (which are bad-ass btw) without issues?

Those Fountek's are nice, I got the FR88's on-axis in my pillars playing 250-315hz & up. I'm looking for something with more output though, because they are definately the weaklink in my system. I was also curious what you came up with on the 3FE20's used in pairs, because I've owned a pair for a while now & have considered using 2 per side to get the output I need. Where did they start to lose a lot of their steam?


----------



## cvjoint

fish said:


> The 3db differential is more like what I imagined. Fishyness I tell ya!
> 
> So how much worse off is it with comb filtering in the nearfield? Would your crossover point be around 3k on the 4"? How about the 3"?
> 
> I didn't want to sound rude in an earlier post, but I was curious how you'd pull off dual 4"ers in those enclosures you made (which are bad-ass btw) without issues?
> 
> Those Fountek's are nice, I got the FR88's on-axis in my pillars playing 250-315hz & up. I'm looking for something with more output though, because they are definately the weaklink in my system. I was also curious what you came up with on the 3FE20's used in pairs, because I've owned a pair for a while now & have considered using 2 per side to get the output I need. Where did they start to lose a lot of their steam?


Here is all the modeling so far:










Challengers:
Brown 2xFaital 3"
Purple 2xFountek 3"
Yellow CSS SDX7 

Incumbent
B&C 7"

As you can see the B&C just demolishes the CSS+any 3" combo 100hz and up. I pull in 180W for the 7s and 100w for a pair of 3"s. That's what I have on tap and that's what they can handle at most anyway. The CSS does have a bunch more output from 63hz to 100hz. 

*Faital vs. Fountek*
They both seem to be doing about .7Q in my 100 in3 pods. So there is enough room in pods for them. The Founteks do require a bit more room than the Faital .72 vs .69 Q. Any 4 combo I've tried ends up over 1Q so out they go. 

Crossover wise the Fountek is supposed to have 5mm of xmax vs 1.8mm for the Faital This is the classic HiFi vs Pro Audio tradeoff. More low end extension for the HiFi driver but it will lose in the SPL comparison. In the picture I have the Faitals at 250hz 36db slope and they reach 2mm excursion at 100w. The Fountek are reaching 2.5mm of excursion at 100w but with a lower crossover of 200hz 36db. I don't trust the Fountek xmax, it's ridiculous. It probably has 3mm of xmax at best. Overall I would say the Fountek can be crossed 180hz when the Faitals go 250hz. I wish I had a Klippel test to go off of to know for sure. 

SPL wise the Faital takes the lead: 86.5db vs 83.9db. The Faitals are twice as loud. This means that when used in pairs they can get 109db while the Founteks can only put out 106.5db. Now Zaph tested the Fountek version 88 at 81.5db. That means we could still be overestimating the output by as much as 2 db. 

I'm thinking of ditching the B&C Neo 8 combo for the SDX Faital combo. I would be losing 3db worth of output from 100hz to 1,600hz. In turn I get a lower midbass crossover 63hz vs 100hz and the entire vocal range on the dash. This is a classic dynamics vs. staging battle. 

*On to the Comb Filtering:*
Previously the analysis did not count for basket room. If you account for the basket and the 3" Faitals are touching eachother the required crossover is 8,400hz and up using the rule from the quote I gave earlier. 

You are not going to like the sound of this but the papers I've seen require half wavelenght rule of thumb for nearfield. That's bad. 4200hz would be the max crossover point with the Faitals such that there are no comb filtering effects. With the Founteks it's even worse since the basket is not truncated, 3900hz. I sure hope these rules of thumb don't work well or that I'm using the wrong ones.


----------



## fish

Had to give you a "thanks" on that post! Very helpful & informative. 

I nervously crossed the FR88's @ 200hz w/36db slopes on the P01, PLUS 24db slope on the HD600/4 & it still sounded strained. But, mine are not sealed & you have an extra pair of them. 

One of the reasons I like the 3FE20's is how close you can mount them next to each other. I think the additional 3db output would get me close to matching up with my Faital W10N4-200's without having to attenuate them so much.

I've considered using a HE mid like the B&C, Audax, etc. in the kicks mated up with the B&G Neo3 in the pillars, but am afraid I'll lose all the midrange up on top of the dash that I've become so accustomed to.  Tough decisions...

So you're wanting to cross the mids & tweet around 6k, correct? Does comb filtering become even more of an issue when you mount the mids off-axis?


----------



## cvjoint

fish said:


> Had to give you a "thanks" on that post! Very helpful & informative.
> 
> I nervously crossed the FR88's @ 200hz w/36db slopes on the P01, PLUS 24db slope on the HD600/4 & it still sounded strained. But, mine are not sealed & you have an extra pair of them.
> 
> One of the reasons I like the 3FE20's is how close you can mount them next to each other. I think the additional 3db output would get me close to matching up with my Faital W10N4-200's without having to attenuate them so much.
> 
> I've considered using a HE mid like the B&C, Audax, etc. in the kicks mated up with the B&G Neo3 in the pillars, but am afraid I'll lose all the midrange up on top of the dash that I've become so accustomed to.  Tough decisions...
> 
> So you're wanting to cross the mids & tweet around 6k, correct? Does comb filtering become even more of an issue when you mount the mids off-axis?


Haha, thanks. I feel like we are on Facebook with these things. 

I discovered one thing today, Fountek rates xmax as peak to peak not one way. That makes more sense. Your Fountek therefore only have 1.5mm one way which is what I saw in Zaph's TS parameters. The 89 model does have more gap and a beefier motor. Claimed xmax is 5mm or 2.5mm one way. That aligns better with your experience. 

I'm a bit split between the 89 and the Faital. If both xmax ratings are true 2.5mm and 1.8mm then the crossover points are 200hz and 280hz for the Faital. That's a big difference, but so is 2.5db of output. Tough choices. I kinda want the Faitals to suck because the Founteks are hella sexy by comparison :laugh:

The difference between a 7" pro audio midrange and a 3" hi fi driver is massive in terms of output and distortion. Even when used in pairs the pro audio driver demolishes in dynamics. 

I'm thinking the Neo 8-s and SDX combo would rock crossed at 400hz. But...I really don't want to slice the midrange at 400hz, 200hz would be ideal. 

I would cross at 4,000hz to prevent the drivers from beaming and CF issues. Mine are 5-10 degrees off axis at most. Comb filtering gets worse if you go off axis more:
"Off-axis measurements with the speaker horizontally placed, as it would be when used as a center channel. If you remain witn 15-20° off-axis at the edges I think that there will be no trouble. For most folks sitting on a couch 2-3M back, this is reasonable. However, as you can see the off-axis measurements at 30° and above are rather dismal. On-Axis (yellow), 15° off-axis (red), 30° off-axis (green), 45° off-axis (pink), and 60° off-axis (blue)."











found here:
HTGuide Forum - Unique question about comb filtering of speakers...

I thought I could maintain my dynamics with these two Faitals and gain a better soundstage but it's starting to look like a whole bag of tradeoffs. Sigh.


----------



## jc1282

i think someone spilled some yellow paint on your car


----------



## Tsunami sound

Nice ride, you really took it apart!


----------



## cvjoint

Tsunami sound said:


> Nice ride, you really took it apart!


Well, to some extent the quality of the installation is figuring out what space you can tap into for speaker use. There are guys that go a step further and cut their dashboard apart, I'm not that hardcore. The dash is always safe in my cars. 

There is not much that I have to do to return it to stock, I only have to buy the rear tray which I buchered, but all the other plastics and spare parts are easily reinstalled. It would take me less than 6 hours to put this car back to stock and sell it. Not that I ever want to, the only times I let go of my cars are when the chassis twists out of shape. Not much you can do then. You can't throw a limp chassis in corners. 

RIP 2000 Honda Accord


----------



## blownrunner

redcalimp5 said:


> If I was a single guy with no kids/or they were all grown up, I'd be all over an S2000. I've always really liked these.


And by the time you can practically own one and have the finances, you wont be able to find one...


----------



## cvjoint

blownrunner said:


> And by the time you can practically own one and have the finances, you wont be able to find one...


There are so many in California, and well Florida you are bound to find one at every corner. Go in the rust belt and yeah they are rare. Overall they are rare but 50% of them are probably sold in these two states. Luckily they last a long time. My buddy has one with 250,000 miles on, still revving to 9k rpm. 

Fish, I found the replacement for the B&C/BG Neo 8 combo, well two replacements. 

Option 1:
Dual Faital Pro 4s + dual passive radiators. The passive radiators would go here:








Passive radiators:









SPL: 112db 
Power: 100w @ 4 ohm
Crossover: 200 hz 4th order
Frequency range: 200hz-3,400hz (comb filtering limited)
Faital excursion reached: 1.3mm out of 2.7mm xmax
Passive radiator excursion max reached: 1.5mm out of 7mm

Option 2: Tripple Peerless 2.5 full range drivers with dual passive radiators:










SPL: 109db 
Power: 150w @ 2.33 ohm
Crossover: 200 hz 4th order
Frequency range: 200hz-4,800hz (comb filtering limited)
Peerless Xmax reached: 2mm out of 2mm
Passive radiator excursion reached: 1.5mm out of 7mm


Both would fit in the pillar pods. The passives would be a little showy, not much I can do about that. Option one would keep up with a 7" pro audio driver in output, it has the surface area equivalent of a 7" and they are pro audio. Option two has a wider bandwidth but trades off output, it's only half as loud. Harmonic distortion would be higher in option 2 due to xmax being reached but not bad at all.

Heck, the dual Faital combo is so good you can cross it at 100hz 1st order. It just has a dropping response bellow 200hz. Cross the midbass 100hz 1st order and you got yourself a nasty setup. The entire vocal range on one driver. Passive radiator line arrays are cool!


----------



## fish

cvjoint said:


> There are so many in California, and well Florida you are bound to find one at every corner. Go in the rust belt and yeah they are rare. Overall they are rare but 50% of them are probably sold in these two states. Luckily they last a long time. My buddy has one with 250,000 miles on, still revving to 9k rpm.
> 
> Fish, I found the replacement for the B&C/BG Neo 8 combo, well two replacements.
> 
> Option 1:
> Dual Faital Pro 4s + dual passive radiators. The passive radiators would go here:
> 
> 
> 
> 
> 
> 
> 
> 
> Passive radiators:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> SPL: 112db
> Power: 100w @ 4 ohm
> Crossover: 200 hz 4th order
> Frequency range: 200hz-3,400hz (comb filtering limited)
> Faital excursion reached: 1.3mm out of 2.7mm xmax
> Passive radiator excursion max reached: 1.5mm out of 7mm
> 
> Option 2: Tripple Peerless 2.5 full range drivers with dual passive radiators:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> SPL: 109db
> Power: 150w @ 2.33 ohm
> Crossover: 200 hz 4th order
> Frequency range: 200hz-4,800hz (comb filtering limited)
> Peerless Xmax reached: 2mm out of 2mm
> Passive radiator excursion reached: 1.5mm out of 7mm
> 
> 
> Both would fit in the pillar pods. The passives would be a little showy, not much I can do about that. Option one would keep up with a 7" pro audio driver in output, it has the surface area equivalent of a 7" and they are pro audio. Option two has a wider bandwidth but trades off output, it's only half as loud. Harmonic distortion would be higher in option 2 due to xmax being reached but not bad at all.
> 
> Heck, the dual Faital combo is so good you can cross it at 100hz 1st order. It just has a dropping response bellow 200hz. Cross the midbass 100hz 1st order and you got yourself a nasty setup. The entire vocal range on one driver. Passive radiator line arrays are cool!



Whoa! That's genious! Would've never thought of something like that.

Out of those two I'd definately go with the Faitals. Man, now you've REALLY got my wheels churnin'.

What brand of PR's are those? Oh yeah, forgive my ignorance, I'm not really sure how to phrase this question but... what frequencies will actually radiate from the PR's? I'm not sure how PR's work in this manner, as far as causing cancellations, smearing, or something of that nature.


EDIT: I found those TB PR's on PE. My first instinct was to go to Madisound, where I did find the Peerless. So what frequency band will these actually help boost?


----------



## cvjoint

fish said:


> Whoa! That's genious! Would've never thought of something like that.
> 
> Out of those two I'd definately go with the Faitals. Man, now you've REALLY got my wheels churnin'.
> 
> What brand of PR's are those? Oh yeah, forgive my ignorance, I'm not really sure how to phrase this question but... what frequencies will actually radiate from the PR's? I'm not sure how PR's work in this manner, as far as causing cancellations, smearing, or something of that nature.


The PRs are Tang Band from Parts Express. $7 a piece on special. Peerless has a 3.5 I can use too but the resonant frequency is too low to bring in any useful output. 

The PRs augument the low end response by moving about. It's the same as a port design but in this case the space requirements require passive radiators. They create some phase distortion but it's usually more than offset by the extra output. You've seen computer speakers with ports before right? Same thing. 

Haven't tried a PR setup before but I got the itch several times. B&C recommends a ported design for the 7"s as well. Think about it, flat to 63hz in a 7" with more output than you can dream of from any other 7". These 7"s in a PR are equivalent to a 10" midbass but with extended response.


----------



## fish

Hmmm... I'm VERY intrigued by this.

If you have time, would you mind modeling up both the 3" & 4" Faital drivers (just a single) with one of those TB PR's in it's optimum sealed enclosure?


----------



## cvjoint

fish said:


> Hmmm... I'm VERY intrigued by this.
> 
> If you have time, would you mind modeling up both the 3" & 4" Faital drivers (just a single) with one of those TB PR's in it's optimum sealed enclosure?


The question you pose is very important here. You want to vary the enclosure size, speakers, passive radiators, and passive radiator weights to get the desired response. 

I basically plotted the 4,3 in their optimal sealed boxes for .7Qtc. Then I used the same box but added the passive radiator. Here's what I got:










Red 4 sealed
Purple 4 PR
Yellow 3 sealed
Brown 3 PR

As you can see just adding a port to the sealed box does nothing in the case of the 4. I have 40watts entered and they reach xmax at 200hz. If you want to cross them at 160hz, you have to cut down the power to 20watts to keep within xmax. The PR setup will have slightly lower distortion 90hz to 300hz but almost not noticeable. 

In the case of the 3 things are very interesting. At 15watts the 3 reaches xmax at 200hz in sealed but 160hz in PR. Adding the passive radiator allows you to cross lower for the same xmax. Since most of the distortion in a full range 3 is due near the High Pass crossover the passive will have reduced distortion if crossed at 200hz or the same but more bandwidth if crossed at 160hz.


In practice, this is how I do things. Active drivers are better than passive drivers. If I had to choose between two Faital 3s or one and a PR I'd pick two active drivers. They will be louder and cleaner overall. PRs have their place. In my setup I want to use them in the pods because where they go active drivers don't fit, so the choice is two active two passive or just two active. In a door I would do passive radiator as well. I don't want two active drivers playing as a horizontal line array, that will sound bad. Adding PRs will just improve the low end sensitivity but keep the single point source. The choice here is between PRs and one active driver and just one active driver. 

In a trunk I wouldn't use PRs because I'd rather have 3 active drivers, more output no matter what. If I have room for a 12" PR I have room for a sub etc.


----------



## fish

Had to give you another thanks.  This is some good stuff I've been reading in this thread the past couple days. 

Strange how the PR doesn't really affect the 4"ers output (possibly because the active driver has more cone area than the PR?), but makes a very noticeable difference with the 3".

I see what you're saying about choosing active over a passive. 

Hopefully Erin & Patrick can get this Klippel issue sorted out shortly, & I can PM him about when would be a good time to send him the pair of 3FE20's for testing.

A little off-topic, setting output capability aside, what would you say are the most noticeable differences between your setup in your S2000 & Accord? I've resorted back to the craziness in your old build many times.


----------



## cvjoint

fish said:


> Had to give you another thanks.  This is some good stuff I've been reading in this thread the past couple days.
> 
> Strange how the PR doesn't really affect the 4"ers output (possibly because the active driver has more cone area than the PR?), but makes a very noticeable difference with the 3".
> 
> I see what you're saying about choosing active over a passive.
> 
> Hopefully Erin & Patrick can get this Klippel issue sorted out shortly, & I can PM him about when would be a good time to send him the pair of 3FE20's for testing.
> 
> A little off-topic, setting output capability aside, what would you say are the most noticeable differences between your setup in your S2000 & Accord? I've resorted back to the craziness in your old build many times.


Yep, you are right. I added 2 then 3 PRs and kept adding output 160hz and up. It still wouldn't reduce xmax much on the active driver like it did in the case of the 3. Modeling lots and lots of choices can really help pin down combination that works, especially with PR. There is no golden choice. 

Zaph is not getting back to me regarding the testing. I'll hold off on any changes if you got a pair laying around for testing. I'm very curious about how it tests. It's a bit of an oddball, pro audio in nature yet in a HI FI size. I wish it wasn't so rugged looking. Those exposed VC wires on the front of the cone are not as pretty to look at as say a Fountek. I generally don't care about looks enough to sacrifice output but this one will be in my face all day. Those passive radiators are sexy though, and dirt cheap. I wanna buy some just to look at them. 

Ahh, the Accord had lots of things going on. If I were to pick one, it has to be the 10" Excel Midbass drivers. The midbass is the weak link in EVERY car, it's ridiculously hard to get lots of output down to 63hz and keep it from frying or exceeding xmax. That setup did it for me, it sounded robust and healthy, 2,3 times it's size. Then the Excel while notoriously fickle, it was a thing of beauty. Every little part in those drivers is low resonance. The rubber surround was thin yet curvaceous, the Mg/Al hybrid cone was tougher, and deader than any cone I tried to flex, the voice coil was just big enough such as to reduce inductance, the basket had so much venting I could stick my hand and grab the coil. The magnesium Excels are one of the most fascinating speakers ever made, yet they cringe in a car, it requires calculated turns on the volume knob. 

The S2000 shines in the infinite baffle options. There are very few cars that allow a 3ft x 1 ft opening between you and the drivers. I can clearly say there are nuances in sub passages that get completely eaten away by seat cushions. I never believed in it until know. Everything vibrates with bass and creates it's own tune, with this car it's unadulterated. But then these doors could never house 10's without a complete redesign, and I mean it, total. Every door knob and rod would have to be re engineered. I could never afford to take out 2 months to build fiberglass doors again either.


----------



## BigRed

George, are u going to be trying 2 threes per side ?


----------



## fish

I really anxious to get these tested now. I'm gonna go ahead & contact Erin later today. 

I remember in our pm discussion recommending the SLS10 (depth pending) for midbass. How high did you play the XLS10's? That's really the only thing that concerns me is these Faitals play so well above 100hz. Again, trade-offs. 

So, did you already purchase the 4FR30's & TB PR's?


EDIT: These Faitals aren't too much on their looks, they're just raw. Especially compared to the Fountek's.


----------



## cvjoint

BigRed said:


> George, are u going to be trying 2 threes per side ?


I'm thinking either two 4" sealed or three 2.5" with 2 passive radiators. If I could replace the planars with some line array that can cross low say 200hz and still play as loud that would be great. 



fish said:


> I really anxious to get these tested now. I'm gonna go ahead & contact Erin later today.
> 
> I remember in our pm discussion recommending the SLS10 (depth pending) for midbass. How high did you play the XLS10's? That's really the only thing that concerns me is these Faitals play so well above 100hz. Again, trade-offs.
> 
> So, did you already purchase the 4FR30's & TB PR's?
> 
> 
> EDIT: These Faitals aren't too much on their looks, they're just raw. Especially compared to the Fountek's.


The Parts Express guy got back to me on the passive radiators, they are 1-1/16 inch deep. It will be a tight squeeze, gotta check it out. I didn't buy anything yet. Gotta make sure I pick the right setup before I butcher my pods again. 

I played the XXLS 10's only up to 125hz. I had 8" midranges taking it up from there. It looks like the frequency response is smooth up to 500hz. It can be crossed up to 250hz I would say. If the SLS gives you enough output I'd go with that for a midbass driver. The parts are lower resonance in a woofer than a subwoofer. The inductance will be smaller too due to the reduction in voice coil size.


----------



## fish

cvjoint said:


> The Parts Express guy got back to me on the passive radiators, they are 1-1/16 inch deep. It will be a tight squeeze, gotta check it out. I didn't buy anything yet. Gotta make sure I pick the right setup before I butcher my pods again.




That's sure is a lot better than the 2" mounting depth PE lists.


----------



## omegaslast

cvjoint said:


> Yep, you are right. I added 2 then 3 PRs and kept adding output 160hz and up. It still wouldn't reduce xmax much on the active driver like it did in the case of the 3. Modeling lots and lots of choices can really help pin down combination that works, especially with PR. There is no golden choice.
> 
> Zaph is not getting back to me regarding the testing. I'll hold off on any changes if you got a pair laying around for testing. I'm very curious about how it tests. It's a bit of an oddball, pro audio in nature yet in a HI FI size. I wish it wasn't so rugged looking. Those exposed VC wires on the front of the cone are not as pretty to look at as say a Fountek. I generally don't care about looks enough to sacrifice output but this one will be in my face all day. Those passive radiators are sexy though, and dirt cheap. I wanna buy some just to look at them.
> 
> Ahh, the Accord had lots of things going on. If I were to pick one, it has to be the 10" Excel Midbass drivers. The midbass is the weak link in EVERY car, it's ridiculously hard to get lots of output down to 63hz and keep it from frying or exceeding xmax. That setup did it for me, it sounded robust and healthy, 2,3 times it's size. Then the Excel while notoriously fickle, it was a thing of beauty. Every little part in those drivers is low resonance. The rubber surround was thin yet curvaceous, the Mg/Al hybrid cone was tougher, and deader than any cone I tried to flex, the voice coil was just big enough such as to reduce inductance, the basket had so much venting I could stick my hand and grab the coil. The magnesium Excels are one of the most fascinating speakers ever made, yet they cringe in a car, it requires calculated turns on the volume knob.
> 
> The S2000 shines in the infinite baffle options. There are very few cars that allow a 3ft x 1 ft opening between you and the drivers. I can clearly say there are nuances in sub passages that get completely eaten away by seat cushions. I never believed in it until know. Everything vibrates with bass and creates it's own tune, with this car it's unadulterated. But then these doors could never house 10's without a complete redesign, and I mean it, total. Every door knob and rod would have to be re engineered. I could never afford to take out 2 months to build fiberglass doors again either.


Zaph passed away due to cancer several months ago. There was a thread on audiokarma but i cant find it at this time.


----------



## cvjoint

I've been snooping around for ideas. The downsides to the passive radiators are enormous:
1. Midrange leakage
This is huge. Most passive radiators are used for subwoofer systems. If used with a midrange (extremely rare) the PR must be installed far away from the mid. 
2. 180 degree phase inversion at the tunning frequency. This makes matching the midbass down bellow a pain in the ass.
3. Group delay is all over the place. This I knew, but the effects are drastic in the much more audible midrange territory. 

My PRs would be right next to the driver. That's a very bad placement, and the midrange leakage alone makes this a futile exercise. 

So we are back to sealed. One trick with sealed boxes is to make an aperiodic vent. I could do this at the bottom of the pod so that it's not visible. This can increase the effective box size by 20% from what I could find. 

I'm leaning heavily towards the triple Peerless 2.5 widebanders. I could run these: 200hz-4,000hz with no comb filtering effect and only 3mm of excursion at the full 150watts. The box Q is 1.0, respectable for a midrange and that's before the aperiodic vent. Output is a whooping 109db. These will kill the dual Faital 3 combo in every way. 

The dual 4" Faital combo while louder has a much more restricted range: 250hz-3,000hz, and a Q of 1.15 which is way too high. On the bottom the output drops sharply because the box is too small, on the top the comb filtering effects are great. 

So the triple Peerless sealed is the preferred choice. Any problems with this one any one of you can see?


----------



## cvjoint

omegaslast said:


> Zaph passed away due to cancer several months ago. There was a thread on audiokarma but i cant find it at this time.


What? That is a heavy loss for our hobby. It explains the lack of email correspondence for sure. He will be missed.


----------



## DanMan

cvjoint said:


> What? That is a heavy loss for our hobby. It explains the lack of email correspondence for sure. He will be missed.


I don't think this is true. A guy named Zilch, I believe, passed away. If I am in fact wrong, I apologize.


----------



## cvjoint

DanMan said:


> I don't think this is true. A guy named Zilch, I believe, passed away. If I am in fact wrong, I apologize.


Ok, so I checked his blog. Last entry date: June 3rd 2011. He did not pass away months ago. Is Zilch "nothing/no one"? Are you guys messin' around?


----------



## omegaslast

Im an idiot, it was zilch. I got them confused, sorry about that.


----------



## SSSnake

Zilch was the econowave guy. I hate to hear he passed. 

CV,

I saw your post at work and was going to mention midrange leakage but didn't want to bring it up without pointing out links. Good luck with the array!


----------



## cvjoint

SSSnake said:


> Zilch was the econowave guy. I hate to hear he passed.
> 
> CV,
> 
> I saw your post at work and was going to mention midrange leakage but didn't want to bring it up without pointing out links. Good luck with the array!



Ahh, yeah. It's tough to find legit links about this stuff, nobody models it or tests for it. It's a very pertinent issue and simple once you think about it. 

I gave everybody thanks, was feeling good today.


----------



## pwnt by pat

I have four of those peerless 2.5's laying around if you're interested.


----------



## cvjoint

pwnt by pat said:


> I have four of those peerless 2.5's laying around if you're interested.


What's the millage on them? 

If I can't come up with a better setup I'll pull the trigger on some at the end of the week. 

I will probably need to find a place that can cut metal to make me a baffle. Anybody know where I can submit a sketch and get a machined piece back ready to bolt in?


----------



## pwnt by pat

Very low. I wasn't a fan so they went on the shelf.

For metal, call around your local automotive machine shops and see who has a waterjet. Won't be cheap, though. If you have a 4.5" grinder and some metal hole-saws you could do it yourself in no time.


----------



## cvjoint

pwnt by pat said:


> Very low. I wasn't a fan so they went on the shelf.
> 
> For metal, call around your local automotive machine shops and see who has a waterjet. Won't be cheap, though. If you have a 4.5" grinder and some metal hole-saws you could do it yourself in no time.


Not a fan? Do share. Are these 8 ohm btw?

Hmm, I can buy a hole-saw. I think my dad has a grinder too. Is that to cut metal straight line?



Time alignment is going to be a ***** with the line array. Actually you can't even use a stand alone processor, it requires separate amplifying. This is not good.


----------



## fish

cvjoint said:


> Time alignment is going to be a ***** with the line array. Actually you can't even use a stand alone processor, it requires separate amplifying. This is not good.




Well, that sucks to hear the bad news about the whole bag of issues that come along with using PR's... too good to be true I guess. 

How do you plan to overcome this problem with time aligning an array? Adjusting the gains of each one of the trio's individual amp's channels? Did that come out right? 

Oh, thanks for the thanks!


----------



## circa40

George, I have 4 of the 3" versions of the Peerless if you ever want to try them out.
https://www.madisound.com/store/product_info.php?manufacturers_id=143&products_id=8305


----------



## cvjoint

fish said:


> Well, that sucks to hear the bad news about the whole bag of issues that come along with using PR's... too good to be true I guess.
> 
> How do you plan to overcome this problem with time aligning an array? Adjusting the gains of each one of the trio's individual amp's channels? Did that come out right?
> 
> Oh, thanks for the thanks!


Damn, yet another problem. The output between three different drivers is well, going to be different. It's probably not enough to be able to adjust it in a DSP where the steps are 1db or more. The amp would have to have separate gains to do this right. 

Of course time alignment is not even enough to properly align speakers. Because our brain processes location by the time arrival difference between early and late reflections and the output difference between high and low frequency sounds, it will just be a band aid. 

Ok, so let's say you implemented all these steps (MS8 would work, 650 dollars and 10lb of extra weight later) what happens when you move your head from where you tuned it? In a single midrange scenario output and time alignment is fixed by default, one point source. The best you can do is use some DSP band aids which will all fail when you move your head anyway. 

The line array is starting to look as bad as the PR setup. The only feasible way I see this done is to buy a car with reverse oriented pillars. That, or you can be a midget. Heck, even that won't work, you'll probably sit on a booster seat and negate all the advantages of being short. 



circa40 said:


> George, I have 4 of the 3" versions of the Peerless if you ever want to try them out.
> https://www.madisound.com/store/product_info.php?manufacturers_id=143&products_id=8305


Ahh thanks Vin, I'll keep it in mind. I have the TB W3s if you want to play with small cones. I gots a bunch of tweeters too, sb29 and vifa xt25. Let me know, I can bring them to the meet.


----------



## fish

cvjoint said:


> Damn, yet another problem. The output between three different drivers is well, going to be different. It's probably not enough to be able to adjust it in a DSP where the steps are 1db or more. The amp would have to have separate gains to do this right.
> 
> Of course time alignment is not even enough to properly align speakers. Because our brain processes location by the time arrival difference between early and late reflections and the output difference between high and low frequency sounds, it will just be a band aid.
> 
> Ok, so let's say you implemented all these steps (MS8 would work, 650 dollars and 10lb of extra weight later) what happens when you move your head from where you tuned it? In a single midrange scenario output and time alignment is fixed by default, one point source. The best you can do is use some DSP band aids which will all fail when you move your head anyway.
> 
> The line array is starting to look as bad as the PR setup. The only feasible way I see this done is to buy a car with reverse oriented pillars. That, or you can be a midget. Heck, even that won't work, you'll probably sit on a booster seat and negate all the advantages of being short.



http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/331-pillar-line-array.html

I saw you posted in this thread that just seemed to die, unless lycan realized that amount of drivers (16/side) wasn't going to work. 

I KNOW you've modeled this driver Bohlender Graebener Neo10 Planar Transducer . Did it still have too sharp of a roll-off after about 400-500hz sealed?


----------



## cvjoint

fish said:


> http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/331-pillar-line-array.html
> 
> I saw you posted in this thread that just seemed to die, unless lycan realized that amount of drivers (16/side) wasn't going to work.
> 
> I KNOW you've modeled this driver Bohlender Graebener Neo10 Planar Transducer . Did it still have too sharp of a roll-off after about 400-500hz sealed?


I did not model the Neo10 or any BG planar for that matter. Nobody offers T/S parameters for them. By best guess is that they can't measure it since the impedance peak is minuscule. Zaph did however test it and the results are insane. Take any best options we've come up with so far, this thing will kill it in every way.

Usable frequency: 150hz-10,000hz
Sensitivity 1w/1m 92db, basically twice as loud per watt as our triple line array
Then of course it's a single speaker so no problems with time alignment, output matching, or comb filtering. 
Even better, THD is lower throughout than conventional speakers like domes or cones. 

However, they are monstrous and I can't get them to fit. But I can get the little brother, the Neo 8-S. 
Usable frequency: 200hz-10,000hz
Sensitivity 1w/1m 93db
It's a straight plug in replacement of the Neo 8.


To answer your question, all BG planars have a general rise in response. In the now old designs, Neo 8, Neo 8 pdr placing the planar a bit off axis would get you flat response over 1,000hz but still rising up to 1,000hz. That's basically why I never crossed the Neo 8 I have under 1000hz. That and the power handling goes down, distortion goes up. 

In these newer BG planars, the Neo 8-s, Neo 10 the response still has a general rise, but only over 1,000hz. So what does this mean? If you place them 30 degrees off axis you will get a flat response from 200hz (150 in the neo 10 case) to 10,000hz. Unlike the standard cone speakers you don't need more than 1/8 cube to seal them up. Lastly the memberane is way stronger than the older models, this will net not only higher sensitivity but higher power handling as well.


----------



## 96jimmyslt

> Let me know what you think


I think you should try to keep the car really nice and make it look as factory as possible.

Those 3 subs in the middle of the trunk?

I would suggest having 2 small 8"s or 10"s - one on each side, hidden and out of the way of any storage space

2 form fitting boxes on each side like this


hosting images


----------



## cvjoint

96jimmyslt said:


> I think you should try to keep the car really nice and make it look as factory as possible.
> 
> Those 3 subs in the middle of the trunk?
> 
> I would suggest having 2 small 8"s or 10"s - one on each side, hidden and out of the way of any storage space
> 
> 2 form fitting boxes on each side like this
> 
> 
> hosting images


Well, it doesn't look factory because I didn't hide the subs. I can make a beauty plate over them and cover it in carpet. That will make it look stock. I probably will soon, but I don't care enough, it's not like I drive with the trunk open. I do want some grilles on them.

What you recommend is the standard application for an s2000. People hide 8s or 10s in the side of the trunk. One problem with this approach is that it takes up MORE trunk space. My baffle takes virtually no room, if I were to take it off, that 3-6 inch opening is no good for storing stuff. That parts is closed of from factory and generally holds the spare. 

The second and more problematic thing is output. Two 10s sealed will pale in comparison to three 12"s in IB. Not only will they not reproduce the lowest frequencies loud enough they will be about 2 times lower in SPL. That of course means more distortion for any given output. 

Third problem is weight. Small sealed box subs weigh more, they need more motor to make do with less space. Then you have to enclose them completely, unlike my IB subs. Two tens in two small boxes sealed will weigh about 10lbs more. 

I sound like I'm resisting opinions at times but I really am not. I considered this option. No worky as well. Also, I don't know if it's just the way you drew it but the trunk won't close if the enclosure goes this far. The 10s would also need to be fairly shallow, which means even less output, make that 3 times less spl.


----------



## fish

cvjoint said:


> I did not model the Neo10 or any BG planar for that matter. Nobody offers T/S parameters for them. By best guess is that they can't measure it since the impedance peak is minuscule. Zaph did however test it and the results are insane. Take any best options we've come up with so far, this thing will kill it in every way.
> 
> Usable frequency: 150hz-10,000hz
> Sensitivity 1w/1m 92db, basically twice as loud per watt as our triple line array
> Then of course it's a single speaker so no problems with time alignment, output matching, or comb filtering.
> Even better, THD is lower throughout than conventional speakers like domes or cones.
> 
> However, they are monstrous and I can't get them to fit. But I can get the little brother, the Neo 8-S.
> Usable frequency: 200hz-10,000hz
> Sensitivity 1w/1m 93db
> It's a straight plug in replacement of the Neo 8.
> 
> 
> To answer your question, all BG planars have a general rise in response. In the now old designs, Neo 8, Neo 8 pdr placing the planar a bit off axis would get you flat response over 1,000hz but still rising up to 1,000hz. That's basically why I never crossed the Neo 8 I have under 1000hz. That and the power handling goes down, distortion goes up.
> 
> In these newer BG planars, the Neo 8-s, Neo 10 the response still has a general rise, but only over 1,000hz. So what does this mean? If you place them 30 degrees off axis you will get a flat response from 200hz (150 in the neo 10 case) to 10,000hz. Unlike the standard cone speakers you don't need more than 1/8 cube to seal them up. Lastly the memberane is way stronger than the older models, this will net not only higher sensitivity but higher power handling as well.



I thought about space requirements after I posted, but wasn't sure if they'd fit your pods or not. I saw your link to the new Neo8 a couple pages back. I'm gonna have to read up on these when I have some spare time.


----------



## circa40

cvjoint said:


> Ahh thanks Vin, I'll keep it in mind. I have the TB W3s if you want to play with small cones. I gots a bunch of tweeters too, sb29 and vifa xt25. Let me know, I can bring them to the meet.


Thanks for the offer, I'll keep that in mind. I've already fiddled with the W3s though...James Bang's mids. I'll bring the Peerless mids to the next meet


----------



## cvjoint

circa40 said:


> Thanks for the offer, I'll keep that in mind. I've already fiddled with the W3s though...James Bang's mids. I'll bring the Peerless mids to the next meet


you know what, ill try them. its not too hard to make a quarter inch baffle. as a matter of fact ill try them all. i can test every setup and post it here so we can compare distortion and such. well do peerless first then tb w3, then something else, dont know yet.

zaph got back to me, hes too busy right now for testing, what a shame.

i just saw a bg speaker that uses neo 8-s drivers. its crossed at 270hz. thats really nice.


----------



## cvjoint

I got 2x CSS SDX7, and 4x Faital Pro 4" coming in the mail soon!

I went crazy and also bought a WT3 speaker tester.


----------



## ErinH

cvjoint said:


> I went crazy and also bought a WT3 speaker tester.


a necessary tool for audio enthusiasts. smart purchase.


----------



## Brian Steele

bikinpunk said:


> a necessary tool for audio enthusiasts. smart purchase.


And it could be used for a lot more than just testing woofers too.


----------



## Brian Steele

cvjoint said:


> I got 2x CSS SDX7, and 4x Faital Pro 4" coming in the mail soon!


Are you replacing those 6.5" B&C drivers in the doors?


----------



## cvjoint

bikinpunk said:


> a necessary tool for audio enthusiasts. smart purchase.


Sure is! I was a bit pissed when I saw that I missed the $25 dollars off deal on them. But then I found an Amazon special where they bundle it with a scale. Shipping was a lot less than PE as well, $5 or so. Lastly, it's getting shipped from PE anyway. 



Brian Steele said:


> And it could be used for a lot more than just testing woofers too.


Yeah, I mostly want it to test QTC for my subs and now pillar mids. Ever since Erin told me about this opportunity I wanted one. 



Brian Steele said:


> Are you replacing those 6.5" B&C drivers in the doors?


Well, I hope so. Their duty is changing from 100hz - 1,600hz to 63hz - 200hz. The B&C was king over that range. In the new setup, the SDX7 models better. I really hope this CSS driver won't overheat with 180 watts on tap. I'll have to truncate the basket to get it in and then it's pretty much value less on the market. Not to mention no warranty. It better deliver!


----------



## ErinH

cvjoint said:


> Sure is! I was a bit pissed when I saw that I missed the $25 dollars off deal on them. But then I found an Amazon special where they bundle it with a scale. Shipping was a lot less than PE as well, $5 or so. Lastly, it's getting shipped from PE anyway.


it's weird.
sometimes buying from their store is cheaper than from their site. other times it's the other way around.


I almost exclusively use mine in the car for impedance sweeps in enclosures to find resonance.


----------



## bassfromspace

Have you considered sealed-back pro audio midranges in place of the neo 8?


----------



## cvjoint

bassfromspace said:


> Have you considered sealed-back pro audio midranges in place of the neo 8?


Didn't know they exist! A quick look at PE shows that most of these have ridiculous Qts. A 6.5" barely goes down to 450hz. That's the thing with extra small enclosures, there is no low end extension, and I need to go down to 200hz. 

Well it makes me feel good about the dual Faitals in my pods. The Qtc will be smaller than most of these and they can cross one octave lower. 

I can see this is a fantastic application for kicks. All you need is a baffle. Even there you may want more extension though.


----------



## bassfromspace

cvjoint said:


> Didn't know they exist! A quick look at PE shows that most of these have ridiculous Qts. A 6.5" barely goes down to 450hz. That's the thing with extra small enclosures, there is no low end extension, and I need to go down to 200hz.
> 
> Well it makes me feel good about the dual Faitals in my pods. The Qtc will be smaller than most of these and they can cross one octave lower.
> 
> I can see this is a fantastic application for kicks. All you need is a baffle. Even there you may want more extension though.


I wasn'r sure if you had a max cut-off, but you're right, they won't work as low.

I'm looking at these for a kicks application as well, mated with a horn or high efficicency planar, and also wondering about midbass/midrange integration issues.


----------



## cvjoint

bassfromspace said:


> I wasn'r sure if you had a max cut-off, but you're right, they won't work as low.
> 
> I'm looking at these for a kicks application as well, mated with a horn or high efficicency planar, and also wondering about midbass/midrange integration issues.


I was looking at 200hz. This should be tame enough not to segment the vocals too much if the mid and midbass are spaced far apart. Ideally you want to go down to 85hz, some male voices go down that low, but bellow 200hz our brains have a hard time figuring out where stuff comes from. I consider 200hz-1600hz the red zone for crossovers. Based on the studies I've read we are very good at findings things in the lateral plane at those frequencies. It makes sense too, considering evolution and survival skills on the ground. 

My setup is pillar-door. In a kick-door application the separation is not as bad, although I haven't ever crossed my kicks higher than 200hz. 

One other thing. In HT diyers are mad about absorbing the rear wave for mids such that it doesn't get reflected back through the cone. These mids forgo any rear wave reduction efforts. I wonder what the implications are. I would be able to absorb the entire rear wave 1000hz and above, but bellow my open cell foam is no good. At 200hz it's darn near useless. Maybe it's something you can EQ. I read that low end peaking can be EQd out too. Wonder if that's true. Resonance never sounded like music to me.


----------



## quality_sound

You can go a bit higher and not have separation issues. I've gone as high as 300Hz and only had a TINY bit of pull on the stage. With 250Hz I had no issues at all. Not that it's a huge difference from where you're at now, just something to try.


----------



## fish

cvjoint said:


> I got 2x CSS SDX7, and 4x Faital Pro 4" coming in the mail soon!
> 
> I went crazy and also bought a WT3 speaker tester.



You figured this was your best option out of all your choices? I hope it works out, & can't wait to see some graphs! 

Those sealed back mids looked appealing, but the very high Qts & crossover was a deal breaker.


----------



## cvjoint

fish said:


> You figured this was your best option out of all your choices? I hope it works out, & can't wait to see some graphs!
> 
> Those sealed back mids looked appealing, but the very high Qts & crossover was a deal breaker.


Well, my basic recipe has always been to get as much speaker cone surface area as possible out of the car and drop it in the biggest box possible. From what I can tell tricks like passive radiators and venting are a poor substitute for sealed or IB with lots of drivers or big drivers. The dual Faitals would be equivalent to dropping a 7" pro audio on the dash and that's just bad ass. 

The Peerless trio had the surface area of one 4" Faital and consequently the same sensitivity and output. One Faital does not have any of the problems associated with line arrays so it seems like the easy choice. If duals don't have severe comb effects or box resonance then it's even better than one. I would also think that since they are so close to each other I may get away with not having separate TA and gain over them. With three drivers this would be more problematic. The Peerless also have a Q of .7. That tells me they are made for open baffles, something that's not feasible in a car.


----------



## fish

I agree, having that much cone area up on the dash is pretty exciting. I've just been staring at my pillars for the last couple weeks trying to figure out a way to get dual 4's plus a tweet up there. It's not looking too promising. 

If there is noticeable combing effects with the dual 4's is a single Faital 4" option #2?


----------



## cvjoint

fish said:


> I agree, having that much cone area up on the dash is pretty exciting. I've just been staring at my pillars for the last couple weeks trying to figure out a way to get dual 4's plus a tweet up there. It's not looking too promising.
> 
> If there is noticeable combing effects with the dual 4's is a single Faital 4" option #2?


The Faitals are amazing at requiring the smallest possible mounting area. The drawback is that the baffle has to be very precise. It is noticeably smaller than most 4" but packs the same surface area. 

Yeah, I'm going to try them single and dual. I can also try the TB WT3 and Vin's Peerless mids. Should be a fun summer. If all fails I'll drop the cash for the Neo 8-S, it just makes more sense in my application than the regular Neo8. Lots of options, I'll just into it open to accept whichever tests and sounds better.


----------



## cvjoint

Enter the SDX7, XBL2, we meet again. 










Ordered them on Sunday from the Canadian firm. Got them in the mail earlier today or earlier in the week, don't know when but QUICK!

Now for the not so good parts. The box they were shipped in was tiny. Little packing. Crappy packing. The surround on both speakers is crumpled a bit. Not sure how the heck they are assembling them together but it's sloppy. 














































First thoughts. 

Bad:
Tinsel leads are tiny. The TB 3" widebanders have the same gauge wire. 
The crumpled surround.

Good:
No tinsel slap at high excursion.
Virtually inexistent motor noise, the back is exquisitely vented like I've never seen before.
The spider is massive, same diameter as the cone. 
The surround I'm split on, it seems smallish for 11mm xmax but still larger than other 7"s. Maybe the SlS has a nicer surround.
Light!
Sounds superb full range.
The carbon fiber and copper phaseplug are delight to look at. 
Gargantuan excursion. I tried to videotape it but my phone can't keep up with it.


----------



## fish

Those are really nice looking speakers. Too bad about the bad packing job, bad for business. As far as the crumpled surround, is what you're talking about in the second pic (with your hand in it) where the light hits the cone/surround?


----------



## fish

Those are really nice looking speakers. Too bad about the bad packing job, bad for business. As far as the crumpled surround, is what you're talking about in the second pic (with your hand in it) where the light hits the cone/surround?


----------



## cvjoint

Yeah that's the one. It looks like someone manhandled it to get it glued.


----------



## cvjoint

Yeah that's the one. It looks like someone manhandled it to get it glued.


----------



## circa40

Are those going in your doors? I was seriously thinking about use a pair for my kicks. 
Hurry and install them, I want to listen


----------



## SSSnake

CV,

Please do a comparison between these and the B&Cs. I hvae been considering jumping back into the HE world and I am interested if these will provide the same pop.

BTW - the faitals are *nice* speakers. Depending on passbands they may more than make up for swapping over to a lower efficiency midbass.


----------



## cvjoint

Weird stuff is happening with the forum. The last post I see here is mine, but the search engine says SSSnake lol


----------



## fish

cvjoint said:


> Weird stuff is happening with the forum. The last post I see here is mine, but the search engine says SSSnake lol



I tried to get into this thread earlier, but as soon as I started to scroll down the screen would jump back up to the top immediately. Did that about 15 times, then I gave up. 

If you can't see SSSnake's post above yours, he's asked you to compare the B&C & the SDX-7 (I think). BTW, I'm curious what kind of "sound" would you characterize the B&C having?


----------



## cvjoint

Is the whole post I wrote just gone?

Yeah, it is. Damn, this forum is breaking down. 

The install time depends on Erin. If he wants to test these on the Klippel it may take a while.


----------



## cvjoint

From now on there will be a full review every week of a new speaker install. First, the title for the best fullrange/wideband driver will be disputed. Second, the title for the best 7" midbass driver. 

Here's what I had in mind:
*TS parameters free air
*TS parameters in car
*Frequency response in car no EQ.
*Frequency response in car EQ. flat
*THD test

Based on the tests we can give each driver a rating for usable passband and distortion. I can give mild subjective reviews but that's not my forte. For the usable passband I'm thinking -3db points on top and bottom. For the distortion test I'm thinking 95db and 100db tests at 1m on the passband that it is derived. 

Any input on what tests to do? 

This week I will test the incumbent: BG Neo 8.


----------



## cvjoint

*BG Neo 8 Evaluation*

T/S parameters free air left 
* f(s)= 343.90 Hz
* R(e)= 3.46 Ohms
* Z(max)= 3.69 Ohms
* Q(ms)= 3.221
* Q(es)= 47.160
* Q(ts)= 3.015
* L(e)= 0.00 mH

T/S parameters in-car left
* f(s)= 362.70 Hz
* R(e)= 4.13 Ohms
* Z(max)= 4.24 Ohms
* Q(ms)= 3.153
* Q(es)= 116.700
* Q(ts)= 3.070
* L(e)= 0.00 mH

T/S parameters free air right
* f(s)= 321.70 Hz
* R(e)= 3.60 Ohms
* Z(max)= 3.82 Ohms
* Q(ms)= 2.951
* Q(es)= 47.980
* Q(ts)= 2.780
* L(e)= 0.00 mH

T/S parameters in-car right
* f(s)= 324.30 Hz
* R(e)= 3.88 Ohms
* Z(max)= 4.00 Ohms
* Q(ms)= 2.558
* Q(es)= 78.400
* Q(ts)= 2.477
* L(e)= 0.00 mH

Take these parameter tests with caution, the Neo 8s have such a small impedance peak the WT3 barely knows it's testing anything. I've never seen parameters published on these guys so I figured for curiosity's sake I'll post them. 

Next the money tests. 

Frequency response is tested as follows. I use a HP 24db slope at 200hz to mimic the application needs here, a mid that can cover 200hz-6,000hz. There is no LP filter. With a proper HP in place I can test at high SPL. The test is of the right speaker since that is the farthest so it will play the loudest once I equalize the gains for left and right. It's roughly 1 meter away, like in standard tests. No EQ. is used, just the one crossover at 200hz. 

FR at 90db (volume 36 on my deck):










HD at 95db










HD at 100db










HD at 105db










*Thoughts*

The FR looks great 1.25khz all the way to 13khz or so. Crossing down to 200hz however seems very problematic. There is a big dip in response between 350hz and 1.25khz. It seems to me that the speaker starts rolling off at 1.25khz naturally. The reason why it picks up again down low is because of the low end peaking. Just look at the tested QTS, it's enormous. Once we get another speaker in there we'll know for sure if it's the car environment or the speaker that creates that large dip.

*Until then I'm going to rate this speaker as 800hz - 14,500hz based on -3db points. * This corresponds somewhat to 2x FS, so the rule of thumb would work too. 

HD @ 95db is great. The highest distortion point is 800hz with 3.5% THD. Note that if you want to EQ. up this frequency to flatten the FR the distortion here would get worse. Everywhere else this speaker is 1% or under. 

HD @100db seems to be a mirror image of the lower output test. I then decided to test it at +5db. 

HD @105db a little bit more distortion this time. 3.5% at 300hz and about 5% at 800hz. Everywhere else 1% or bellow still! It seems the worst points for THD are 300hz, 800hz, 1600hz. 

It seems that from both a linear and nonlinear distortion view this speaker should be crossed 800hz and up. If used as such it gets insanely loud and clear. Crossing bellow 800hz brings lots of headaches. 

Next I will test a 3" widebander. We'll get a taste for what conventional technology can do and get a feel for what this car's reflections are like.


----------



## omegaslast

Interesting stuff. I have LS-6s with 6 NEO-8s on each side 

Danny richie designed them, hes a big fan of B&G drivers. He crosses over the neo8 at 1khz to 6.5" peerless drivers. They really arent full range drivers, theyre just drivers that can be crossed a lot lower than any tweeter out there, while at the same reaching pretty high. I think 1khz keeps the crossover out of most of the vocals, while not forcing the neo-8s to produce a lot of bass. Id just make sure to get a fairly efficient 6.5" woofer to pair up with in a car


----------



## bassfromspace

cvjoint said:


> *BG Neo 8 Evaluation*
> 
> T/S parameters free air left
> * f(s)= 343.90 Hz
> * R(e)= 3.46 Ohms
> * Z(max)= 3.69 Ohms
> * Q(ms)= 3.221
> * Q(es)= 47.160
> * Q(ts)= 3.015
> * L(e)= 0.00 mH
> 
> T/S parameters in-car left
> * f(s)= 362.70 Hz
> * R(e)= 4.13 Ohms
> * Z(max)= 4.24 Ohms
> * Q(ms)= 3.153
> * Q(es)= 116.700
> * Q(ts)= 3.070
> * L(e)= 0.00 mH
> 
> T/S parameters free air right
> * f(s)= 321.70 Hz
> * R(e)= 3.60 Ohms
> * Z(max)= 3.82 Ohms
> * Q(ms)= 2.951
> * Q(es)= 47.980
> * Q(ts)= 2.780
> * L(e)= 0.00 mH
> 
> T/S parameters in-car right
> * f(s)= 324.30 Hz
> * R(e)= 3.88 Ohms
> * Z(max)= 4.00 Ohms
> * Q(ms)= 2.558
> * Q(es)= 78.400
> * Q(ts)= 2.477
> * L(e)= 0.00 mH
> 
> Take these parameter tests with caution, the Neo 8s have such a small impedance peak the WT3 barely knows it's testing anything. I've never seen parameters published on these guys so I figured for curiosity's sake I'll post them.
> 
> Next the money tests.
> 
> Frequency response is tested as follows. I use a HP 24db slope at 200hz to mimic the application needs here, a mid that can cover 200hz-6,000hz. There is no LP filter. With a proper HP in place I can test at high SPL. The test is of the right speaker since that is the farthest so it will play the loudest once I equalize the gains for left and right. It's roughly 1 meter away, like in standard tests. No EQ. is used, just the one crossover at 200hz.
> 
> FR at 90db (volume 36 on my deck):
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> HD at 95db
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> HD at 100db
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> HD at 105db
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> *Thoughts*
> 
> The FR looks great 1.25khz all the way to 13khz or so. Crossing down to 200hz however seems very problematic. There is a big dip in response between 350hz and 1.25khz. It seems to me that the speaker starts rolling off at 1.25khz naturally. The reason why it picks up again down low is because of the low end peaking. Just look at the tested QTS, it's enormous. Once we get another speaker in there we'll know for sure if it's the car environment or the speaker that creates that large dip.
> 
> *Until then I'm going to rate this speaker as 800hz - 14,500hz based on -3db points. * This corresponds somewhat to 2x FS, so the rule of thumb would work too.
> 
> HD @ 95db is great. The highest distortion point is 800hz with 3.5% THD. Note that if you want to EQ. up this frequency to flatten the FR the distortion here would get worse. Everywhere else this speaker is 1% or under.
> 
> HD @100db seems to be a mirror image of the lower output test. I then decided to test it at +5db.
> 
> HD @105db a little bit more distortion this time. 3.5% at 300hz and about 5% at 800hz. Everywhere else 1% or bellow still! It seems the worst points for THD are 300hz, 800hz, 1600hz.
> 
> It seems that from both a linear and nonlinear distortion view this speaker should be crossed 800hz and up. If used as such it gets insanely loud and clear. Crossing bellow 800hz brings lots of headaches.
> 
> Next I will test a 3" widebander. We'll get a taste for what conventional technology can do and get a feel for what this car's reflections are like.


I agree with your conclusion of an 800hz HP based on my own usage.


----------



## cvjoint

omegaslast said:


> Interesting stuff. I have LS-6s with 6 NEO-8s on each side
> 
> Danny richie designed them, hes a big fan of B&G drivers. He crosses over the neo8 at 1khz to 6.5" peerless drivers. They really arent full range drivers, theyre just drivers that can be crossed a lot lower than any tweeter out there, while at the same reaching pretty high. I think 1khz keeps the crossover out of most of the vocals, while not forcing the neo-8s to produce a lot of bass. Id just make sure to get a fairly efficient 6.5" woofer to pair up with in a car


Is that the Danny from GR Research? He claims he can bring the Neo 8-S to the stateside if he wants to. Imo, he should. The S model crosses a whole octave lower on both sides. I would always use a tweeter up top anyway, the low crossover point would be nice. I guess he can use the Neo10 in HT, I just can't fit that thing in a car pillar. 

I'm not sure I buy a lot of the crossover points. If you really want to not chop up vocals use one driver over 85hz-6,000hz. You might get away with 200hz-5,000hz. Slicing anywhere 400hz-1,600hz seems like the meat of the midrange to me. That's also where ITDs are very useful for localization. I'd think some of these xover points used in speakers are based on other factors like flattening out the FR without the need for EQ.


----------



## cvjoint

*Peerless PLS-P830986 3" Fullrange Evaluation*

T/S parameters free air left 
* f(s)= 103.60 Hz
* R(e)= 6.26 Ohms
* Z(max)= 46.04 Ohms
* Q(ms)= 5.513
* Q(es)= 0.868
* Q(ts)= 0.750
* L(e)= 0.13 mH

T/S parameters in-car left
* f(s)= 133.20 Hz
* R(e)= 7.35 Ohms
* Z(max)= 18.30 Ohms
* Q(ms)= 1.695
* Q(es)= 1.138
* Q(ts)= 0.681
* L(e)= 0.14 mH

T/S parameters free air right
* f(s)= 103.60 Hz
* R(e)= 6.24 Ohms
* Z(max)= 44.93 Ohms
* Q(ms)= 5.108
* Q(es)= 0.823
* Q(ts)= 0.709
* L(e)= 0.13 mH

T/S parameters in-car right
* f(s)= 110.40 Hz
* R(e)= 7.18 Ohms
* Z(max)= 19.38 Ohms
* Q(ms)= 1.527
* Q(es)= 0.899
* Q(ts)= 0.566
* L(e)= 0.14 mH

Note: in-car tests were done without more that 10 min left for cooling. The impedance curves are also somewhat irregular. The right pillar pod is however bigger and you can see this in the readings. 


FR at 90db Neo 8, 84db Peerless (volume 36 on my deck)
Red: Peerless, scaled up 6 db for comparison purposes
Black: Neo 8 










HD at 95db










HD at 100db










HD at 105db










*Thoughts*

We judged the Neo 8 knowing that the car interior might play a role. It did, significantly. The whole valley 300hz to 1.25khz is actually the installation/car interior. This is easy to see once you plot the two together. There are two stark differences in the FR between the two. First, bellow 300hz the Peerless has a rising response or at least flat whereas the planar rolls off. The Peerless has a breakup peak at 12khz. This is present as a ripple in the impedance curve as well. The Peerless is more extended, it can reach 20khz with a bit of eq. at 16khz. Peak at 20khz seems to be due to breakup induced modes from earlier on. The Neo 8 drops like a rock by 20khz. 

Based on FR alone the usable band now is:
*250hz - 14,500hz for the Neo 8, <200hz - 20,000hz for the Peerless based on -3db points. * 

HD @ 95db Excellent! this speaker is 1% or under. 

HD @100db Great, 2% or lower. 

HD @105db 4% in the low midrange over a wide band. This one does not have local problem peaks like the Neo 8. Two octaves above the HP are pretty dirty, overall more distortion than the Neo 8. 



Based on usable bandwidth the Peerless is the winner. The Neo 8 is whopping 6db more sensitive but 60watts is bound to be enough to get to 105db in a car with the Peerless. THD favors the Neo8. The planar gives better dynamics and requires less power for doing so. In turn it doesn't extend as low or as high as the cone driver. 

BTW, I'm really impressed with the high tech in the Peerless. I suspect this little guy is a monster of a 3" among the competition. It has everything one could hope for in a cone speaker, copper rings, lots of surface area/mounting requirements, strong neo motor, very well vented, beefy spider and suspension. This is likely to perform a bit better than my TB w3 that's going in next. However the basket is still plastic so you have to be very gentle with it. That's the only place they saved money. 

*Subjective Review*
I played a bunch of music on it before testing it. I though it sounded small and kinda average. The Neo 8 didn't impress me either crossed at 200hz. 

After I performed the testing above and realized my car is creating that wide dip I EQ.'d it severely. From 300hz to 1.25khz I added between 5-8db, I cut 12khz by 8 db where the breakup is, and boosted 16khz by 5db. This gave me a very flat FR 200hz-20khz. 

The next listening session was far far better. At low output it was a bit hard to tell the difference between my old setup and this. I will never underestimate the power of EQ. ever again. Truth is I think I can get this and the Neo 8 +B&C crossed at 1,6khz to sound the same under 100db. At higher output this one gets a bit of edge to it, signaling the end of the road. 

Three options for further testing:
Try TB 3"
Peerless 3" line array
Faital 4" 

The last test in this category will be a line array of the Faital 4". 

Pictures next.


----------



## circa40

George,
Its pretty of interesting that both the Neo8 and Peerless has simular response curves. 

Did you ever get a chance to test the Peerless in an open back enclosure? They had nice bottom end extension when I used them a few years ago in that configuration.

Were you able to test the T/S on both the new and old drivers? Im curious how much they changed (if any) after use. 

Thanks for the measurements man, they're pretty darn impressive IMHO


----------



## cvjoint

circa40 said:


> George,
> Its pretty of interesting that both the Neo8 and Peerless has simular response curves.
> 
> Did you ever get a chance to test the Peerless in an open back enclosure? They had nice bottom end extension when I used them a few years ago in that configuration.
> 
> Were you able to test the T/S on both the new and old drivers? Im curious how much they changed (if any) after use.
> 
> Thanks for the measurements man, they're pretty darn impressive IMHO


To test them open baffle I would need a large plywood piece and just install it in the middle. 

I haven't tested the newer drivers. There is a bit of variation from driver to driver from factory. I find this can be larger than new vs. broken in driver. Not sure you could tell much from the comparison. I also don't test VAS as you know. 

The bottom end is surprising even in the sealed pods. No problem whatsover to get down to 200hz.


----------



## thehatedguy

<- running 3 SDX7s in the front of his car and loving them. All of my surrounds are wrinkled like that. They each have a channel of a JL HD600/4 on them.


----------



## cvjoint

thehatedguy said:


> <- running 3 SDX7s in the front of his car and loving them. All of my surrounds are wrinkled like that. They each have a channel of a JL HD600/4 on them.


Well, at least I know that's the usual look. I kinda figured since both were like that. I would have emailed them if it was just one. No chances they'll care to make them neat. The HT guys must be pissed when they see them. Mine are going in doors so I don't care. 

I imagine you have a center?


----------



## fish

Thanks George, good stuff. Did the Peerless test better than you had thought?


----------



## cvjoint

fish said:


> Thanks George, good stuff. Did the Peerless test better than you had thought?


I suppose it did. I'm still not a big fan of small cones. At high output it's clear they distort quite a bit. Having 200hz and up on my dash is new to me and sounds great staging wise. I was listening some more today in the drive through at low levels and the precision with which instruments can be located on the stage is amazing. 

Now, the second I got out of the drive through I turned it up a bit and was quite disappointed at how shouty it got. At times there is a clear pop and crack from the little guy. 

At low levels the Peerless sounds flat and unadulterated. It's never exciting, but never irritating either. I wonder if this is how reference sound should be.

The planars are spectacular at making every recording sound special, and unlike ribbons they never get irritating. I still can't put my finger on what makes the BG planars sound so good. I want the cone frequency response with the planar sound. If it's just surface area I can get that with dual 4s. But then there are all the promises of planar technology, no glue, no spider, just a freely vibrating element. Is this stuff just marketing? is there nothing I can test to figure out what it is about the planars? 

Another big difference is the reverberation. Now that I constrained the 7"s to only go up to 200hz instead of 1,600hz the cabin doesn't get filled the same way. There is less spaciousness, but accuracy has improved. The frequency response is also impervious to leg and torso movements, virtually no shift can be detected.


----------



## thehatedguy

Yes sir, MS-8 system with the center.

I was looking at the B&Gs also. Maybe I should give them a try sometime.


----------



## cvjoint

B&C came out with a killer 5.25" driver too. It should work great for people who want to chop up their dash for a mid or the Honda Fit guys with lots of room up top.


----------



## fish

cvjoint said:


> I suppose it did. I'm still not a big fan of small cones. At high output it's clear they distort quite a bit. Having 200hz and up on my dash is new to me and sounds great staging wise. I was listening some more today in the drive through at low levels and the precision with which instruments can be located on the stage is amazing.
> 
> Now, the second I got out of the drive through I turned it up a bit and was quite disappointed at how shouty it got. At times there is a clear pop and crack from the little guy.
> 
> At low levels the Peerless sounds flat and unadulterated. It's never exciting, but never irritating either. I wonder if this is how reference sound should be.
> 
> The planars are spectacular at making every recording sound special, and unlike ribbons they never get irritating. I still can't put my finger on what makes the BG planars sound so good. I want the cone frequency response with the planar sound. If it's just surface area I can get that with dual 4s. But then there are all the promises of planar technology, no glue, no spider, just a freely vibrating element. Is this stuff just marketing? is there nothing I can test to figure out what it is about the planars?
> 
> Another big difference is the reverberation. Now that I constrained the 7"s to only go up to 200hz instead of 1,600hz the cabin doesn't get filled the same way. There is less spaciousness, but accuracy has improved. The frequency response is also impervious to leg and torso movements, virtually no shift can be detected.



There it goes with those trade-offs again.  I'm with you, I've grown used to having 250hz & up on the dash, & am worried if I change up to a mid in the kicks I'll lose that high, accurate stage. 

In order to get a little more ooomph up on the dash I bought a pair of these from a forum member Tang Band W4-1337SD 4" Titanium Driver. Since I posted that link I have to comment on TB's recent price hike on their drivers, that has nearly doubled in price!  WTF are they thinking? 

I've been waiting for those B&C 5" mids to come out for a while now. That'd be a pretty easy kick install. According to a B&C rep I emailed, they were supposed to be for sale @ PE by the end of May. Did you find them somewhere that says they're actually in-stock?


----------



## vactor

fish said:


> There it goes with those trade-offs again.  I'm with you, I've grown used to having 250hz & up on the dash, & am worried if I change up to a mid in the kicks I'll lose that high, accurate stage.
> 
> I've been waiting for those B&C 5" mids to come out for a while now. That'd be a pretty easy kick install. According to a B&C rep I emailed, they were supposed to be for sale @ PE by the end of May. Did you find them somewhere that says they're actually in-stock?


i have never had a problem with stage height doing kicks (mids and tweeters) and have had 4 of them in the past. i have not heard a soundstage as good as with kicks as compared to ANY other setup.


----------



## fish

vactor said:


> i have never had a problem with stage height doing kicks (mids and tweeters) and have had 4 of them in the past. i have not heard a soundstage as good as with kicks as compared to ANY other setup.



What vehicle(s) did you have success in? In my Civic, my left leg is usually in one of two positions. One of them is with my foot on or against the dead pedal.


----------



## cvjoint

fish said:


> There it goes with those trade-offs again.  I'm with you, I've grown used to having 250hz & up on the dash, & am worried if I change up to a mid in the kicks I'll lose that high, accurate stage.
> 
> In order to get a little more ooomph up on the dash I bought a pair of these from a forum member Tang Band W4-1337SD 4" Titanium Driver. Since I posted that link I have to comment on TB's recent price hike on their drivers, that has nearly doubled in price!  WTF are they thinking?
> 
> I've been waiting for those B&C 5" mids to come out for a while now. That'd be a pretty easy kick install. According to a B&C rep I emailed, they were supposed to be for sale @ PE by the end of May. Did you find them somewhere that says they're actually in-stock?


I didn't try to buy them or anything. I imagine they'll get them produced soon. 

With kicks the largest tradeoff to me is not stage height. The variance you get in frequency response is the killer. I could test it for you with my leg sitting just so and no passenger and it would test great, especially if you can fit a larger woofer than the pillars. The problem is with a passenger the majority of the right signal is blocked. On the left I move my legs a lot too. Covering any speaker other than a sub is bound to bring about the worst. 

TBs are getting lots of recognition now, and Chinese labor in general is getting more expensive. I think they've engineered more stuff in the last 2 years than most companies have done in a lifetime. Lots of original ideas to boot.


----------



## cvjoint

fish said:


> What vehicle(s) did you have success in? In my Civic, my left leg is usually in one of two positions. One of them is with my foot on or against the dead pedal.


Get a Fit! They have those extended pillars with the side glass. You can easily fit your 5" B&C in there and lay smack on everybody. I told Circa40 the same thing. Heck you can probably fit the 7", port it, and cross it 63hz - 5,000hz. 110db flat FR the whole way. I'm saying this because they are similar cars to me, FF and economical. If you have the SI or Type R I would understand.


----------



## fish

cvjoint said:


> Get a Fit! They have those extended pillars with the side glass. You can easily fit your 5" B&C in there and lay smack on everybody. I told Circa40 the same thing. Heck you can probably fit the 7", port it, and cross it 63hz - 5,000hz. 110db flat FR the whole way. I'm saying this because they are similar cars to me, FF and economical. If you have the SI or Type R I would understand.



If I could do it all over again I would put speaker placement in a car as a top priority, but when I got my '03 Civic I had no clue DIYMA existed.  If I had an 8th gen Civic I'd be set with those side windows.

The only passenger I have is my fiancee, & if I asked nicely she'd move her legs out of the speaker's path. 

What do you think about those TB W4-1337's I posted a link to? Had you ever considered those?


----------



## cvjoint

fish said:


> If I could do it all over again I would put speaker placement in a car as a top priority, but when I got my '03 Civic I had no clue DIYMA existed.  If I had an 8th gen Civic I'd be set with those side windows.
> 
> The only passenger I have is my fiancee, & if I asked nicely she'd move her legs out of the speaker's path.
> 
> What do you think about those TB W4-1337's I posted a link to? Had you ever considered those?


The only 4" that fits is the Faital. It's less than 4" wide whereas most 4"s are a bit over 4". The TB looks nice, the titanium is geared to be the better offering from TB from what I can tell.


----------



## quality_sound

What about the RS100? That's BARELY a 4" driver.


----------



## cvjoint

quality_sound said:


> What about the RS100? That's BARELY a 4" driver.


SD 37.4cm2
Faital Pro 4" SD 64cm2

That's a huge difference. Phase plugs in small cone drivers are futile imo. The reason why these drivers have such little use in a car is the low sensitivity. The phase plug sacrifices even more moving cone area. So what does it amount to? 6.5 db sensitivity difference. That's huge. The Faital is also shallower and uses a neo motor. The Faital just owns all in output density. The Dayton is more like an oversize 3" imo, not even 3.5". 

The only thing that scares me about the Faital is that it has no inductance treatment that I know of. I mean it's low, I tested it at less than .2mh, much lower than the Dayton, but is is LE symmetric over X? Does anybody know a quick test I can do with the WT3 to get inductance variance?


----------



## cvjoint

Images of installs so far.

The incumbent is the Neo 8:










Made some 1/4" MDF baffles that have the same bolt pattern as the Neo 8, and painted them black. This way I can go back to the Neo 8 is I want to. 



















First contender, the Peerless 3" solo:


----------



## thehatedguy

Damn it...don't make me want to buy Neo 8s to replace my pairs of Whispers.


----------



## AndyInOC

I've been wanting a set of Faital 4's since starting my rebuild, looking forward to reading your thoughts and maybe even get a chance to hear them in person sometime (depending on meets/schedules/life of course)


----------



## fish

AndyInOC said:


> I've been wanting a set of Faital 4's since starting my rebuild, looking forward to reading your thoughts and maybe even get a chance to hear them in person sometime (depending on meets/schedules/life of course)



No doubt! They're so shallow, & don't have much of a mounting flange to them either. I do hope they turn out well, which reminds me George, did the Faitals get sent to Erin yet?


----------



## cvjoint

Erin was busy so I only sent him the CSS drivers. I wish he got to test the Faitals too. 

These 3"s sure don't have any dynamics. I'm now thinking even two of them in a line array is really weaksauce. The thing is, once I EQ. in 8db or so throughout the midband they got no headroom left. I'll see if I can test it after EQ., it should look ridiculous. For now it's seriously putting a damper on my listening style. 

I might skip messing with threes and go to the Faitals. My only concern is that the Faitals are so large I can't go back to BG planars and clear the mounting holes. Decisions decisions.


----------



## cvjoint

AndyInOC said:


> I've been wanting a set of Faital 4's since starting my rebuild, looking forward to reading your thoughts and maybe even get a chance to hear them in person sometime (depending on meets/schedules/life of course)


There is some sort of meet/comp in July. Try to make it to that one. I won't compete but will come to say hi and test cars if anybody is down for it. 

My guess is the Faitals will kick ass and take names. These mids mean business.


----------



## cvjoint

I tuned the Peerless fullrange drivers a bit. I cut 1.25khz to 5khz, 200hz, 250hz, and 12khz. I only boosted at 16khz to help the driver extend high. Since most of the tunning was cuts I had to raise the overall gain on the fullrange when I was done. 

Here's the new tune in red ( blended with midbass and sub) vs. no EQ. in black. 










Here is what THD looks like after tunning at 100db:










Again two full octaves of over 1% distortion. My guess is that it's easily noticeable since it spans such a wide range 300hz to about 1200hz. Luckily I had to cut 200hz rather than boost, that's where most of the distortion would be usually, right next to the HP filter. 

I might get the Faital in tomorrow.


----------



## cvjoint

*Faital Pro 4" Fullrange*











FR at 90db Neo 8, 91db Faital (volume 36 on my deck)
Red: Faital
Black: Neo 8 










HD at 95db










HD at 100db










HD at 105db










*Thoughts*

Interesting! This driver can keep up with the Neo8 in the distortion, FR, and sensitivity. It's not really a fullrange, even the Neo8 is a quasy fullrange driver. None of them extent up all that well. The Peerless is a better driver for that. With enough EQ. I got them to extend to about 18khz but that's really pushing the limits of my DSP. 

Out of the box the Faital sounded a bit annoying. It turns out it has somewhat of a breakup well within the audible range, at 8khz. Once I tamed it things got fun really fast. This driver can be crossed under 200hz fairly easily. At 200hz is barely breaking a sweat. Basically, the Faital can be crossed lower than the Neo8. In turn it doesn't extend as high. The passband gets shifted towards the lows. 

Based on FR alone (-3db) the usable band is:
*<200hz - 12,500hz * 

HD @ 95db Excellent! this speaker is 1% or under. 

HD @100db Excellent! Just like the Neo8, almost no change 95db to 100db.

HD @105db 2% in the low midrange over a wide band. Hard to sum up the comparison with the Neo8 now. Over 2000hz the BG planar is cleaner than this. Bellow 2000hz these are more or less tied. 

A note on sensitivity:
We haven't yet taken into account the impedance of these drivers. I'm going to use the Peerless as a benchmark because their specs are usually dead on. 

Peerless *83db 1w/1m*
Bg Neo 8 *86db 1w/1m*
Faital Pro 4" *90db 1w/1m*

90db 1w/1m is outstanding for a 4". Count in that the overall diameter is less than 4". Diyers have been looking for a dedicated small midrange for car use for years. This is it imo. 

The planar is arguably overrated sensitivity wise. It falls way short of the 90db 1w/1m rating. Because it handles power really well it still slightly edges the Faital in THD, but it's really splitting hairs between the two.


----------



## fish

Nice post! This is REALLY good news! 

I had my doubts about it's use as a full range driver without a tweeter, but I'm over that.


----------



## 60ndown

have you measured the road noise in DB with the top down @ 70 mph yet ?

I'd guess its going to be in the 110db range @ 500hz.

90 DB with the top up

if you only want to enjoy music while parked your doing fine

but if you want to bump @ 70 mph with the top down your going to need to rethink your plans.

imj.


----------



## cvjoint

60ndown said:


> have you measured the road noise in DB with the top down @ 70 mph yet ?
> 
> I'd guess its going to be in the 110db range @ 500hz.
> 
> 90 DB with the top up
> 
> if you only want to enjoy music while parked your doing fine
> 
> but if you want to bump @ 70 mph with the top down your going to need to rethink your plans.
> 
> imj.


Not yet, I need to have somebody drive it for these type of tests. 

The difference between windows down and top down is not that much, but yeah over 100db roadnoise. 

I did all I could to make this car loud. I'm open to suggestions. You should preach this on the S2000 forums. These guys think a 10" sealed is more than enough for the car. 

Ultimately, having the open sky is worth a little bit of background noise. And if the noise comes from the engine even better.


----------



## cvjoint

Update on the search for a 7" midbass driver:

CSS Klippel results are up. In reality it seems the CSS has no more stroke than my B&C ~ 4mm. The 8" B&C tested at a clean 5mm xmax, I figure the 7" will test at similar limits or maybe 1mm lower at 4mm. Factor in the sensitivity of the B&C and there is no way the CSS can edge it out in anything. 

I checked all the Klippel results so far we have on 7" speakers. This includes a wide range, Peerless HDS, Scan Revelator, Seas Excel, Hertz Mille, Pioneer Prs, Adire Extremis, Rainbow Reference and a couple of others. Out of the pack only two speakers seem to have more xmax than a B&C: Adire Extremis and Hertz Mille. The Extremis is discontinued so no luck there. The Hertz is crazy expensive. The Hertz is very sensitive, on top with the B&C but cannot handle power as well. Neither of the two have a truncated basket so I would have to butcher them to make them fit. 

Three drivers out there could have more extension than the B&C that haven't been Klippel tested to my knowledge, the Exodus, AE 7", and SLS. The first two are way to deep. The SLS seems like the one out there that may be feasible. Until I see a Klippel on it the B&C stays.

Oh yeah, one more thing. With the exception of one 7", most xmax ratings are suspension limited. It seems like there are plenty of great motors out there but few suspensions that can keep up with them. Again, the SLS looks more appealing given that gargantuan surround.


----------



## ncv6coupe

Cant beat all these raw data measurements here. Thanks for posting everything up. Good choice on the B&C staying put until further notice. Would be great if you put them up in the fenders! hint hint wink wink


----------



## cvjoint

ncv6coupe said:


> Cant beat all these raw data measurements here. Thanks for posting everything up. Good choice on the B&C staying put until further notice. Would be great if you put them up in the fenders! hint hint wink wink


Ahh yeah, the fenders. there is a 3 inch square cut out behind the kickpanels. If anybody is willing to cut a bit more and relocate the main wire harnesses the midbasses could be relocated there. Since this chassis is designed for performance and I do race it once or twice a year I'd rather not chop it up. I don't want to compromise any of the chassis stiffness. A bit less stage depth is fine with me. 

Here is a bit more info on the Faital since I managed to get the WT2 working on Windows 7:










Note the impedance anomaly at 3,000hz. This shows up in my HD tests above as well. Initially I thought it may background noise but it is not. Even the peak at 8,000hz in the FR corresponds to a disruption in the impedance curve. If anybody has a clue on what this could be spit it out.


----------



## cvjoint

Grew some cojones and tested the Faital at 110db!










Distortion is at 5% in the lower midrange but the simple fact that it's still alive and kicking is amazing. That's of course one 4" driver playing 200hz and up. Now we have something to compare with when I add the second Faital in a line array. I also took a 1/24 smoothed FR so we can see if comb filtering appears when stacked. 

I fully tuned the car using the Faitals 200hz to 6,3khz, so pure midrange duty. They sound fantastic. Really makes me double think my line array ideas since there is loads of output. It still not as airy as the planars but they sound more robust. To me it's a draw between the Neo8 and the Pro 4". I could live with either and spend hours in the car simply admiring the performance.


----------



## quality_sound

cvjoint said:


> SD 37.4cm2
> Faital Pro 4" SD 64cm2
> 
> That's a huge difference. Phase plugs in small cone drivers are futile imo. The reason why these drivers have such little use in a car is the low sensitivity. The phase plug sacrifices even more moving cone area. So what does it amount to? 6.5 db sensitivity difference. That's huge. The Faital is also shallower and uses a neo motor. The Faital just owns all in output density. The Dayton is more like an oversize 3" imo, not even 3.5".
> 
> The only thing that scares me about the Faital is that it has no inductance treatment that I know of. I mean it's low, I tested it at less than .2mh, much lower than the Dayton, but is is LE symmetric over X? Does anybody know a quick test I can do with the WT3 to get inductance variance?


Does it really give up that much cone area? I suggested it because it's definitely small, but I didn't think it was THAT much smaller.


----------



## cvjoint

When you see the funky a$$ basket on these Faitals you realize how they pull it off. Daytons on the otherhand always seem to have a large basket. I guess they are meant for home audio so it matters little there.


----------



## fish

That notch @ 3k shows up in the FR & impedance graph on Faital's site also. IIRC, the 3"er's follow the same trend @ 3k. You mentioned the breakup @ 8k, was the one @ 3k as noticeable?

Mark Brooks listened to the 3" back when he was trying out a bunch of small widebanders, and told me he thought it was "shouty". What frequency range is considered shouty?


----------



## subwoofery

fish said:


> That notch @ 3k shows up in the FR & impedance graph on Faital's site also. IIRC, the 3"er's follow the same trend @ 3k. You mentioned the breakup @ 8k, was the one @ 3k as noticeable?
> 
> Mark Brooks listened to the 3" back when he was trying out a bunch of small widebanders, and told me he thought it was "shouty". What frequency range is considered shouty?


Shouty is in the upper midrange. 
I'd say between 4kHz and 6kHz (perhaps up to 9kHz). 

Kelvin


----------



## cvjoint

fish said:


> That notch @ 3k shows up in the FR & impedance graph on Faital's site also. IIRC, the 3"er's follow the same trend @ 3k. You mentioned the breakup @ 8k, was the one @ 3k as noticeable?
> 
> Mark Brooks listened to the 3" back when he was trying out a bunch of small widebanders, and told me he thought it was "shouty". What frequency range is considered shouty?


Who knows what "shouty" is. It may be different from person to person. The peak at 8khz is most likely a frequency response anomaly only. Once EQ.'d out it sounds just fine to me. If there is any THD associated with it it's outside of our listening abilities anyway. New studies emphasize the importance of low frequency distortion even more. 

To me the breakup is more than a worthy tradeoff. It something you can EQ. out and in return you get very low distortion in the low midrange where it counts. It seems well designed imo, if you can concentrate the peak in one spot you should move it as far outside of the audible band as possible. Anybody using this as a pure midrange is going to have no problem with it. 

The 3khz peak in the THD is probably noticeable at high output but not at low to medium. I can't tell you how it sounds but it's all second order so shouldn't be too bad. You can EQ. out 3db at 3,000hz and get rid of most I would think at little cost to the FR. 

The most noticeable distortion in this driver, just like any small cone is going to be low midrange. This one is bound to sound better than any of the heavy, small cone HiFi competitors. 

It's probably safe to say that the "big speaker" "laid back" sound of PA drivers is low THD. This Faital proves it, in that it's a tiny speaker with big sound. I can't wait to get the line array going.


----------



## bassfromspace

What size enclosue are using for the faital vs. the BG?


----------



## 60ndown

Trunkate a 5" mid 

personally if i had a car i knew i was going to own and drive for a year or 2, i wouldnt hesitate to buy some midrange drivers that were a little too big, and grind the edge of the basket/frame so it was narrower, 

you might be able to get a bigger cone driver in there if your good and careful with a grinder/file?


id do it to a pair of $500 drivers if i knew was going to enjoy them for a couple years 


like this, but the midrange

Dayton Audio DC28FT-8 1-1/8" Silk Dome Truncated Tweeter


lots of edge to lose

https://www.madisound.com/store/product_info.php?cPath=45_234_266&products_id=1315


----------



## cvjoint

bassfromspace said:


> What size enclosue are using for the faital vs. the BG?


Same pods. The passenger side one is probably around 120 in3.



60ndown said:


> Trunkate a 5" mid
> 
> personally if i had a car i knew i was going to own and drive for a year or 2, i wouldnt hesitate to buy some midrange drivers that were a little too big, and grind the edge of the basket/frame so it was narrower,
> 
> you might be able to get a bigger cone driver in there if your good and careful with a grinder/file?
> 
> 
> id do it to a pair of $500 drivers if i knew was going to enjoy them for a couple years
> 
> 
> like this, but the midrange
> 
> Dayton Audio DC28FT-8 1-1/8" Silk Dome Truncated Tweeter
> 
> 
> lots of edge to lose
> 
> https://www.madisound.com/store/product_info.php?cPath=45_234_266&products_id=1315


I wouldn't mind truncating some speakers to get more options. For the midbass this is definitely a requirement, I was set to do it on the CSS if they tested nicer. 

There are two restrictions:

-Some mounting hole patterns don't allow truncation
-Cutout still has to be under 4", 93mm tops so it gets enough edge to mount on.


----------



## 60ndown

i also wouldnt hesitate to trunkate a magnet not sure how id get it done, but id try 

i built a set of speakers for a friend of mine recently, with these,

http://www.creativesound.ca/details.php?model=EL70


very nice sound.


----------



## cvjoint

60ndown said:


> i also wouldnt hesitate to trunkate a magnet not sure how id get it done, but id try
> 
> i built a set of speakers for a friend of mine recently, with these,
> 
> Creative Sound - Product Details
> 
> 
> very nice sound.


Don't get crazy, leave the magnets alone!

Interesting on how much info they have on that CSS. I wonder how much of it makes a legitimate difference. Zaph tested some of Mark's speakers I think.


----------



## 60ndown

cvjoint said:


> Interesting on how much info they have on that CSS. I wonder how much of it makes a legitimate difference. Zaph tested some of Mark's speakers I think.


only $80 a pair, buy some to test,

if you dont like them you can easily get your money back.


----------



## cvjoint

60ndown said:


> only $80 a pair, buy some to test,
> 
> if you dont like them you can easily get your money back.


They won't fit,even truncated, nor do they promise a whole lot: 5 db less sensitive is a lot. I'll try something that can topple the Faital. There really isn't anything out there.


----------



## 60ndown

cvjoint said:


> They won't fit,even truncated, nor do they promise a whole lot: 5 db less sensitive is a lot. I'll try something that can topple the Faital. There really isn't anything out there.


Faital Pro 4FE30 4" Speakers - Faital Pro 4FE30 mid-high speaker has a wide frequency range from 90Hz to 20kHz and has a lightweight neodymium magnet - Faital Pro 4FE30 60 watt 3" has an efficiency of 91dB SPL for all high quality mid-high applicatio

after using these for the last year

Galaxy Audio S5N-8 5" Neodymium Full Range Driver 8 Ohm

i know where your going, but im starting to wonder (after a year listening to them) if a speaker that is designed from the ground up to be an esss queee driver, that can also get quite loud,

isnt a better choice then

a loud speaker.


full range pro audio drivers get loud and can sound good.


essque drivers sound like heaven all the time on everything.


----------



## cvjoint

It's hard to make hard statements about Pro Audio and HI Fi drivers in general. Some things do hold all the time, for the same size speaker the PA driver will always have less power compression. It used to be the HIFI driver always had more Xmax but times are changing. B&C, 18 Sound, and Faital all make some compromise speakers with generous xmax but lower sensitivity. I would just look at speakers individually not manufacturers or PA vs. HiFi anymore. 

Look at the 7" category on Zaph Audio, a long time HiFi strong hold. That 18sound mid is walking all over the HIFI drivers. At higher output I bet the ownage is even more severe. 

I spent some time on this graph but hopefully it paints a better picture than I could put in words. If we put the two, PA and HIFI together, on average this is what we would find:










Up to 80db the HiFi is lower distortion, but it's all bellow audible thresholds. The PA driver will sound better just about everywhere else, where it does matter.


----------



## 60ndown

im not sure a graph or tests will actually reveal how a driver sounds in real life?

i might be wrong, 

but actually spending some time listening to drivers that have been 'broken in' (or trusting the opinion of other people with good ears) would be a much better way for me to determine if i like the way they sound,

or not.


----------



## cvjoint

60ndown said:


> im not sure a graph or tests will actually reveal how a driver sounds in real life?
> 
> i might be wrong,
> 
> but actually spending some time listening to drivers that have been 'broken in' (or trusting the opinion of other people with good ears) would be a much better way for me to determine if i like the way they sound,
> 
> or not.


Only one way to find out. Buy the equipment, understand it, use it. Then go back to reading golden-ear prose and see how useful it is. If they are blindly converging on a wrong theory you wouldn't even know. It wouldn't be the first, the world was flat at one point. Armed with instruments at least you are slowly gaining more and more knowledge, converging on the truth. At some point you'll have to make your own equipment to advance in understanding but that's a far point to most.


----------



## BigRed

George, where do u think your ears can hear a difference in distortion ? 1.5 to 2.5%? Just curious. I know you weigh some of your decisions based on distortion. Have u ever tested 2 drivers. One with great sensitivity and another less efficient and played them with the same amplitude and frequency response via eq and could point out distortion? I think that would be a cool test.


----------



## cvjoint

BigRed said:


> George, where do u think your ears can hear a difference in distortion ? 1.5 to 2.5%? Just curious. I know you weigh some of your decisions based on distortion. Have u ever tested 2 drivers. One with great sensitivity and another less efficient and played them with the same amplitude and frequency response via eq and could point out distortion? I think that would be a cool test.


I took the Klippel tests online a couple of times. The first time it was on my Sony over the ear headphones MDR V600 is the model no. I think. I could only get it ~ 9%, and I thought that was a bit odd. 

Next I took the same tests with my Etymotic I6 in the ear headphones and I could reliably pick up distortion down to 1.7%. 

Based on those results I can at least hear distortion at 1.7%. That is however an upper bound. Maybe I can hear under 1.7% if I can test myself with a perfect set of test headphones. Some studies show some folks pick up distortion down to .8%. Even on the Klippel site there are a few. Practically I just go with 1% as the threshold for distortion. Music has a masking effect too and I believe .8% is all with test tones. 

Equally important is where the distortion takes place. Is THD 1% at 12,000hz? It's not really audible there even at 50%. Bass, low midrange is key I think as it propagates into very bothersome frequency ranges. Also third vs. second order etc. 


I did perform a test like that here. Look at the Peerless vs. Faital at any given SPL level. The Peerless is low sensitivity the Faital is high sensitivity. The Faital has lower THD throughout the midrange. I think most of it comes from the larger cone. In turn the Peerless is better in the top octave if you don't have a tweeter. Smaller cone means beaming gets moved into higher frequencies.


----------



## cvjoint

Line array is in! How does it sound? Like a million bucks!! Eating, then testing them tonight.


----------



## fish

Standing by....


----------



## cvjoint

First some pictures.

This was the *single Faital Pro 4"* on the test baffle. I mounted it right next to the tweeter. This way I can still use the baffle for the line array. It just so happened it helped staging too since it was at ear level and closer to the tweeter and therefore a better point source.










*Pods modified to fit duals*:










Once I'm done with the test baffle they can mount right on the pod for an even more stealth look. 

For now on the test baffle they are. *Line Array!*:










The paper cone treatment gives them quite a bit of shine for a paper cone. I was coming down from the top of the parking structure and I kept staring at how gorgeous they are as the parking structure lights illuminate the cones. 

Phone camera doesn't do it justice but:











*FR Faital Array vs. Neo 8* as I did for the rest, vol 36 on the head. They are getting 90w @ 4 ohm in parallel just like the Neo 8:










Total ownage over the planar. Anywhere from 3db to 17db more output up to 12khz. 

*FR Faital Array vs. Faital Single*










Similar ownage. Theory predicts 6db gain when mounted in a line array at 1m. I get anywhere from 2 to 12db more. Maybe the extra gain in low frequencies is due to coupling and the loss up top is due to comb filtering, I don't know. 

Talking about comb filtering, when I had the single mounted I took a pic of the FR at higher resolution just to see if comb filtering could exist at *1/24 octave smoothing* but not at 1/6 octave like I usually test. The ear is generally believed to hear sounds as if 1/3 octave smoothed. Unsmoothed looked too nasty to even overlap imo. 

From the overlap above it seems that even if comb filtering exists it is not audible. In this graph I can't even see a trace of it at 1/24 octave smoothing. I'm not going to be worried about it and cross wherever. For now I'm ok with 6.3khz. 










Also on this topic, the *mic SPL level was right at 6db* more than the single, just as predicted. 

Next, THD tests.


----------



## cvjoint

*THD @95db:*









*THD @100db:*









*THD @105db:*









*THD @110db:*









Heck, more! That's a single pillar pod crossed down to 200hz!

*THD @115db:*










*95db* Excelent! 
*100db* Excelent! Most of it under .3%!
*105db* Excelent! All under 1%.
*110db* Some problem areas begin to appear, 2% distortion at 200hz and 630hz. At 200hz the distortion is probably motor induced from the need for higher excursion. The 630hz is probably my car acoustics. Note that the 3000hz problem area we saw before is there but still under 1%. The rest is under 1% as well. 
*115db* Under 3%, amazing. It was so loud it started being annoying even with ear plugs on. 


The discussions we had about pro audio vs. Hi Fi sparked an interest into distortion at "low" output. Even at 100db in a car these guys had on average .3% distortion. There is nothing that tells me these are compromised drivers for esque. I don't see HiFi drivers as a major competitor to these guys, as far as I can tell they can only lose the beauty contest. Those voice coil leads coming through the cone are not pretty but perhaps it's a bullet proof way of insuring against tinsel slap. It's pure badass.  In fact I'm surprised the protection ring they have going around the surround doesn't mess up the frequency response too much. 


The only challenger remains the BG planars imo. There is still something that the planars could do better. Maybe it was the flatter impedance, in-existent LE or quick decay. The impact was more clean cut. If I could fit whatever I wanted:

BG Neo10 > BG Neo 8-S = Faital line array > BG Neo 8 = Faital 4" single

I'll rock these for some time. They are definitely the most robust option for crossing low.


----------



## 60ndown

results look excellent, 

if i were you id make a few spare baffles, you have the technique and tools now.

you can run the faitals for 6 months until you find another driver that *might* work,

then when you feel motivated and you already have the baffles its a relatively quick change out. 

id want some kind of cover over the drivers in case some thief sees them and tears the car up trying to steal your audio (stealth = you keep them)

nice work, hard to believe you could get 2x4" drivers and a tweet in that A pillar


----------



## BigRed

Does it image the same? Size and stage placement?

Looks cool. Looking forward to hearing it soon


----------



## cvjoint

I'll keep the baffles for other candidates. I wish they made Seas Excels that fit, it would be nice to test these against THE reference. 

The imaging is very similar to the singles. Maybe not as focused but more grandiose. I'll take big sound anyday, sounds meaty!

So I was worried that this driver may have a no inductance treatment. I wasn't worried about the BL too much since the sensitivity is more than enough to offset it. I was also expecting the suspension to be tame since it's a pro audio driver. I emailed Faital to get more info on whether they use shorting rings. You probably know by now how I pick at all drivers for weakest link. 

Long story short Faital emailed me right before I went to bed (Italy time!)....

the Klippel report!!!

Coming up!

Yeah, it's good. Very good.


----------



## fish

Damn George, you're on top of ****! Your results look fantastic, & I can't wait to see the Klippel.

And you're right, those bland looking speakers look soooo much better with that paper coating on them. Where would one find some of that located locally?


----------



## 60ndown

cvjoint said:


> I'll keep the baffles for other candidates. .


other future candidates might be a different size/shape, having some spare blank baffles would be ideal.


----------



## fish

60ndown
after using these for the last year
[url=http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-020 said:


> Galaxy Audio S5N-8 5" Neodymium Full Range Driver 8 Ohm[/url]


60... how do you like those Galaxies? What frequency band are they playing?


----------



## vactor

make me some baffles for my s2k  same color even :O


----------



## cvjoint

fish said:


> Damn George, you're on top of ****! Your results look fantastic, & I can't wait to see the Klippel.
> 
> And you're right, those bland looking speakers look soooo much better with that paper coating on them. Where would one find some of that located locally?


I remember guys asking John at AE what he uses. Not sure he ever gave them an answer. I think this type of information is a secret of the trade. 



vactor said:


> make me some baffles for my s2k  same color even :O


You probably want the pods not just the mdf bafles haha. I figured out the best way to mount them without modifying the car at all. After several bad techniques, this one really rocks, not my pic:










Bend the tabs and push them into the original mounting holes for the stock a-pillar trim piece. Found them at ACE. Works better than other designs. 

*Klippel time!*

Faital 4fe30 4" Klippel
http://www.mediafire.com/?k8k6k7oqjphkqii

Faital 4fe30 4" T/S 
http://www.mediafire.com/?f1afxt5sck0lff6

1.8mm Xmax. The motor and suspension show perfect centering. There is an obvious effort to curb inductance, and it works. Inductance is also very low for a 4". There is lots of suspension throw, very unusual for a pro audio driver. Looks like a much much more expensive driver. 

For comparison purposes, some xmax figures from Erin's tests:
Peerless HDS 8" 2.2mm Sensitivity 88.5db
Dayton RS 100-8 2.3mm Sensitivity 82.5db
Hat 4" 2.4mm Sensitivity 84.8db
CSS SDX 7" 4mm Sensitivity 83.7db

With over 90db sensitivity and a generous amount of xmax this is a real killer setup. Can't really ask for more at $40, at $100. Not really sure how they manage to get them out so cheap.


----------



## 60ndown

fish said:


> 60... how do you like those Galaxies? What frequency band are they playing?


i have an audio control 3 way active x over, i can mix and match the x over points between midbass-midrange and tweets easily, and i have, many times over the last year or so.

id have said they were awesome up until about 6 weeks ago when i made a pair of speakers for a friend with these

Creative Sound - Product Details

im not certain if it was because it was in a room and not in a vehicle, but i think i heard the difference between a speaker that does everything well, and a speaker that does everything with AWESOMENESS.(think of a great looking woman (galaxy) then think of the most beautiful woman you've ever seen dancing naked in the moonlight wanting to bed you (el70) )




the only way to know for sure would be for me to put some el70s in ma whip. 

ive demoed many very 'high end ' ($20,000 audio only) vehicles over the years, so i kinda feel like i know what im listening for.

the galaxies have been in my whip for over a year, i play every kind of music, and sometimes i get pretty damn loud, 

they are still in there, thats a sure sign i like em and i havent killed them.


----------



## cubdenno

George,

How do you think the Faitel 4" would mate with the BG Neo 3?

I love that tweeter and am looking for a decent mid to mate with it that can match it's sensitivity.


----------



## bassfromspace

cubdenno said:


> George,
> 
> How do you think the Faitel 4" would mate with the BG Neo 3?
> 
> I love that tweeter and am looking for a decent mid to mate with it that can match it's sensitivity.


Damn good question.


----------



## cvjoint

Well, the Faital 4" can reach up to 12khz no problem. The best tweeter you can get is one that has a good power response up top, sensitive, and handles lots of power. I'm a big fan of the new 3/4" Vifa line. They are sensitive, handle lots of power, and they are enclosed so you can throw them in the Faital box. The 3/4" size gives them the good power response. Distortion performance is not important when picking a tweeter for the Faital (we can't hear harmonics over 10khz, that's why you don't see them in my THD graphs), not that the Vifas would suck or anything, they are 90% Scan Speak revelator in design goodies.

I've used three BG neo8s in my cars but never the 3. It just doesn't extend much higher than the neo8. Might as well get the 8 and cross lower and have even lower distortion. 

For the Faital you need a tiny tweeter that gets lots of output up top. Any big coil 3/4 domes will do. I wouldn't use ring radiators, ribbons or planars as top extension off axis is their weakness. I know some guys will tell you yeah, but right on axis planars, ribbons or ring radiators are great. I am 5 degrees of axis and I struggled to get the Vifa RR to extend to 18khz, same with my LCY ribbons, same with the neo 3 in my friend's car. Besides, you are going to move your head when you drive.

Neo 3 is a great compromise driver imo for people crossing low. That's where it kicks dome, ribbon, RR and other planars's asses. If you don't want to cross low there are better tweeters that won't compromise top octave extension.


----------



## vactor

so ... does that mean you will make me some pods like yours for my yellow S2k??  you know you want to ...


----------



## cvjoint

vactor said:


> so ... does that mean you will make me some pods like yours for my yellow S2k??  you know you want to ...


Fiberglass is the love of my life. It also slowly kills my lungs. 

I'll do any audio work for a Kraftwerks supercharger. Fair deal? 

Were you the dude asking about kickpanel installs? S2ki only knows prefab 10" sub boxes and the occasional double din chop the dash install. Don't dare ask anything else, they will set you up for public flogging over there.


----------



## vactor

yeah, too many kids with too much money and too little common sense, or any sense. ah well, the internet gives a voice to all


----------



## cvjoint

I think I'm on to something. In the BG neo8 vs Faitality Array I'm missing the decay, the third dimension:

"The Third Dimension
So far we've talked about frequency (the X axis of the graph) and amplitude (Y axis) but we left out an important third dimension: time. When a speaker responds to an impulse, for example a rim shot -- "THWACK!" -- it should start instantly and stop the instant the instrument stops making sound. If the speaker keeps vibrating or resonating and making sound after the source sound stops it's changing, or "coloring," the sound of the original recording. And that's bad.
Figure F	Figure G
Upload	Upload

Figure F shows a bandwidth limited impulse signal. You can see that it starts and stops abruptly. Figure G shows that same impulse coming out of a speaker. You can see that the sound persists after the impulse input has stopped -- it resonates or "rings." The speaker is changing the timbre or character of the original recording. In order to see to what extent and at which frequencies the "ringing" is happening, we use a sophisticated computer algorithm called MLLSA (affectionately called "Melissa" by engineers who don't date much) to measure the response of a speaker in frequency, amplitude and time. Figure H is a MLLSA spectral decay graph of a prototype speaker. The third axis of this graph is time, so graph lines closest to you are measurements taken later than the ones in the back. Think of it as a series of slices with each slice being a frequency response graph taken at a different point in time.

If we were to measure the perfect speaker the MLLSA graph would look like a straight line in back with no lines in front. Real speakers fall far short of this ideal and continue to resonate after an impulse has stopped, such as in Figure H. Figure I is a Polk LSi9, and we can see that the speaker stops responding sooner in the midrange than the speaker pictured in Figure H, indicating that the LSi9 is a better sounding speaker.
Figure H	Figure I
Upload	Upload

While no measurement technique can fully describe the subjective sound of a louds peaker, MLLSA and other frequency response measurements are of great help to Polk engineers in developing better sounding speakers. Only a fool would design a speaker based on measurements alone and only a total fool would design a speaker based solely on subjective listening. A speaker that might sound good on a particular recording may in fact be flawed - it may have what is commonly called a "euphonic coloration." It may be pleasing to the ear under certain conditions, but it sure ain't right."

See figs and more here: Understanding Speaker Frequency Response - eCoustics.com


I would think the planar has much better decay than a conventional cone. I think that's what gives it the "airy" nature. I can of course test this. I have the ability to produce Cumulative Spectrum Decay tests. Sadly enough I didn't do one for the BG Neo8 while it was in there. I now have to make a new baffle to test them again.


----------



## 24th-Alchemist

> When a speaker responds to an impulse, for example a rim shot -- "THWACK!" -- it should start instantly and stop the instant the instrument stops making sound. If the speaker keeps vibrating or resonating and making sound after the source sound stops it's changing, or "coloring," the sound of the original recording. And that's bad.


Suppose a speaker "keeps vibrating or resonating" when it shouldn't. Wouldn't those resonances show up as peaks in the FR curve?

There is a one-to-one relationship between impulse response and frequency response; therefore I'd like to better understand any additional interpretations that are made by looking at frequency energy across different segments in time. In a perfectly linear speaker, I can't see how _any_ additional information can be gleaned from a MLLSA: for example, if a speaker resonates, it will show as a FR peak. (Someone show me my totalitarian statement about linear speakers is wrong). In a non-linear system (as most speakers are I guess), I could see how something such as resonances could be time-limited or periodic themselves, and therefore be partially masked in a FR plot. But then the question arises, can any meaningful interpretations that relate to perceived sound be determined from the MLLSS (that aren't already available form the FR curve)?

For example, is there an MLLSA plot that has meets these two criterion:
(1) it shows a slow decay over some frequency range, and
(2) in the FR magnitude plot there is no increase at those same frequencies?

Whether the answer is yes, no or maybe, what does it mean; how can it be explained? And how can it be interpreted to give some insight into the perception of how the speaker sounds?


----------



## fish

cvjoint said:


> I did not model the Neo10 or any BG planar for that matter. Nobody offers T/S parameters for them. By best guess is that they can't measure it since the impedance peak is minuscule. Zaph did however test it and the results are insane. Take any best options we've come up with so far, this thing will kill it in every way.
> 
> Usable frequency: 150hz-10,000hz
> Sensitivity 1w/1m 92db, basically twice as loud per watt as our triple line array
> Then of course it's a single speaker so no problems with time alignment, output matching, or comb filtering.
> Even better, THD is lower throughout than conventional speakers like domes or cones.
> 
> However, they are monstrous and I can't get them to fit. But I can get the little brother, the Neo 8-S.
> Usable frequency: 200hz-10,000hz
> Sensitivity 1w/1m 93db
> It's a straight plug in replacement of the Neo 8.
> 
> 
> To answer your question, all BG planars have a general rise in response. In the now old designs, Neo 8, Neo 8 pdr placing the planar a bit off axis would get you flat response over 1,000hz but still rising up to 1,000hz. That's basically why I never crossed the Neo 8 I have under 1000hz. That and the power handling goes down, distortion goes up.
> 
> In these newer BG planars, the Neo 8-s, Neo 10 the response still has a general rise, but only over 1,000hz. So what does this mean? If you place them 30 degrees off axis you will get a flat response from 200hz (150 in the neo 10 case) to 10,000hz. Unlike the standard cone speakers you don't need more than 1/8 cube to seal them up. Lastly the memberane is way stronger than the older models, this will net not only higher sensitivity but higher power handling as well.


Going back a few pages... say you don't have 2-4 liters of space available along your a-pillars to make a sealed enclosure for the Neo8-S or Neo10 (if the Neo10 is applicable)? What are some other enclosure options? Would these not work aperiodic, since the proper way to get the vent right is by checking the change in impedance in the driver?


----------



## cvjoint

24th-Alchemist said:


> Suppose a speaker "keeps vibrating or resonating" when it shouldn't. Wouldn't those resonances show up as peaks in the FR curve?
> 
> There is a one-to-one relationship between impulse response and frequency response; therefore I'd like to better understand any additional interpretations that are made by looking at frequency energy across different segments in time. In a perfectly linear speaker, I can't see how _any_ additional information can be gleaned from a MLLSA: for example, if a speaker resonates, it will show as a FR peak. (Someone show me my totalitarian statement about linear speakers is wrong). In a non-linear system (as most speakers are I guess), I could see how something such as resonances could be time-limited or periodic themselves, and therefore be partially masked in a FR plot. But then the question arises, can any meaningful interpretations that relate to perceived sound be determined from the MLLSS (that aren't already available form the FR curve)?
> 
> For example, is there an MLLSA plot that has meets these two criterion:
> (1) it shows a slow decay over some frequency range, and
> (2) in the FR magnitude plot there is no increase at those same frequencies?
> 
> Whether the answer is yes, no or maybe, what does it mean; how can it be explained? And how can it be interpreted to give some insight into the perception of how the speaker sounds?


Thank you much for this response. The relationship between frequency response, CSD, and impulse response has long been an interest and a mystery to me. I am forewarning you that I'm very much a pupil on this subject. 

Let me see if I can come up with a counterexample to your theory that may bring brownie points for a CSD graph.

1.MLLSA graph number one has perfect decay and a perfectly flat response. Think unobtanium speaker here.

2.MLLSA graph number two also has perfect flat response, but also displays a perfect flat delay on the order of 1 ms for all frequencies.

Take both speakers above and test the frequency response only. The FR will look perfectly flat for both speakers (it will tell you both are perfect). In reality the CSD plot will tell you speaker 1. is in fact better. Speaker two has an equal "ringing" at all frequencies. When summed up in an FR graph this "third dimension" is lost. 

IF planars have less ringing at all frequencies, this intrinsic benefit of planar technology would be ...lost in translation in an FR graph would it not?


----------



## cvjoint

fish said:


> Going back a few pages... say you don't have 2-4 liters of space available along your a-pillars to make a sealed enclosure for the Neo8-S or Neo10 (if the Neo10 is applicable)? What are some other enclosure options? Would these not work aperiodic, since the proper way to get the vent right is by checking the change in impedance in the driver?


People say at times that their midrange is free air in a car. Imo, free air cannot be in a car because:
1. too little room
2. baffle isn't large enough to separate front and rear waves 

So the only thing that is left is a box. Sealed or aperiodic are good choices. You may not be able to get the proper T/S parameters for a planar but that doesn't mean you can't design a proper aperiodic enclosure for it. For example, you can test a small 2" cone driver on a test baffle to tune the enclosure. From the tests you can deduce the "extra airspace" gained by the aperiodic memberane. Drop in BG planar. Done. 

FWIW, I've also been unable to test Qtc properly with 2+ drivers so far. There are multimple impediance peaks that throw off the measurements. Lots of other things throw off measurements too, like leaks in the pods. I've managed to get one good smooth impedance plot for the driver side pod with the Faital but I still ran into problems. The impedance peak did not align with the QTC predicted in WinISD simulations. Which one to trust? The peak, and infer the QTC? The QTC and infer the peak? Are they both right? 

Anybody that wants to properly design an irregular shape pod using a woofer tester is in a world of pain. Brace yourself, the planar's impedance is far from being your only problem.


----------



## thehatedguy

That's it, I'm going to measure my car tomorrow and see if those Neo8s will fit.

And I'd skip the supercharger and go straight for the LSx swap in that car.


----------



## subwoofery

thehatedguy said:


> That's it, I'm going to measure my car tomorrow and see if those Neo8s will fit.
> 
> And I'd skip the supercharger and go straight for the LSx swap in that car.


Don't like your whispers anymore?  

Kelvin


----------



## 24th-Alchemist

> Someone show me my totalitarian statement about linear speakers is wrong





> Let me see if I can come up with a counterexample to your theory that may bring brownie points for a CSD graph.
> 
> 1.MLLSA graph number one has perfect decay and a perfectly flat response. Think unobtanium speaker here.
> 
> 2.MLLSA graph number two also has perfect flat response, but also displays a perfect flat delay on the order of 1 ms for all frequencies.
> 
> Take both speakers above and test the frequency response only. The FR will look perfectly flat for both speakers (it will tell you both are perfect). In reality the CSD plot will tell you speaker 1. is in fact better. Speaker two has an equal "ringing" at all frequencies. When summed up in an FR graph this "third dimension" is lost.
> 
> IF planars have less ringing at all frequencies, this intrinsic benefit of planar technology would be ...lost in translation in an FR graph would it not?


Wow. IMO this is a very creative and insightful counter-example proposal. I'm tempted to say mission accomplished (i.e. counterexample provided), but there are a few things that I don't understand that leave me unsettled.

First, it is fact (proven theoretically) that identical impulse responses have identical frequency responses (FR's). (This is not easy to prove but it can be verified from many external sources). So -- non-linearities aside -- in order for the above two FR's to exist, they _must_ be different. But perhaps the differences exist outside the 20-20k band where both FR's are flat.

Consider speaker 1. If by "perfect decay" it is meant that the speaker has no output when there is no input (no stored energy), then it seems to me that perfectly flat FR need not be stated as an additional attribute b/c it is implied. The reason for this is that if no input implies no output, then it must be that an impulse input yields impulse output (b/c otherwise there's an output with no input, i.e. stored energy and hence non-ideal decay). But the only way an impulse input yields an impulse output is if the speaker perfectly reconstructs all inputs; i.e. the the speaker has a flat FR of infinite bandwidth. Thus the (infinitely) fast decay of speaker 1 would be an obvious expectation from its extended FR outside the audio band.

What about speaker 2? What would the FR of speaker 2 look like if it stored equal amounts of energy at all frequencies in the audio band (20-20k Hz). I think its FR would necessarily decay to 0 outside the audio band (e.g. outside 20-20k Hz). I suspect that the the faster the FR decays to zero outside the audio band, the slower the time decay on the time-frequency (3D) plots.

I arrive at the above conclusion b/c the opposite extreme of a perfect speaker (FR mag 1 at all freqs) in this example is a perfect bandpass: i.e. FR mag 1 at 20-20k Hz, 0 phase and freq mag 0 outside 20-20k Hz. I believe the impulse response, call it _y_, of such a speaker takes the form _y(t) = cos(at) * sin(bt) / (bt)_, where the constants _a_ and _b_ depend on the 20 Hz and 20 kHz boundaries. As, say, the 20 kHz boundary is pushed out to higher freqs, the decay of the corresponding impulse response in time is much quicker, and thus I suspect the "3D plots" would show this decay which could be inferred from the FR plot. To generalize for linear systems, I suspect that quicker decay outside FR passband implies slower decay in time, and vica-versa. And perhaps this is why audiophiles like tweeters with FR that extend outside the "audible" band: better transient response and perhaps truer reproduction of sound.

Four more points.

(1) Are the 3D plots normalized? To see why this might be important, consider a sensitive, fast decay driver versus a less sensitive, slow decay driver. In terms of detectable energy above an absolute threshold, the slower decaying, low sensitivity speaker may appear to settle down quicker although it does not have the quickest decay but instead is just less sensitive. Building on this, a speaker with a damped, "sticky" suspension might show a quick decay due to it suspension non-linearities, while a different speaker with a "truer" suspension might show a slower decay b/c it is in fact _more_ linear and more true. Now which would sound better or worse and why?

(2) If we conduct thought experiments such as these, considering various ideal situations, and we don't quite understand what is going on, then how do we expect to draw meaningful interpretations from the plots we examine? To me it seems that in order to glean worthwhile information that helps us improve our audio systems, we need to understand what will happen and why it will happen for various ideal hypothetical situations. Even more difficult, from there we need to understand what will happen when "real-word" difficulties are added to the mix, such as non-linearities. But how do we use these linearly based analytical tools to understand non-linearities in some intelligible way? I'm not saying it's impossible, I'm just saying that I think care and respect are required to obtain worthwhile benefits.

(3) So, I like the insight in the counter example but sitting here trying to consider the "what-if's", it seems to me that broadly speaking time decay can be inferred from the decay of the FR plots outside the driver passband -- at least for linear components. (And as for non-linearities, where do we even begin?)

(4) The time windows used to generate the 3D plots affect the appearance and integrity of the data available from the 3D plots -- its own topic.

I'm open to more insight and please explain if anyone thinks what I've tried to describe is misguided.

_Edit: changed sin(at) to cos(at)_


----------



## cvjoint

I read this last night after a few beers and couldn't makes sense of most of it. Today, after sleeping and sobering up it still is fairly heavy stuff. 

In my example I wouldn't say the FR graphs are the same. They are similar in that both are flat, but the speaker with the imperfect decay would have a shifted FR, up towards more output. Does the FR graph combine output for each frequency over all time periods there is decay? That's how I understand it. 

In number 4 do you mean simply shifting axes?

All your points are right on the money from what I can tell. Unfortunately there are only a few giants that can hang with this theory. I'm afraid the Lycan button hasn't worked much lately. 



24th-Alchemist said:


> Wow. IMO this is a very creative and insightful counter-example proposal. I'm tempted to say mission accomplished (i.e. counterexample provided), but there are a few things that I don't understand that leave me unsettled.
> 
> First, it is fact (proven theoretically) that identical impulse responses have identical frequency responses (FR's). (This is not easy to prove but it can be verified from many external sources). So -- non-linearities aside -- in order for the above two FR's to exist, they _must_ be different. But perhaps the differences exist outside the 20-20k band where both FR's are flat.
> 
> Consider speaker 1. If by "perfect decay" it is meant that the speaker has no output when there is no input (no stored energy), then it seems to me that perfectly flat FR need not be stated as an additional attribute b/c it is implied. The reason for this is that if no input implies no output, then it must be that an impulse input yields impulse output (b/c otherwise there's an output with no input, i.e. stored energy and hence non-ideal decay). But the only way an impulse input yields an impulse output is if the speaker perfectly reconstructs all inputs; i.e. the the speaker has a flat FR of infinite bandwidth. Thus the (infinitely) fast decay of speaker 1 would be an obvious expectation from its extended FR outside the audio band.
> 
> What about speaker 2? What would the FR of speaker 2 look like if it stored equal amounts of energy at all frequencies in the audio band (20-20k Hz). I think its FR would necessarily decay to 0 outside the audio band (e.g. outside 20-20k Hz). I suspect that the the faster the FR decays to zero outside the audio band, the slower the time decay on the time-frequency (3D) plots.
> 
> I arrive at the above conclusion b/c the opposite extreme of a perfect speaker (FR mag 1 at all freqs) in this example is a perfect bandpass: i.e. FR mag 1 at 20-20k Hz, 0 phase and freq mag 0 outside 20-20k Hz. I believe the impulse response, call it _y_, of such a speaker takes the form _y(t) = cos(at) * sin(bt) / (bt)_, where the constants _a_ and _b_ depend on the 20 Hz and 20 kHz boundaries. As, say, the 20 kHz boundary is pushed out to higher freqs, the decay of the corresponding impulse response in time is much quicker, and thus I suspect the "3D plots" would show this decay which could be inferred from the FR plot. To generalize for linear systems, I suspect that quicker decay outside FR passband implies slower decay in time, and vica-versa. And perhaps this is why audiophiles like tweeters with FR that extend outside the "audible" band: better transient response and perhaps truer reproduction of sound.
> 
> Four more points.
> 
> (1) Are the 3D plots normalized? To see why this might be important, consider a sensitive, fast decay driver versus a less sensitive, slow decay driver. In terms of detectable energy above an absolute threshold, the slower decaying, low sensitivity speaker may appear to settle down quicker although it does not have the quickest decay but instead is just less sensitive. Building on this, a speaker with a damped, "sticky" suspension might show a quick decay due to it suspension non-linearities, while a different speaker with a "truer" suspension might show a slower decay b/c it is in fact _more_ linear and more true. Now which would sound better or worse and why?
> 
> (2) If we conduct thought experiments such as these, considering various ideal situations, and we don't quite understand what is going on, then how do we expect to draw meaningful interpretations from the plots we examine? To me it seems that in order to glean worthwhile information that helps us improve our audio systems, we need to understand what will happen and why it will happen for various ideal hypothetical situations. Even more difficult, from there we need to understand what will happen when "real-word" difficulties are added to the mix, such as non-linearities. But how do we use these linearly based analytical tools to understand non-linearities in some intelligible way? I'm not saying it's impossible, I'm just saying that I think care and respect are required to obtain worthwhile benefits.
> 
> (3) So, I like the insight in the counter example but sitting here trying to consider the "what-if's", it seems to me that broadly speaking time decay can be inferred from the decay of the FR plots outside the driver passband -- at least for linear components. (And as for non-linearities, where do we even begin?)
> 
> (4) The time windows used to generate the 3D plots affect the appearance and integrity of the data available from the 3D plots -- its own topic.
> 
> I'm open to more insight and please explain if anyone thinks what I've tried to describe is misguided.
> 
> _Edit: changed sin(at) to cos(at)_


----------



## thehatedguy

I love them, I really do. I do miss the efficiency of other speakers though.



subwoofery said:


> Don't like your whispers anymore?
> 
> Kelvin


----------



## cvjoint

thehatedguy said:


> I love them, I really do. I do miss the efficiency of other speakers though.


How does that song go? 
How many whispers does it take till you get to the bottom of the oc-tave?


----------



## cvjoint

Well, here is the Faitality line array decay plots. I'm going to lay out what I believe we're seeing. If anybody thinks I'm wrong, let me know. I like to know what I'm doing too. 

First, a cumulative spectrum decay. Specs:
Window 15ms
EQ. option selected (flattens out the FR)
Vol 36 on my head
Scale 16m, 5db, reference output at -15










Tone burst
5 cycles
Window 15ms
EQ. option selected (flattens out the FR)
Vol 36 on my head
Scale 16m, 5db, reference output at -15











My guess is that if I test both the planar and the line array at the same output level, I pick the option to flatten EQ, and I keep my scales fixed we should get enough traction on the decay. I will have to meter the line array at 36db on my head, it's probably 7db more than the Neo 8, so I will test that one at vol 43. I know this is all linear distortion and output shouldn't matter but it would be nice to keep the same S/N ratio fixed too. 

What do you all think? Are these giving us anything more than the frequency response graphs? I think they do but I'm weak on the theory. Maybe that's the wrong question. I know the FR and CSD are both based on the impulse response and they are both linear in nature. I'm just thinking the decay is easier to read from a CSD plot whereas it's all bunched up in an FR.


----------



## thehatedguy

I have a hunch that if you took the two graphs, overlaid them, and then subtracted out the common areas, that you might start to get a peak at the non-linear nature of the speaker.

Does that make any sense to anyone?


----------



## 60ndown

that graph reminds me, 



i must get a ski pass.


----------



## cvjoint

thehatedguy said:


> I have a hunch that if you took the two graphs, overlaid them, and then subtracted out the common areas, that you might start to get a peak at the non-linear nature of the speaker.
> 
> Does that make any sense to anyone?


That's exactly what Mark K does for some of his tests. Unfortunately I can't overlap CSD or tone burst graphs. However we can put them side by side and see which one decays faster. As far as knowing what the difference is between the Linkwitz tone bursts and the regular CSD I don't have a guess. I would think they should paint the same picture.


----------



## 24th-Alchemist

Regarding my previous post



> I read this last night after a few beers and couldn't makes sense of most of it.


Yeah, I wasn't expressing myself well. I'll try one more time with pictures instead of words below.

... But first a few reactions (without much explanation) to some of what was posted above.



> They are similar in that both are flat, but the speaker with the imperfect decay would have a shifted FR, up towards more output. Does the FR graph combine output for each frequency over all time periods there is decay? That's how I understand it.


If I understand that quote, I think it is *not* correct. I will address it momentarily -- and hopefully succinctly -- with some plots.

Regarding the posted _line array decay plots_



> Are these giving us anything more than the frequency response graphs?


For perfectly linear speakers, I think not; but ...



> I'm just thinking the decay is easier to read from a CSD plot whereas it's all bunched up in an FR.


... which seems reasonable to me. Also, as has been stated, the CSD plots might help tease out some non-linearities.


QUALIFIER: I'm not trying to pretend I know everything, I'm just trying to establish a position and defend it. If I'm shown I'm wrong, good; I learned something. What I attempt to avoid, however, is just agreeing with ideas -- even if they sound reasonable -- if they leave any gaps or questions open.

For me, in order to have some confidence in drawing meaningful inferences from these plots, I like to understand them in "control" situations, i.e. situations where we know what's going on -- as opposed to starting out with a driver, where we can't be sure if "anomalies" in the graphs are because the driver is imperfect, or our understanding of the graphs is imperfect. And if the driver is the culprit, what does the CSD mean in terms of sound?

Now to the pictures . . .

I invite people to ask themselves: what would one of these CSD plots look like for the impulse response of a hypothetical, perfectly linear midbass driver with an acoustical bandpass response as follows: 12 dB/oct HP at 80 Hz (butterworth); 12 dB/oct LP at 250 Hz (Butterworth)?

Below is a pic of the "CSD" of such an impulse response, which I call the "3-way" midbass (80-250 Hz passband).











To generate my version of a "CSD" I performed the following: I simulated the impulse response of the 3-way Midbass (80-250 Hz passband, 12 dB/oct Butterworth roll-off). (The simulation is important because it generates a _known_ ideal). Then I sectioned off 10 ms windows of the impulse response (0-10 ms, 10-20 ms, etc), and took the Fourier transform of each section to get the FR over each section of time (centered at 5 ms, 15 ms, etc).


Next I will show the "CSD" for the same scenario but with one change: the LP frequency is raised from 250 Hz to 2500 Hz, simulating what I call a perfectly linear "2-way Midbass".

I invite folks to predict how the CSD will change. In particular, how will various frequencies decay differently?

Below is the CSD for the 2-way Midbass (80-2500 Hz passband, 12 dB/oct Butterworth rolloff). It was produced exactly as described above for the 3-way midbass.











Here are my comments, directed at countering the idea that, at a particular frequency on the FR curve, the FR magnitude indicates the degree of stored energy and rate of decay.

Look at the decay along the 1 kHz line, comparing the two responses. Notice that the 2-way midbass -- with its 80-2500 Hz passband -- initially has much more energy along 1 kHz, yet the energy along 1 kHz decays to 0 dB prior to 35 ms. In contrast, the 3-way midbass -- with its 80-250 Hz passband -- initially starts with much less energy in the 1 kHz band (as expected since 1 kHz is outside its passband). Nonetheless, we can see from the first plot that the 1 kHz energy just starts to approach 0 dB at 45 ms. So the energy decay in the 1 kHz band is much _slower_ for the 3-way midbass (80-250 Hzpassband), even though on its FR plot the magnitude at 1 kHz is relatively low.

Look also at the low freq decay (below the 80 Hz HP). Both speakers have the same HP, yet the one with the wider passband decays quicker even at low freqs below the 80 Hz HP that is common to both speakers. (2-way midbass is 0 dB for *all* freqs by 45 ms, whereas 3-way midbass still has energy below 80 Hz).

In my prior post I was trying to predict these phenomena in words and explain why they occur. I think I have verified those contentions in the plots created for this post.

A possible real-world corollary: if you use a speaker that has a flat FR extending into freqs that are much higher than the freqs the speaker is intended to reproduce, the speaker's energy storage will be less of a factor than the "energy storage" that results from the signal bandpass (as long as the speaker is reasonably linear).


Soapbox: For me, I need to be comfortable with "theoretical" known situations before I can have much confidence using analytical tools in the real world, where things are much more difficult. A plausible explanation that sounds good is not enough for me, because I've seen way too many "plausible" explanations that turn out to be ... WRONG -- including most of my own "plausible explanations" 

IMO this is a very interesting thread and it's really got me thinking. Thanks for all the insight so far, and I hope it continues. I'm still trying to learn and I hope I've made my thoughts clear enough for people to react.

-------------------------



> In number 4 do you mean simply shifting axes?


No. See the ripple in the first plot I posted? It's an artifact of the window. And I suspect it's related to the "frequency correction" in the plots you posted. More info about the windowing would be required to comment in more detail.

Regarding these type of plots, here's a cut-n-paste that summarizes some of what several people have posted in this thread. The quote is from the website of someone I consider to be a web guru in sound reproduction, Siegried Linkwitz, answering the question of why he doesn't favor CSD plots:



> My reason for a measurement is to glean relevant information from the data presentation. The waterfall plot (cumulative spectral decay or amplitude-time-frequency presentation) is full of processing artifacts due to the necessary windowing operation performed on the impulse response. This masks information and makes it difficult to interpret what you see. The time axis is usually too short (3 ms) due to lack of anechoic measurement conditions to present anything of relevance below a few kHz. Add to this dilemma the auto-ranging of amplitude relative to the highest peak in the initial frequency response. This has the effect that a tweeter with a 22 kHz resonant peak of 10 dB pushes the whole presentation 10 dB closer to its floor so that the spectrum appears to decay very rapidly. The plots have limited usefulness and must be read with considerable understanding of how they are generated, but they provide attractive advertising and magazine graphics.
> The concept of observing signal decay, though, is very relevant for finding stored energy phenomena. The impulse response contains all this information, but is difficult to interpret in most cases, because of its broad spectral coverage. I prefer to use a shaped tone-burst, 1kblkman4.wav, which concentrates the energy into a narrow frequency band, and observe its decay for different frequencies. The presentation is similar to the energy time curve, except that the ETC is dominated by high frequency (>1 kHz) spectral content, while I can probe any part of the spectrum with constant 1/3 octave resolution. A CD with recorded burst signals for room and speaker tests is available.


(Quoted material from A17 here.)

Real-world Lesson: if we want to improve our understanding of audio reproduction, we should not forget about "the website".


One sentence from the quote that summarizes what I've tried to say in several paragraphs: "_The plots have limited usefulness and must be read with considerable understanding of how they are generated_".

Nonetheless, the next sentence form the quote is "_The concept of observing signal decay, though, is very relevant for finding stored energy phenomena._" So I say press on _cvjoint_, press on! Let's see what you can help us all learn and understand.


Comments: (*) I used lower freq's in my examples -- as stated in the quote above, high freqs are hard to manage with the CSD's. (*) Shaped tone bursts were used in the real speaker responses above, correct? (*) Is the window really 15 ms for the real speakers? That seems really long for the frequencies being examined.


----------



## cvjoint

24th-Alchemist said:


> Regarding my previous post
> 
> 
> 
> Yeah, I wasn't expressing myself well. I'll try one more time with pictures instead of words below.





24th-Alchemist said:


> Nah, it's just a steep climb to where you are. The graphs do help, I am starting to understand a lot of what you posted earlier now.
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> ... But first a few reactions (without much explanation) to some of what was posted above.
> 
> 
> 
> If I understand that quote, I think it is *not* correct. I will address it momentarily -- and hopefully succinctly -- with some plots.
> 
> 
> 
> So is the FR merely the first section of the impulse response, Fourier transformed (0ms)?
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> Regarding the posted _line array decay plots_
> 
> 
> 
> For perfectly linear speakers, I think not; but ...
> 
> 
> 
> ... which seems reasonable to me. Also, as has been stated, the CSD plots might help tease out some non-linearities.
> 
> Click to expand...
> 
> Let me see if I get this right. If both speakers are linear, or non-linear but have exactly the same non-linearities the CSD would not be able to show me which decays faster. Now, all speakers are of course non-linear and differ so by the construction of the CSD I could not observe an "overall" quicker decay.
> 
> When you say teasing out non-linearities you mean time domain aberrations? I tend to get stuck on THD and IMD with that word.
> 
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> QUALIFIER: I'm not trying to pretend I know everything, I'm just trying to establish a position and defend it. If I'm shown I'm wrong, good; I learned something. What I attempt to avoid, however, is just agreeing with ideas -- even if they sound reasonable -- if they leave any gaps or questions open.
> 
> Click to expand...
> 
> Sounds like somebody that spent lots of time cracking open books. I think most people should try to go through a Ph.D. program just to get this view on life. Some folks on this forum always expect qualifiers, as if without them things are any different. We could be wrong about everything of course, we can only find out through...more research! One of these days I'll have to start cranking on my work too or I'll get my ass thrown out of grad school. Car audio doesn't pay for ME.
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> For me, in order to have some confidence in drawing meaningful inferences from these plots, I like to understand them in "control" situations, i.e. situations where we know what's going on -- as opposed to starting out with a driver, where we can't be sure if "anomalies" in the graphs are because the driver is imperfect, or our understanding of the graphs is imperfect. And if the driver is the culprit, what does the CSD mean in terms of sound?
> 
> Now to the pictures . . .
> 
> I invite people to ask themselves: what would one of these CSD plots look like for the impulse response of a hypothetical, perfectly linear midbass driver with an acoustical bandpass response as follows: 12 dB/oct HP at 80 Hz (butterworth); 12 dB/oct LP at 250 Hz (Butterworth)?
> 
> Below is a pic of the "CSD" of such an impulse response, which I call the "3-way" midbass (80-250 Hz passband).
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Click to expand...
> 
> Very interesting. I'm happy you know how to run this as sure as heck wouldn't know. It seems like there is a normalization of sorts with this procedure that yields fake decay. My expectation was that there wouldn't be anything to show for the rest of the sections. What if you don't simulate something band limited, would there be no artifact? The impulse response must be limited though, is it something like 0hz-50khz or truly just a uniform function?
> 
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> To generate my version of a "CSD" I performed the following: I simulated the impulse response of the 3-way Midbass (80-250 Hz passband, 12 dB/oct Butterworth roll-off). (The simulation is important because it generates a _known_ ideal). Then I sectioned off 10 ms windows of the impulse response (0-10 ms, 10-20 ms, etc), and took the Fourier transform of each section to get the FR over each section of time (centered at 5 ms, 15 ms, etc).
> 
> Click to expand...
> 
> This is very useful. There is much to be understood just by knowing how you run it. It also helps me express things in the same language.
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> Next I will show the "CSD" for the same scenario but with one change: the LP frequency is raised from 250 Hz to 2500 Hz, simulating what I call a perfectly linear "2-way Midbass".
> 
> I invite folks to predict how the CSD will change. In particular, how will various frequencies decay differently?
> 
> Below is the CSD for the 2-way Midbass (80-2500 Hz passband, 12 dB/oct Butterworth rolloff). It was produced exactly as described above for the 3-way midbass.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Click to expand...
> 
> So the normalization of sorts is very sensitive to bandpasses. This means fullrange drivers naturally would appear to have a much better decay, when in reality they may not. The million dollar answer for me would be to this question: If I
> *use the same window
> *use the same band pass (and it is within the driver's passband, before -3db points)
> would I be able to compare decay for two speakers? Would I still need to equalize both (I'm guessing Dayton Omnimic does this for me)? When the Omnimic equalizes things out I wonder if it does it for the full bandwidth of the impulse, whatever that is, or just 200hz-20,000hz for my graphs. I suspect if one is able to equalize throughout then the bandpass artifacts wouldn't be a worry.
> 
> Are there other things, outside of bandpasses that may skew the results? I would guess output is not since this is all linear talk.
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> Here are my comments, directed at countering the idea that, at a particular frequency on the FR curve, the FR magnitude indicates the degree of stored energy and rate of decay.
> 
> Look at the decay along the 1 kHz line, comparing the two responses. Notice that the 2-way midbass -- with its 80-2500 Hz passband -- initially has much more energy along 1 kHz, yet the energy along 1 kHz decays to 0 dB prior to 35 ms. In contrast, the 3-way midbass -- with its 80-250 Hz passband -- initially starts with much less energy in the 1 kHz band (as expected since 1 kHz is outside its passband). Nonetheless, we can see from the first plot that the 1 kHz energy just starts to approach 0 dB at 45 ms. So the energy decay in the 1 kHz band is much _slower_ for the 3-way midbass (80-250 Hzpassband), even though on its FR plot the magnitude at 1 kHz is relatively low.
> 
> Look also at the low freq decay (below the 80 Hz HP). Both speakers have the same HP, yet the one with the wider passband decays quicker even at low freqs below the 80 Hz HP that is common to both speakers. (2-way midbass is 0 dB for *all* freqs by 45 ms, whereas 3-way midbass still has energy below 80 Hz).
> 
> In my prior post I was trying to predict these phenomena in words and explain why they occur. I think I have verified those contentions in the plots created for this post.
> 
> A possible real-world corollary: if you use a speaker that has a flat FR extending into freqs that are much higher than the freqs the speaker is intended to reproduce, the speaker's energy storage will be less of a factor than the "energy storage" that results from the signal bandpass (as long as the speaker is reasonably linear).
> 
> Click to expand...
> 
> When you say assuming the speaker remains linear do you mean all these tests should be done at low output or simply a flat FR?
> 
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> Soapbox: For me, I need to be comfortable with "theoretical" known situations before I can have much confidence using analytical tools in the real world, where things are much more difficult. A plausible explanation that sounds good is not enough for me, because I've seen way too many "plausible" explanations that turn out to be ... WRONG -- including most of my own "plausible explanations"
> 
> IMO this is a very interesting thread and it's really got me thinking. Thanks for all the insight so far, and I hope it continues. I'm still trying to learn and I hope I've made my thoughts clear enough for people to react.
> 
> Click to expand...
> 
> Well I can make baffles and such, not much of a contribution on my part. I love theory and I love empirical work. I'm more of an applied guy but a lot of that comes from the latter being easier for me.
> 
> I'm glad Dayton came up with this testing package as I am able for the first time to compare speakers objectively and more importantly it all makes sense. Some of what I hear shows up in the testing and vice versa. That's very comforting as a hobbyist, I imagine it's like seeing for the first time.
> 
> Oh, yeah and people may not react but be sure, they are watching. Big brother is watching haha.
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> -------------------------
> 
> 
> 
> No. See the ripple in the first plot I posted? It's an artifact of the window. And I suspect it's related to the "frequency correction" in the plots you posted. More info about the windowing would be required to comment in more detail.
> 
> Click to expand...
> 
> I see, you mean window as in the 15ms window I used. That's the most Dayton would allow. Can't dream of testing without reflections in a car so I bunch it all together, driver and environment.
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> Regarding these type of plots, here's a cut-n-paste that summarizes some of what several people have posted in this thread. The quote is from the website of someone I consider to be a web guru in sound reproduction, Siegried Linkwitz, answering the question of why he doesn't favor CSD plots:
> 
> 
> 
> (Quoted material from A17 here.)
> 
> Real-world Lesson: if we want to improve our understanding of audio reproduction, we should not forget about "the website".
> 
> 
> One sentence from the quote that summarizes what I've tried to say in several paragraphs: "_The plots have limited usefulness and must be read with considerable understanding of how they are generated_".
> 
> Nonetheless, the next sentence form the quote is "_The concept of observing signal decay, though, is very relevant for finding stored energy phenomena._" So I say press on _24th-Alchemist_, press on! Let's see what you can help us all learn and understand.
> 
> Click to expand...
> 
> Fixed!  I read this one earlier this week, maybe when you posted the first time, figured it would help. I've been a big fan of his for a while. I used the Seas Excel a lot based on his tests and latter the original choice, Scan Speak Classic kevlar midrange. Both were superb drivers. It's funny to me that lately I've gone from Scandinavian to Italian drivers. In effect these top notch Italian pro drivers are what I would expect American drivers to be, not particularly well polished at first look but devastatingly effective. I suppose JBL and small firms like Adire and AE are like that.
> 
> 
> 
> 
> 24th-Alchemist said:
> 
> 
> 
> Comments: (*) I used lower freq's in my examples -- as stated in the quote above, high freqs are hard to manage with the CSD's. (*) Shaped tone bursts were used in the real speaker responses above, correct? (*) Is the window really 15 ms for the real speakers? That seems really long for the frequencies being examined.
> 
> Click to expand...
> 
> That's the longest window I can use. I don't use a short window to reduce the effect of reflections because in a tiny car like mine that's just impossible. I make no claim my comparisons are ideal in every way for everybody's cars. I am however hoping that if I do keep variables fixed the viewers can still draw lots of inference from my tests and use it wherever.
> 
> One of the graphs I show is a CSD, traditional. The other is a tone burst based on Linkwitz's examples. I can vary the cycles, up to 25 but I don't know what that does so I left it at 5.
> 
> I will now post the help file from the Omnimic on my waterfalls. For reference:
> 
> 
> 
> _"The Waterfall feature becomes available when you click the Waterfall button (above the Frequency Response graph, next to the Smoothing control). Waterfalls are calculated from the impulse response. The position where you click within the Impulse Response graph determines the length of the waterfall calculation, starting from 0ms..
> 
> 
> 
> What does a Waterfall mean?
> 
> A waterfall is an attempt to illustrate on a 3-D graph how the energy decays over a range of frequencies. OmniMic includes two different styles of waterfall processes, selectable by toggling the "Waterfall Type" menu button. Waterfall plots are useful identifying moderate to high Q resonances in a drivers's frequency response. The audibility of the features easily identified in waterfall plots is somewhat controversial, with some research indicating that the higher Q resonances seen in waterfall displays are significantly less audible than low-Q resonances not as visible in waterfall displays. In any event, it should be remembered that waterfall data (and also frequency response data) are simply alternate presentations of information contained within impulse responses.
> 
> 
> 
> A "Cumulative Spectral Decay", or "CSD" waterfall shows a series of time slices approximately indicating the contribution to the total response that is made after the time instant shown in the axis going into the screen. When a loudspeaker is driven with an electrical impulse, the pressure it creates should ideally also represent a pressure impulse. But loudspeaker drivers aren't ideal so they also generate resonances -- pressure waves that decay more slowly at various frequencies. The effects of echoes can hide the resonances in a CSD waterfall, but at higher frequencies the echoes can be removed by "Windowing" the calculation to only include the part of the Impulse Response that occurs before the first reflection (from a surface such as a wall or furniture) reaches the OmniMic. Careful choice of positioning within the Impulse Response is critical, because the effects of any reflections included within the selected portion will contaminate all regions of the graph up to that point on the time axis. Below some frequency determined by where the Impulse Response is clicked and how far along on the time (depth) axis a trace exists, meaningful calculation cannot be done. The graph curve is chopped off at those points on the waterfall display.
> 
> 
> 
> The CSD waterfall calculation process introduces some spurious side effects, so the graph should be viewed in general terms. Exact values along the curves of waterfalls are not usually reliable, rather, the positions and sizes of decaying forward-approaching ridges on the graph indicate frequency and relative intensities of resonances.
> 
> 
> 
> 
> 
> "Toneburst Energy Storage" shows the effect that would occur if the loudspeaker were driven by a short toneburst of energy concentrated near each test frequency. The speaker output would ideally end after the toneburst ended, but realworld devices will continue to ring as the energy stored within dies out. This is similar to a test devised by Linkwitz. The Toneburst Energy Storage data in OmniMic is calculated from a measured impulse response, and the number of applied toneburst cycles can be selected using a control at the bottom right. Like the CSD waterfall, the impulse response can be windowed to remove effects of reflections.
> 
> 
> 
> 
> 
> Features of the Waterfall Displays
> 
> 
> 
> For either type waterfall, the top of the screen reference line is set by the largest feature in the selected frequency range. Both types also allow selection of an "EQ flat" function that adjusts gain at each frequency, as if an ideal equalizer were applied.
> The three axes (vertical intensity, horizontal frequency, and time on the "depth" axis) of the graph can be adjusted as desired for display using scaling controls similar to those on the other OmniMIc graphs. The vertical axis is indicated in decibels and the 0dB reference is at the top line.
> As with the rest of the OmniMic graphs, there are buttons provided for both taking Snapshots of graphs or for sending copies of the screen display to a system printer (if installed on your computer).
> Often selection of the Log format display of the Impulse Response graph will allow for easier location of strong reflections.
> To return to the normal Frequency Response page of OmniMic, click on the "Return to FR" menu button."
> 
> 
> 
> _
Click to expand...


----------



## cvjoint

Made another baffle to test the Neo8 again. I didn't realize there wouldn't even be pod left for the baffle to mount on so I had to use some 3m double sticky to get this thing to mount. There are some hard choices for me in the future for putting the Neo8 back haha.

CSD BG Neo8








CSD Fatality Line Array for comparison









Tone Burst BG








Tone Burst Faitality









My first impression is that there are some obvious ridges in the Faital speaker at 4,000hz and 8000hz. Since they are multiples of each others maybe it's a sign of cone break-up.


----------



## SSSnake

> Quote:
> They are similar in that both are flat, but the speaker with the imperfect decay would have a shifted FR, up towards more output. Does the FR graph combine output for each frequency over all time periods there is decay? That's how I understand it.
> 
> If I understand that quote, I think it is *not* correct. I will address it momentarily -- and hopefully succinctly -- with some plots.
> 
> Regarding the posted line array decay plots


I believe that CV's initial quote is correct as long as the measurement window captures all of the ringing necessary to acheive a flat FR. If you change the measurement window for the second (imperfect) driver the FR should change. It is in this respect that the first driver can be measured and found to be much superior to the second (as well as CSD plots). You're graphs with different passbands actually change the required measurement window to capture the summed response and therefore you are creating the situation that I am alluding to...

I will add a disclaimer as well, I believe this to be correct but I am in no respect an expert.


----------



## thehatedguy

Anyone have a rough idea on the Sd of the Neo8?


----------



## cvjoint

thehatedguy said:


> Anyone have a rough idea on the Sd of the Neo8?


How do you want me to measure it? Mine are for sale now btw.


----------



## cvjoint

I took a chance on the SLS 6.5" 

B&C 6ndl44 vs Peerless SLS 6.5" Battle of the midbass coming soon. I sure hope the little Peerless can handle power. I have 320w on tap for each. It will need it to rival the much more efficient B&C. 

Another fine choice would have been the TB 6.5 subwoofer with 13mm of xmax. Sadly it wont' fit in my S2000, even the SLS requires trimming of some of the window stoppers. Filtered 63hz and up it would never use more than 8mm of it's excursion anyway, and by then the coil would overheat trying to get there.


----------



## 24th-Alchemist

> B&C 6ndl44 vs Peerless SLS 6.5" Battle of the midbass coming soon.


Looking forward to the comparison -- and perhaps also a qualitative impression of the SLS's sound. I've been interested in using the SLS's for midbass duty (63-255 Hz), but I've held off buying because some people have said the SLS is more suited for pure "mini-sub" applications. (Not sure if that's really true, glad you "took the chance").

Still want to comment on some previous posts regarding energy decay but I have to get up for work in less than 4 hours . I did some time-domain simulations -- hopefully I'll get around to posting them.


----------



## cvjoint

24th-Alchemist said:


> Looking forward to the comparison -- and perhaps also a qualitative impression of the SLS's sound. I've been interested in using the SLS's for midbass duty (63-255 Hz), but I've held off buying because some people have said the SLS is more suited for pure "mini-sub" applications. (Not sure if that's really true, glad you "took the chance").
> 
> Still want to comment on some previous posts regarding energy decay but I have to get up for work in less than 4 hours . I did some time-domain simulations -- hopefully I'll get around to posting them.


No rush on the plots. Work is more important.  Looking forward to them. I held off on taking CSD plots of people's cars in the http://www.diymobileaudio.com/forum/member-reviews-product-comparisons/105045-southern-california-test-bin.html because I wouldn't be able to write a tutorial for it. If I can't teach it, I don't really know it. To me it's the next step in catching up with the work in the field. I'm getting the feeling time domain discrepancies are very important in speaker testing and I'd really like to get a handle on things. 

The SLS looked really promising at all times. I bought the CSS because it promised even more but sadly failed to deliver. The biggest impediment to performance in a 7" is probably the suspension. The SLS looks beefy. I saw it next to a Revelator and a XBL driver and it downright looked mighty. The only challenger left could the the Tang Band subwoofer, but there is no way I can fit that. I don't think a lot of us can, small sports car or not. 

Here is my theory. A subwoofer is actually the most desirable for a midbass, probably better than what most refer to as "midbass." The majority of the distortion which will define how the midbass sounds is the nonlinear behavior around the HP filter. This is even more important that near the HP filter for a midrange, since that one must cover 1khz-6khz and that is very sensitive. 

So what we really need is something that can move a lot of air to reduce distortion at 63hz. Xmax is the most important (BL, CMS, LE) in that order. Most manufacturers forget the suspension needs to be optimized so you can rule a lot out for that. Surface area is fixed at a 7" for me otherwise it would be first. Sensitivity is probably next most important followed by thermal ratings. The upper end distortion is the last one on the list. When people say don't use a subwoofer up to 250hz I generally don't listen. It's the behavior at 63hz that matters, it will trump upper end response. 

So the SLS probably has the worst upper end extension. That just tells me it's purpose built to kick ass down low. Perfect. Why would I want to cross a dedicated midbass at 1000hz? At 500hz it looks perfect to me so a 250hz LP is great. No real loss there. 

Ideally I'd want all 7" midbass contenders Klippel tested but it's not really an option. The SLS is a straight drop in for my car (minus the window stopper trimming). Easy choice. I got enough tools to compare to B&C. I have a dedicated bass decay option I can test. I need your help there for sure.


----------



## 60ndown

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-832


----------



## omegaslast

cvjoint are you crossing at 63hz? if so may i ask why? I understand a lot of car audio people throw the number around, but that means nothing to me.


----------



## 60ndown

its the 'nut tickle' frequency.


----------



## omegaslast

cajunner said:


> according to Floyd Toole...
> 
> well, here.
> 
> some good stuff to fill the noggin, on resonances and equalization and long window CSD, etc...
> 
> Harman - Scientific Publications


None of this talks about in car woofer response in a door. Nor can i find any mention of this mythical 63hz number


----------



## Hoye0017

I think the reason you see 63 Hz a lot is because it's a common filter point and equalizer center frequency found in digital processors because it's one of the frequencies in standard 1/3 octave spacing. It's also a significant point for most cars as cabin gain and cabin resonance tends to start at around 60 hz.

For crossovers, it's often the next lowest selectable point below 80 hz. Going from 80hz to 63 hz tends to make a significant difference (depending on slope) in bass output of your mid/midbass drivers. I've found it's my go to point if available to help keep the sub's LPF below 80 hz to keep it from muddying bass imaging and drawing the stage back, assuming the sub is in the trunk.

That said, it's challenging to get significant output around 63 Hz out of a typical 6" driver without pushing it's mechanical limits. I think this is why there has been a significant increase in popularity of 3 way setups with dedicated drivers for that 60-200 range and why those drivers tend to be larger than a 6 incher.

Sorry to threadjack, I really appreciate the debate and info this thread has brought out. I look forward to more.


----------



## BigRed

63hz is no magical number for all vehicles. As a matter of fact many tune around it because of cabin gain


----------



## BigRed

In Jon's sprinter I could feel some energy from his door mounted midbass's on certain tracks. I believe its unavoidable to a certain extent no matter what you do and the steps you take


----------



## cvjoint

omegaslast said:


> cvjoint are you crossing at 63hz? if so may i ask why? I understand a lot of car audio people throw the number around, but that means nothing to me.


Ideally I want the midbass crossed at 63hz 24db slopes. Here are the reasons:

1. Subwoofers seem to be omnidirectional when crossed 63hz 12db slope. 50hz 12db slope would work too of course and 63hz 24db. However, 63hz 6db slope or 80hz with any slope seems to pull the stage back. Some people claim this is due to resonance in the trunk. Could be, I doubt it though. It's mostly that we don't use brick filters and the subwoofer output is generally higher than the rest which mean lots of 100hz material even with a 63hz crossover. Reason number 1 is therefore staging is improved - sub cannot be localized. 

2. Both of my cars using over 10+ midbasses and various other cars I tested have a null at 70hz or so. Also see Geo's thread on the SLS 6.5. He claims this to be one of the main reasons he crosses midbasses low. Midbasses covering 70hz don't suffer from the null but subwoofers seem to. I'd really like to test this at a variety of mic spots and figure out exactly why. Reason number 2 is therefore linear distortion is lower - no null. 

3. I use a bass knob. At the minimum position the frequency response is flat. Turnining it clockwise gives me extra subwoofer output for when the top is down, or the song would sound better boosted etc. It's basically my subjectivity knob.  On amplified music, especially electronica, having control over sub frequencies is really nice. My knob is a gain knob. If I crossed my subwoofers higher, at say 80hz or 100hz it wouldn't sound right boosting the sub. Reason number 3 is therefore better control of subwoofer frequencies only. 

Others:

There may be stereo separation down low and you would miss it with mono subwoofers crossed high. 

Some vocals go down to 85hz, with midbasses crossed low there is better voice matching. 

With certain types of subs the upper response exhibits a sharp rolloff. Not in my car, but big coils subs with no Faraday shielding sound like crap up top. 



In practice I run my B&C 7s 100hz 36db slopes. I do it because they don't have the required xmax or low end sensitivity to cross lower. If I do, THD goes up like crazy. It's very easy to tell they are distorting. So now I have to deal with the null, especially since I still cross my sub at 63hz. So I get low THD, great soundstage, but in turn the frequency response is a bit irregular down low. With a lower crossover (with a beefier driver) I hope to get it all. 

In my Accord I had 10"s crossed at 63hz 24db, and the 15"s crossed 63hz 24db. That was the best midbass transition, output, imaging, phase distortion, THD etc that I've ever had. It's not really an option in the S2000. Somewhere I'll have to make some tough choices.


----------



## cvjoint

Hoye0017 said:


> I think the reason you see 63 Hz a lot is because it's a common filter point and equalizer center frequency found in digital processors because it's one of the frequencies in standard 1/3 octave spacing. It's also a significant point for most cars as cabin gain and cabin resonance tends to start at around 60 hz.
> 
> For crossovers, it's often the next lowest selectable point below 80 hz. Going from 80hz to 63 hz tends to make a significant difference (depending on slope) in bass output of your mid/midbass drivers. I've found it's my go to point if available to help keep the sub's LPF below 80 hz to keep it from muddying bass imaging and drawing the stage back, assuming the sub is in the trunk.
> 
> That said, it's challenging to get significant output around 63 Hz out of a typical 6" driver without pushing it's mechanical limits. I think this is why there has been a significant increase in popularity of 3 way setups with dedicated drivers for that 60-200 range and why those drivers tend to be larger than a 6 incher.
> 
> Sorry to threadjack, I really appreciate the debate and info this thread has brought out. I look forward to more.


Great post. I agree wholeheartedly. Indeed the SLS may fail to have the required stroke, THD plots should tell us just how low it can be crossed. I may end up crossing 80hz just to reduce distortion. 



cajunner said:


> it's not so much the frequency itself but the emphasis on having midbass push clean output that low in the spectrum.
> 
> his reasoning is likely due to an observed audible change in response at a higher crossover frequency that detracts in some way from a realistic stage, likely due to the second and third harmonics that come from a higher crossover point.
> 
> you know that 63 hz fundamental is good for some ringing at 126 hz and 189 hz, which become very audible if gross distortion is being produced, but the alternatives are an 80 hz cross with 2nd HD at 160 hz, and 3rd at 240 hz, some people can detect these artifacts and choose to cross low because of them.


The arguments don't seem to be valid. Crossing lower still means you will reproduce 80hz. In fact, you will get more distortion at 80hz when you cross at 63hz. Why? Crossovers get -3db or -6db at the crossover point. There is more 80hz material that has to be reproduce by a woofer crossed at 63hz and of course more material under 80hz. THD can ONLY go up when crossed lower, even away from the crossover. Therefore people would not cross lower to lower distortion but rather the opposite, they would cross higher. That's why my B&Cs are at 100hz. 



BigRed said:


> In Jon's sprinter I could feel some energy from his door mounted midbass's on certain tracks. I believe its unavoidable to a certain extent no matter what you do and the steps you take


True true. Are you going to tell us that door mounted midbasses suck? 

It's a tradeoff between airspace and baffle rigidity. Doors have more airspace, kickpanels have stiffer baffles, on average. With that said, John did a good job, but yeah I could see his window flexing lol.


----------



## BigRed

No, door mounted midbass's don't suck, but require alot of work to get them to sound good 

Jon went to great lengths to get the results he did. 90% of what I listened to I could not localize the midbass, the other 10% was unavoidable considering the location of the driver.

That being said, he never told me the crossover points, but I put my ear to the driver while music was playing and I would guess the bandwidth is quite narrow, maybe 50-125??


----------



## s4k4zulu

thehatedguy said:


> That's it, I'm going to measure my car tomorrow and see if those Neo8s will fit.
> 
> And I'd skip the supercharger and go straight for the LSx swap in that car.


man good luck with that LSX, i love my krx3 until i press that start button, all bets are off then.


----------



## cvjoint

The thing is, you can do LS9 swap in the S2000 and even get it legalized. In the end, you will still have 7" speakers in the doors whereas the Vette fits 10"s!


----------



## s4k4zulu

cvjoint said:


> The thing is, you can do LS9 swap in the S2000 and even get it legalized. In the end, you will still have 7" speakers in the doors whereas the Vette fits 10"s!


It fits 10" nicely but hell of a deadening. I had the morel 10's on there but the outter fiberglass door was flexing too much. Despite with aluminum channels(from raamat) n bunch of deadening...

on a side note LS9 n 2800lbs pure fun


----------



## cvjoint

*First impression based on build quality*

These are the beefiest 6.5" I've laid eyes on. The surround finally looks like it can handle the long stroke required. Unlike the CSS drivers these are much fatter and much more rigid. The spider is even larger in my eyes than the CSS. I've seen raised spiders in my life but not like this, the whole basket is constructed to raise it substantially. 

The basket has a lot more venting then I thought as well. It's bellow and above the spider. 

The tinsel leads are flat and integrated into the spider. These seem to handle some power, again a lot nicer than the CSS. 

The magnet is oversized and there is a bumped back plate for extra stroke. I can't really compare with the B&C or the CSS as those are neo. I'm going to be handling these by the magnet, any other way seems downright scary! The workmanship itself is spotless, glue joints, surround, connection post etc. 

Playing on my desk everything shakes like mad at very little excursion. This little guy is to be feared!

*Testing Results*

As usual I tested both in my doors at the same volume level, 36/62. The SLS has a 4 ohm coil which means it's getting 320w whereas the B&C is 8 ohm and therefore gets 180w. This corresponds to a theoretical 3db or so. The crossovers are 20hz, 20khz so that you all get to see what they can do in your application as well.

*FR
B&C red
SLS black *










It seems like cabin gain does helps them both dig down to about 40hz. The output is almost identical between the two 20hz to 200hz. The SLS is however getting almost double the power so it is 3db less sensitive than the PA driver for midbass duty. Over 200hz the SLS gets its ass kicked severely. The B&C then is at least 3db more sensitive even down low, and works as a 2 way woofer. The SLS gets no points here, but all these drawbacks do come from its sheer clean excursion. The SlS is a pure midbass, it makes no other claims. Usable bands based on -3 db points:

B&C: 40hz-4,000hz
SLS: 40hz-800hz 

Note the PA driver has a rising response on axis, which is why even over the 200hz-800hz interval it has more output in my door. The dip in the midrange seen in my pillar pods is here for the door mounted woofers too. Note the wide dip 300hz-1,2khz in both drivers. 

*Picture time! *



















Look at how much higher the spider is on the SLS, a full inch, maybe more! That makes for a lot more clean throw. Peerless probably designed this basket in-house. All the other 7s using off the shelf parts are going to have a hard time competing with this purpose built basket. You can always throw a big stupid magnet on a basket but in this case it's all beefed up to support it. I feel this is also the reason the XXLS sub has been the reference since the beginning, it had the suspension to match the beefy motor before anybody even acknowledged it mattered. 














































The fitment is gnarly in the S2000. The door panel has been trimmed to the max but I haven't trimmed the window stopper behind it. There is 1mm between the bumped back plate and the stopper! I love it when I use the space to the max! If the TB speaker is any deeper it wouldn't fit. I could shave 2mm off that stopper before it stops working properly, that's not enough. Looks like the SLS and the S2000 are a match made in heaven. 










THD testing next!


----------



## cvjoint

*THD*

A crossover was implemented to test the driver in a realistic application. I used a high pass xover of 63hz and 24db slopes. No low pass was used. 

*B&C HD @ 100db*










*SLS*










*B&C HD @ 105db*










*SLS *










*B&C HD @ 110db*










*SLS*










*HD @ 100db*: Both are excellent up to 200hz .8% or under. Over 200hz the SLS is merely average until 300hz and rather poor all the way after that. The B&C is superb with the exception of 1,500hz and 3,000hz. I suspect the lightweight cone is a little too soft and breaks up a bit up top, still great but other 7"s might do better over 1,500hz. 

*HD @ 105db*: Same performance as at the lower output level above. The motors aren't stressed at all. 
*
HD @ 110db*: The B&C motor starts running out of breath. Distortion under 200hz increases, the highest point is at about 70hz near the crossover where it reaches 3%. Up top it still keeps it's cool, barely braking 1% in a few spots. 
The SLS is not stressed at all. Barely brakes 1% down at 70hz, there isn't even a pattern of running out of linear excursion, this thing is a beast down low! Note that the fundamental is 5db higher than the B&C over the 60hz-200hz region so it's playing >2 times louder as well! Remarkable performance for a 7." I wouldn't actually believe it if I didn't test it myself. Over 200hz the SLS is a mess just as it was at lower output. 

I think this is it, the purpose build 7" that we've all been hoping for in car audio. Beating the B&C down low is a real challenge for any 7" but the SLS does it with no iffs and buts. It's a superior midbass driver period. The motor seems to be bottomless and I would think the distortion we are seeing is mostly coming from my door getting stressed. The driver's side door has 7% distortion at the same output!!! Something gets really loose in there and it's very audible to my ears as well. 
*
Bellow 100hz SLS is the winner
100hz - 200hz tie
200hz up B&C is the winner*

The B&C is ideal as a 2 way driver, it's a perfect compromise for those that want to cross to a tweeter and I suspect it's the king on the market over the region 200hz-1,500hz. It will probably tie with most HiFi drivers that try to achieve the same thing over and under that region. Dedicated midranges will probably do better over 1,500hz and dedicated midbasses do better 100hz and bellow like we've seen. 

*Power compression:*
None witnessed in any of the drivers. I'm surprised at how well the SLS takes its power. I must have been running at least 200watts out of my 320w available since the gains are maxed out and the volume knob went 54/62 for the last test, and that's with sine sweeps. Well, that and it hit 115db (70hz-180hz) in the last round!!

Based on THD the SLS can only be crossed up to 200hz. Anybody trying to cross higher is looking for a world of pain. 300hz is a decent crossover if you have a really steep slope. 

I never believed in 7" bass drivers before but the SLS made a believer out of me. It's as ****ty as they come over 300hz but man that translates into a gorgeous midbass driver. My rearview mirrors should now read "objects are closer than they appear and they are more steady." I can SEE the cone excursion through the little holes in the door! Without the panel the air gets compressed so much in the door it comes out of the clip holes! I haven't had the air in the door compress since I ran 10s. This is more of a match to 8" woofers than to the rest of the mortal 7"s. I really wished I could test the TB as it is the only one out there with enough balls to challenge it imo.


----------



## CraigE

George, thanks for the testing and info on the SLS 6.5.
I've been using the SLS for about a year, and I now have a better understanding of why I like it so much. 
It can't be beat at about $46 ea.


----------



## SSSnake

I found similar results comparing the 8NDL51 and the SLS8. VERY good info!


----------



## cvjoint

Nice, I'm glad we all get the same feel for these. As far as I can tell SLS is a misnomer for this one, it should be XLS 7. The only series Peerless makes that trades off everything up top for bass performance is XLS and XXLS. It's a lot closer in spirit to the mighty XLS 8 I've owned. The SLS 8 and 10 do have the motor goodies but the suspensions are not compromised up top for bass performance. It's also a truncated 7" by just about any definition. 

Maybe they rate theirs by SD since that giant surround takes up loads of cone area. That would make it a 6.5". It could also be an SLS because of the basket design. The XLS series are a bit nicer. 

<$50 it is but make no mistake, the cost measures it takes are ideal. A sculpted basket, neo motor, and fancier copper shorting rings would arguably due very little for a midbass driver but the costs would be significant. For a minor improvement you could end up paying 3x more. More importantly, other than the TB driver I don't see anything that's a potentially better performance option.


----------



## cvjoint

I dug up more interesting info on the SLS 6.5. Check out the voice coil size:
39mm diamater
24mm long
4 layers

No look at the SLS 8
39 mm diameter
25mm long
2 layers

If the same wire is used I would imagine the SLS 6.5 coil could handle just as much power if not more than the 8. No wonder I couldn't get them to stress. The Seas Excel coils complain with much less juice on tap. 
Look at the ratings on the SLS 8:
Long-term Max Power (IEC 18.3) 220 W
Vs the 6.5:
100h RMS noise test (IEC) 150 W
Long-term Max System Power
(IEC) 50W

The ratings are thermal or mechanical whichever comes first from my understanding of the IEC rating. Hours of material with 6db crest factor. It could be the thermal rating is very very high on the 6.5, 220w or even more. When used with a 63hz high pass the mechanical limits increase by a lot but these tests don't show you that. 

By comparison the B&C coil is:
44mm in diameter
12.5 long
layers? 

None of this is complete info but it is indicative of a very beefy coil. No wonder I can't get them to cry!


----------



## thehatedguy

I thought the SLS6 and 8s were marketed as subs.


----------



## subwoofery

thehatedguy said:


> I thought the SLS6 and 8s were marketed as subs.


Having that high of an Le figure, I guess it won't be as fast responding to signal as marketed midbass only drivers... 
I remember reading from a few DIYers that the SLS drivers are not bad for the money but are not that good for midbass applications. 

Kelvin


----------



## fish

I had the SLS 8's in my doors for a while. They had great output down to 50hz, but up top where they were crossed at 200 & 250hz they kind of lost their snap. Since the 6.5" starts to fall off @200hz, I bet the 8" falls off a bit earlier than that. 

This was just my experience. Thankyou George for posting plots & thoughts.


----------



## cvjoint

The LE does what, slow down the response?! I forgot to test the LE on them before throwing them in but they generally test a lot better than the white sheets list, they are underrated. 

I think some people read in too much into the price tag and marketing. The Peerless classifications have been all over the map, sometimes for cost matching and not necessarily application. Do remember that Peerless is a Hi-Fi producer for HT first and everything else in a far second. What works in a home may not work in a car and vice versa. If their classifications run along the lines of HT then they won't work as well for the car. I would have no problem running some 10" woofers up to 1,000hz in HT but in a car the installation constraints make this an impossibility. Not the same thing at all. 

Check out their site btw:

http://www.tymphany.com/peerless/woofers?page=2
The 6.5 SLS is listed in the "woofer" section
The 6.5 SDS is listed in the "subwoofer" section

It doesn't make sense to me. The SLS is more of a subwoofer than the SDS but they are both great woofers as well. The engineers seems to know this as the test bandwidth for the SLS is only up to 1khz on the white sheets whereas it's 20khz for the SDS. Maybe they have a bad website manager or marketing director. Would you build your car based on what the IT guy knows? Madisound, PE and loads of other dealers classify the drivers by themselves too. What if those categories don't match? 

My best guess is that most of the distortion up top is due to the surround resonance. It's the price to pay for a beefy suspension. The SLS 8 seems to have a more tame profile. It may actually play a bit higher with low distortion. The only way to really know is to test it.


----------



## subwoofery

http://www.adireaudio.com/Files/WooferSpeed.pdf 

There are a couple of flaws in the test but the idea is there. 

Kelvin


----------



## cvjoint

subwoofery said:


> http://www.adireaudio.com/Files/WooferSpeed.pdf
> 
> There are a couple of flaws in the test but the idea is there.
> 
> Kelvin


Let me get the key finding in regards to the LE:

"The inductance cut the high frequency extension - mass did not!"

High LE affects high frequency extension. This is an accepted fact as far I can tell. I think the missing bit for most readers is the translation from time to frequency domain. The implications for a high inductance midbass driver is that the frequency response will be limited in the top octaves. That's it. 

So let's go back to the SLS. Is there a test at all in this thread that shows high frequency response? Is it high enough to be considered a midbass driver? Is the driver's LE a potential problem in midbass applications?


----------



## t3sn4f2

Why doesn't inertia affect transient response?


----------



## thehatedguy

It does. Dan's definition is a little special.


----------



## cvjoint

Ok, before this gets derailed to smithereens, Lycan/Warewolf went out of his way many times on this forum and others to get this paper straightened out. To do justice to his work I urge everybody to read this:

http://www.diymobileaudio.com/forum/car-audio-truth-myths-industry-dogma/87371-fast-bass-slow-bass-myth-vs-fact.html

The thread above will tell you everything there is to know about what constitutes transient response and what the impact of LE, or inductance, is on a speakers transient response. 

Once you read that thread look at the evidence presented in this thread on the SLS *as a midbass driver*. 

First the frequency response:










Then here is a plot I just made in WinISD with the SLS yellow, B&C red, TB 6.5 sub purple:










As a pure midbass we can see the frequency response is very usable up to 200hz in any of these drivers. It is true the SLS starts sloping down in both the simulation and the actual test at about 200hz. Whatever the LE is on this driver it is not high enough to induce any linear distortion under 200hz. When used as a midbass driver, up to 200hz the higher inductance has no impact whatsoever on the frequency response and therefore no impact on the transient nature of the speaker. Thanks to Lycan we know high inductance is only the equivalent of a low pass crossover. My low pass crossover here, 200hz is right at the point the inductance "baggage" starts getting tacked on. It only makes my crossover steeper, that's it. 

The TB is marketed as a sub. Look at how inductance is not even present in the simulations. There is no way LE will ever make this a poor midbass driver. It's a myth and a misconception. 

Let's say we did have a 6.5 sub with an enormous high inductance, so much that the FR wouldn't extend flat to 200hz. This is a small problem. We can use EQ to boost the response and get back a flatter FR. Out of all the problems a midbass driver can have this is the least bothersome and honestly completely a non issue with the SLS, TB, B&C and maybe just about any 6.5 driver. Why? The coil is not big enough on a 6.5" to ever be a problem. EQ can fix it, shorting rings exist etc.


----------



## fish

I think cajunner explained what I was gonna try to explain as different order harmonics. Or, just look at this chart, which is a link Erin has down by his sig.

Interactive Frequency Chart - Independent Recording Network


----------



## cvjoint

If the choice is between an SLS with an LE of .2 and an SLS with an LE of 3 I would pick the first for sure. The reality is the LE is high for a reason, it uses a beefy coil. I would take the benefits of low compression over a light rolloff anyday. 

Cajuner you may not endorse the SLS for other memebers, fine, but you have to give an option right? What do you give them, the one that burns it's coil but summs up perfectly? One of the low stroke varieties that have high nonlinear distortion at 70hz? "High-end" designers make these choices everyday. If we had the perfect driver we wouldn't have to. Every speaker makes tradeoffs, it just happens that the SLS makes the right ones for a midbass driver. 

I'm also not a big believer in tonality matching. A good design will have low enough distortion that the crossover from driver to driver would be undetectable. In the early years I prided myself on picking up the metal vs. paper drivers in people's cars. I would guess what the material is and I got the first few perfect. The problem was, as I listened to more and more cars I realized I was getting lots of mismatches. If the metal cone guys properly account for the breakup it's really hard to tell. That's the thing, you can transition from the most "mellow" paper to the "sharpest" metal cone just fine given distortion is very low at the cross point, aka no pattern.


----------



## thehatedguy

What I think he was getting at is, to some it is important to take in to account what is happening after the XO point as that would still be audible to some degree. He is saying if the speaker is clean to a certain point, the crossover point should take that into account. With a speaker that is clean to 300 hertz, the 300 hertz upper limit should be far enough down in amplitude so that you shouldn't hear it so that it is clean in your desired bandwidth.


----------



## 60ndown

if your parked, on a quiet street.


----------



## cvjoint

thehatedguy said:


> What I think he was getting at is, to some it is important to take in to account what is happening after the XO point as that would still be audible to some degree. He is saying if the speaker is clean to a certain point, the crossover point should take that into account. With a speaker that is clean to 300 hertz, the 300 hertz upper limit should be far enough down in amplitude so that you shouldn't hear it so that it is clean in your desired bandwidth.


I agree with this. The reason behind my recommendations for a 200hz LP with a shallow slope or 300hz with a steep slope was all based on nonlinear distortion. He made it quite clear however that he is not referring to these harmonics, but rather amplitude variations. 

With a 24db slope at 200hz, the SLS output at 400hz where the second order harmonics skyrocket is 24db down + 2db from the LE, so in total 26db. I'm not worried, and in fact the THD at 400hz is really good playing together with the Faitality Array.


----------



## 24th-Alchemist

Thank you _cvjoint_ for posting the work you did with the SLS 6.5's.

I would like to finish up with some things relating to cumulative spectral decay (CSD) that were being discussed when I last posted. Then I will ask some questions about the recent results with the SLS 6.5's.

========================

This section is about the previously discussed CSD's. It also ties in with more recent discussions about the relatively high inductance and early roll-off of the SLS 6.5's.

I'm focusing on two main questions here:
Do speakers with wider band-widths (more high freq capability) resonate at high frequencies longer than speakers with less high frequency capability? (Older question related to CSD's.)
What type of speaker is "faster" (better transient response), wide-band or -narrow? (Relating to SLS 6.5 inductance.)

I provide some empirically based insight into the questions by simulating some behaviors of two different linear speaker-system models:
System 1: 80 Hz High pass (12 dB / oct Butterworth) and 250 Hz low-pass (12 dB / oct Butterworth);
System 2: 80 Hz High pass (12 dB / oct Butterworth) and 2500 Hz low-pass (12 dB / oct Butterworth).

Note that the only difference between the two systems is their low-pass cut-off frequencies: 250 Hz for System 1; 2.5 kHz for System 2.

The first plot below compares the impulse responses of the two systems.










The plot is dived into columns: left column for system 1; right column for system 2. The first row shows system frequency responses (FRs). The second row shows system impulse responses, and the third row shows the remaining energy to be dissipated at each time in the impulse responses. ("Energy" is the area under the square of the impulse response plots; at each time point, "remaining energy" is the area under the square of the impulse response from that time point onwards to the right). The lower right plot is red when it is less than the corresponding plot in the lower left -- i.e. _it is red for all times where the wide-band speaker has less remaining energy to dissipate than the narrow-band speaker_.

The observation I emphasize is that the bottom row of plots shows that the wide-band speaker not only dissipates more total energy, it also dissipates energy faster -- and so much faster in fact that after 1 ms it has less remaining energy to dissipate than the narrow-band speaker. The wide-band speaker gets ahead of the narrow-band speaker in terms of remaining energy to dissipate at about the time when the narrow-band has dissipated about 1/2-2/3 of its total energy.

Refined descriptions of the energy dissipations shown above can be obtained with tools such as the CSDs that were discussed several psots ago. For example, the CSD plot below shows the Fourier transform of 11 ms sections of the impulse responses above; in particular, the time sections are 0-11 ms; 11-22 ms and 22-33 ms.










Broadly speaking, the CSD above shows how the energy dissipated over various time sections -- 0-11 ms; 11-22 ms and 22-33 ms -- is distributed across frequencies.

The primary observation I see is that the wide-band speaker appears to dissipate energy quicker at all frequencies. (Start for example with the time evolution of the CSD along the 1 kHz frequency). This could be somewhat counter-intuitive, because although the wide-band has a higher value on its FR curve at 1 kHz and more energy a 1 kHz initially (see first time-window of CSD), it nonetheless dissipates that energy so quickly that it soon has less 1 kHz energy than the narrow-band speaker, even though the narrow-band system initially starts with less energy at 1 kHz. (And note that it is expected that the narrow-band speaker will initially start with less energy at 1 kHz, because one interpretation of an impulse response is that it is equivalent to exciting a system with energy that is uniformly distributed across all frequencies, and since the FR plots show that the narrow-band system is less responsive at 1 kHz (it attenuates that frequency), it should start out with less 1 kHz energy than the wider band system). 

The CSD isn't quite as simple as described above, which I will return to momentarily. But first I show one more comparison of the two systems: their responses to a four-cycle tone burst that lies within the pass-band of both systems. (The frequency of the burst is at the frequency that I call the "logarithmic center frequency" of the narrow-band system, determined by solving for "_y_" in the system of equations _80*x = y = 1/x * 250_.)










In the bottom row of plots the input (e.g. an audio signal which is the same for both systems) is grey; the system outputs (e.g. sound pressures) are blue. The red vertical lines denote the time at which the input tone burst is back to zero. Notice that the wider-band system appears to decay to zero more quickly than the narrow band (hard to see but it's there), which is in tune with the idea that the wider-band system dissipates energy more quickly.

Although not the main focus here, notice also the phase difference of the two responses. The narrow-band system is in good phase alignment with the input (no time delay) because the frequency of the burst is at its passband center. In contrast, the wider band system has a response that is out of phase. So which transient response is better? The one that is "closer" to the input signal, or the one that decays faster? And how do we define "closer" in a way that is audibly meaningful? Audibly "closer" may not correspond to closer on a time plot. Note also that if the two bandpass signals are summed with other signals, they will not sum in the same way because they are neither the same nor phase aligned - even though their frequency magnitudes are essentially equal. But could their differences be heard? Is the slower decay of the narrow band system in this case audible? There are some very good discussions of such issues that start with subwoofer compensation here.

This ties into the thread referenced in a previous post that talks about transient response and whether inductance or high-pass characteristics are the dominating factor.

To examine this with some plots I modified the systems above so that rather than having Butterworth (Q = .707) HP characteristics, they instead have "ringing" with a Q = 3. This would be like putting a midbass in an extremely small kick-panel enclosure and then low-passing at either 250 Hz (System 3) or 2.5 kHz (System 4).

Below are the modified system frequency responses and corresponding impulse responses.










Notice that the wider-band system still dissipates energy faster, but that the high Q puts a dominating "ring" (oscillation) in the responses that is evident in the impulse responses of both systems 3 and 4. Thus in comparing with the impulse responses for systems 1 and 2 in the first plot, we see that all other things being equal, a "faster" speaker with less inductance does decay more quickly and resonate less, but we also see that a high Q results in resonance that cannot be overcome by a low inductance.

End result: simulation evidence that agrees with the contentions in the referenced thread that "speed" and transient decay are much more effected by Q (i.e. HP characteristics) than by inductance (low-pass characteristics).

Relatedly, if a speaker does have too much inductance, it seems reasonable to me that its inductance could be "EQ'd away" in a fashion analogous to a Linkwitz compensator used at the "high-end" rather than the low-end.

As a last topic, I show some CSD plots of the impulse responses of the aforementioned high Q systems at various CSD "window lengths". Note that by "window length" I do not mean the total duration of the CSD, but rather the length of each section of the overall time-signal that the CSD analyzes in segments.

In the CSD plots we should expect to see the "ringing" from the high Q that is evident in the impulse responses of both systems (the oscillations in the tails of the impulse responses).

If however we use a 2.5 ms CSD window as in the plots below, we do not see the oscillations. (And note that the CSDs posted previously by _cvjoint_ used windows that could be as short as 1 ms). 










If we move to longer windows for the time sections -- 11 ms next -- we still do not see the oscillations very well (see plot below; would you recognize the resonant peaks if you didn't know they were there; also Q = 3 is very high, what if Q was 1.5 instead):











Finally, if we use 25 ms windows as in the CSD below, we see the ringing (oscillations due to high Q) as the bumps around the ~100 Hz ringing frequency. 










Note that 15 ms is apprximately the total time course of the CSDs posted previously by _cvjoint_, and 15 ms would not be long enough to capture the effects shown above, since to see the effects windows of about 2x the oscillation period (25 ms in this example) are necessary to easily see the oscillations in the CSD.

This type of pitfall is expected because one fact of the Fourier transform used to generate CSDs is that as the time window is narrowed (more time resolution), increasingly larger swaths of frequencies are "averaged" to generate the frequency points in the CSD. In this case, the resonant frequency is "averaged away" in the CSD (low frequency resolution), except in the case of very large time windows (the 25 ms plots where the time window is large enough to get better frequency resolution). It begs the question of why use the CSD since we could see the oscillation anyway in the impulse response. Also, there are more distortion problems with CSDs than are described here. See "windowing" as it relates to Fourier transform.

This is taking too long I will post later with questions and comments relating to the SLS 6.5 data.


----------



## 24th-Alchemist

OK I will summarize a few points from my prior post and then ask some Q's about the data from the SLS 6.5's.


========================

First, nothing has been proven in the post above. Instead, trends were established that would serve as motivation to look further into proving that the trends hold in general. Maybe someone else has already established the generalizations and we just need to search for them. Otherwise we might try to prove the trends in general.

Here are the main trends that I see from the simulations:

(1) All other things being equal, a speaker-system with more high-frequency capability (e.g. low inductance) dissipates energy faster, i.e. has a better transient response, than a speaker-system with less high-frequency capability. See for example the plots for systems 1 and 2 in the post above.

Notice that I used the term "speaker-system" because it should go without saying that the combined attributes of both crossovers and electro-mechanical speaker properties are what maters. Take for example a crossover in a three-way system between a midbass and midrange. A person could implement an active electronic crossover that has an impeccable transition between midbass and midrange, but if the electro-mechanical properties of the speakers are not considered in designing the crossover, I think the audible results will be both marginal and mysterious. This is because at a minimum, phase contributions from the HP characteristics of the midbass will degrade the interaction between midbass and midrange if those phase contributions are left unaccounted for.

(However, it's not clear to me how currently available signal processors can be used to account for such issues, so I ended up making my own signal processor, and I tried to describe how others could make their own too in a thread on this forum here.)

(2) Next, if a speaker has a high Q (e.g. from a small enclosure), the high Q will dominate the transient response in a negative way in the form of slowly decaying oscillations, and such oscillations will not be overcome by low inductance. (See for example plots for systems 3 and 4 above). More generally, a speaker's HP Q will affect its transient response more than its low-pass (inductance) characteristic. This same point was made in a thread referenced in the posts above. Also, if a speaker has significant inductance, it in theory that inductance could be compensated for in a way similar to that of a Linkwitz compensator, although I'm not sure how such could be done with currently available processors.

(3) Regarding cumulative spectral decays (CSDs), I tried to illustrate that there are a lot of things happening "behind the scenes" that necessitate careful consideration in order to use the CSDs to draw meaningful inferences. In particular I provided simulation examples showing that a resonant peak at ~100 Hz in a midbass response was not evident in the CSDs until the CSD time windows were around 25 ms each. And this 25 ms is not the total CSD duration (which was around 200 ms), it was just the duration of each individual time-window. In contrast with this, CSDs posted previously had total durations of about 15 ms in order to avoid echos I believe, but such a short duration would not be easy to use to characterize low-frequency attributes due to poor frequency resolution, which is an unavoidable aspect of the windowed Fourier transforms that are used to generate CSDs. The most elementary manifestation of such that I can think of is the Heisenberg uncertainty principle from physics, which broadly speaking says that the position and future momentum of a particle cannot both be known to arbitrarily small degrees of uncertainty. Along a similar vein, as we examine frequency distribution of energy in shorter and shorter time-segments of a time-varying signal, we necessarily increase the distortion in the way that a CSD displays those energy distributions across frequencies, where the distortion is in the form of averaging across a wide band of frequencies to estimate the energy density at a particular frequency (see CSDs with varying window lengths for systems 3 and 4 in the post above). It turns out that distortion in CSDs is significant at time scales that are considered "long" for car audio, and shortening the time-windows only makes CSD distortion worse. It doesn't mean that CSDs can't be useful though, it just means that their parameters should be set with understanding and that interpretations should be made with care.


====================================

Now to some questions about the SLS 6.5 data.

_cvjoint_ thank you again for both collecting the data and for posting about it. Thank you also for all your insight, which to me seems well thought out and reasonable.

I do however have two main questions that I hope people will respond to.

The first is what seems to be the consensus that inductance is what causes the SLS to have the FR dip beginning around the 200 Hz range. I see several possible problems with this.


First, the SLS data sheet indicates that the woofer has a voicecoil inductance (Le) of 0.65 mH and a voicecoil resistance (Re) of 2.7 Ohms. If I understand things correctly, the low-pass cut-off frequency _fc_ of the associated lowpass filter is given by _fc = Re / (2 pi Le) = 2.7 / (2 * pi * 0.65 mH) = 661 Hz_, which corresponds more closely to the roll-off frequency shown on the data sheet, so aren't we off a little in attributing a 200-300 Hz roll-off to speaker inductance? 
Second, the roll-off should be 6 dB / oct at the steepest, yet to my eye the observed roll-off looks to be as steep as 24 dB / oct. (The roll-off is also very steep around 700-800 Hz in the data sheet, which I don't understand either).
Third, the other speaker seems to follow a similar, albeit less substantial, trend around 200-300 Hz, so I'm wondering whether the roll-off might be an artifact of the particular testing environment as opposed to an attribute of the driver.
The other main question is that I'm confused, on paper at least, about how the SLS gives a significant linear-range output upgrade relative to other 6.5's. This is because what the SLS appears to gain in stated linear stroke (Xmax), it almost equally gives up in cone area (Sd), relative to other 6.5's. Let's take some Peerless 7-inch models for comparison:
a SLS,
a SDS, and
a HDS.

Their respective Xmax and Sd specifications are
3.46 mm, 141 cm^2;
8.2 mm, 123 cm^2; and
5.34 mm, 143 cm^2.

If we take the product of Xmax and Sd as the effective linear volume displacement we get
SDS = 48.8 cm^3;
SLS = 100.9 cm^3; and
HDS = 76.4 cm^3.

So yeah the "subwofer" SDS gets left behind but in light of the fact that we are dealing with octaves in the case of audio (i.e. 2x excursion for 1/2 of frequency), is a 33% increase in linear volume displacement really that big of a difference in going from something like an HDS to SLS?

I think there are a lot of midbass drivers with a 5 mm Xmax and an Sd comparable to the HDS's 143 cm^2, so I'm confused about what the SLS really adds. I get that cabin gain can offset low freq roll-off but as the HP cut-off on a midbass is lowered, I think a midbass is forced to accommodate a lot more energy at increasingly lower frequencies. Getting back to CSDs, if we looked at the CSD for windows of an audio track I bet we'd see a lot of energy at low frequencies at times when instruments such as kick drums were active, and I'd bet we'd also see that as frequency lowered the energy involved would increase dramatically.

It seems to me that if a person had a driver with specs something like those of the example HDS crossed comfortably at 100 Hz (fairly attainable for a 7-inch midbass), there would need to be at least a doubling of the Xmax * Sd product in order to comfortably move the HP crossover down to, say, 63 Hz -- and such a doubling is not achieved by the SLS.

One 7-inch midbass drivers that, on paper at least, seems to fit the bill is the
ScanSpeak 18wu-4740T00 with 9 mm Xmax and 154 cm^2 Sd (too spendy though). Also maybe the Exodus Anarchy (but it's not as linear as stated?), or maybe even the new T3 from RF?

I realize _cvjoint_ may have particular restraints that limit driver choices but the marginal 30% increase in Xmax * Sd product afforded by the SLS just isn't computing in my brain. I hope someone can enlighten me.


----------



## cvjoint

I should be tracking my lost luggage in Denmark but this is too exciting to pass. 

With regards to the CSD theory. This is a very detailed simulation of the thread I posted. It seems that one barely scratched the surface compared to your analysis. Amazing work. 

Let me first add that 15ms was the longest window I could test at. The measuring gear thinks the results are good 200hz and up which might not be enough given I cross right there. There is a "Bass decay" option that I should have used in addition to the CSD plots but too late now. If only I had this knowledge earlier! On the other hand I now have more passion for time domain tests, I think it's the missing link in most performance evaluations. 

As far as the application of the results I'm not sure what goes where. _Is the analysis good for impulse responses, for crossover designs, or for actual speaker bandwidth_? 

Say we use the _same speaker_ and bandpass it like in the two examples above. It's not really the driver that decays faster, is it then the crossover or the impulse response artifact? Can we take these results to be descriptive of actual speaker bandwidth? Are they accurate for crossover design, or is it simply an impulse response artifact? What if we measured decay with another technique, would we get the same results?

Disentangling the three could help us answer lots of questions. For now it's safe to say that when using CSDs to compare speakers we should use the same time window and crossover. Beyond that I'm still a little confused. 



_On to the SLS._
In regards to the rolloff, the in car test is inconclusive in the sense that the B&C has a rising response. The car interior reflections make it hard to look at the SLS by itself, and the relative comparison is also flawed given the B&C is not exactly perfectly behaved either. There is however a rolloff in the WinISD simulation that is hard to deny. That was the bulk of the evidence for an early rolloff but it's quite possible it doesn't rolloff until 800hz like the white sheet shows. 

As far as harmonic distortion performance goes, I'm going to stipulate that the xmax on the SLS is significantly truer than in other speakers. What I mean by that is you have to have an _accurate measure of Xmax_ to do the SD+stroke calculation. Working off of the manufacturer sheets is very iffy. Take for example Erin's Klippel test of the 8" HDS:

http://www.diymobileaudio.com/forum/klippel-reviews-driver-specs/108356-peerless-hds-8-nomex-830869-a.html

The white sheet claims an xmax of 4.5mm. In reality there is loads of motor force, linear enough for over 5mm but the suspension reaches the 10% distortion threshold at only 2.2mm. Using the paper xmax you can overrate the output by a factor of >2. 

My guess is that the SLS is good for 6.5mm of clean excursion factoring in suspension, motor and inductance. Even with the much smaller surface area, it may be performing at the level of this 8" if my guess is accurate. 3 times the throw! 

That's the thing, there are lots of manufacturers claiming an xmax of over 5mm for a 7" speaker, but what does that mean? Even if the motor is good for that much if you have a flat surround it's not going to cut it for the surface area-stroke comparison. 

For the record I'm not even that big of a fan of a true xmax either, I think you really need the Klippel curves to make a good inference. Consider drivers A, and B below:

A
X BL:20mm
X C:5mm
X L:>20mm

B
X BL:5mm
X C:5mm
X L:5mm

Both have a true xmax of 5mm but driver _A is bound to have much lower distortion everywhere_. We don't even have true xmax ratings, let alone distortion information separated by motor, suspension and inductance like above. Heck even the specs above would be better with an actual plot of all three over X. Take the next two drivers:

A
X BL:5mm
X C:5mm
X L:5mm

B
X BL:5mm
X C:5mm
X L:5mm

But imagine driver A has a BL curve fit that is a sine (maybe a trick motor done bad) whereas B has a textbook underhung plateau. _B will sound better by a lot._ 

My guess is the SLS shines because it has a good amount of suspension throw, enough to embarrass most 7s by a factor of 2. Peerless is also good at optimization, getting curves to center well to make the most our of their parts. Its single aluminum shorting ring could perform better then the competitors triple copper pieces.

For that matter look at the Scan Speak 12m Klippel report. People were extremely disappointed with Scan's decision to not use shorting rings in this model Revelator. The inductance curve however shows significant effort to curb variance. It's not the shorting ring itself that's important it's linearizing inductance that matters, the final product. It turns out is sounds good after all, a no brainer if you see the Klippel 3mm of true xmax, more than the 8" Peerless.


----------



## cvjoint

cajunner said:


> wow, we're really getting down deep into the muck now!
> 
> I find the new information by 24th-Alchemist very compelling, and considering that there is more to figure out with windowing and Fourier Transform issues, it's certainly given me pause to understand what I'm seeing as relevant in cvjoint's original premise.
> 
> Almost as if cvjoint created the parameters that would necessitate or effect the logical conclusion that fits, and I'm not saying that is what happened but it stands to reason that I have neither the knowledge or skill set to interpret his data correctly, or any data correctly, school's out on that one.. or it's more complicated than just making some measurements and following the definitions in the index. Very good on cvjoint for showing what he could, I can't say if I agree totally with the ideas presented but there could possibly be a tie-in as to why speaker designers choose to have an octave of out-of-band smooth response in their conceptuals on crossovers, as this relates to THD as much I would imagine, as it does to the actual plotting of fundamentals.
> 
> 
> but in following this line of thinking I really am surprised that the conclusive evidence is that wide-band modeling measures better in delay artifacts than breaking up the 20-20K into separate parts.
> 
> I don't yet understand how this changes my auditory perception of either, but the idea that the testing procedures being in conflict with my understanding of how speakers make sound, is disheartening.
> 
> *I think what the two points coming together represent, is that a long-stroking, wide surround sub doing mid bass duty, is actually counter to the principles of energy storage and dissipation profiling that determines the actual intelligible nature or clarity of the response.*
> 
> I myself see evidence of this in the main, as most people design their 3-ways to still use a subwoofer somewhere else in the vehicle and not as a part of a divided pair of stereo sources.
> 
> *Or, it's not possible to have a driver that encompasses the dual natures of sub bass accuracy/spl output with the neutrality/low energy storage of an otherwise unencumbered by high Le, motor design.*
> 
> XBL promised us this, but the nature of an XBL design is limited by motor force due to the air in the gap, so no beans. What about Neo Radial, then? I would suspect that the amount of motor force available depends entirely on what the saturation rate of the steel allows and that particular design, uses a lot of iron in the making, so trying to get "more" BL out of that design is only possible going deep with the motor, not a great feature on door mounting mids..
> 
> Thanks for the extra effort guys.


To me it seems the simulation results say a completely different thing. How about this drawback of the wide bandwidth driver:
"The narrow-band system is in good phase alignment with the input (no time delay) because the frequency of the burst is at its passband center. In contrast, the wider band system has a response that is out of phase."

How about the relative comparison here:
"End result: simulation evidence that agrees with the contentions in the referenced thread that "speed" and transient decay are much more effected by Q (i.e. HP characteristics) than by inductance (low-pass characteristics).

Relatedly, if a speaker does have too much inductance, it seems reasonable to me that its inductance could be "EQ'd away" in a fashion analogous to a Linkwitz compensator used at the "high-end" rather than the low-end."

It frustrates me that we are looking at the same post yet we draw completely different conclusions. The SLS's inductance is really not a big deal at all. 

You know, 90% of the car audio woofers that cross with a tweeter use a generic overhung topology without a shorting ring. All of them are bound to have an equal or higher inductance. Why do you choose to emphasize it so much with the SLS crossed this low? Most 8" woofers will also have a higher LE yet they are almost always better midbass drivers than the lower LE 7" counterparts. Reducing this thread to "SLS sucks because it's a subwoofer" undermines all the hardwork people put in this thread. I'd rather have a million unanswered questions at the end of the thread than a simple yet unsupported conclusion.


----------



## ErinH

George, if you want to send me the sls 6.5" I'd be more than happy to test it. 


Alchemist, thanks for all your input in this thread.


----------



## thehatedguy

I should have some BG Neo8-Ss coming soon...I missed the first batch because I had to replace the heater core in my car, but getting in on the 2nd run.

Sucks that PE isn't getting them though.


----------



## cvjoint

bikinpunk said:


> George, if you want to send me the sls 6.5" I'd be more than happy to test it.
> 
> 
> Alchemist, thanks for all your input in this thread.


That sounds great. I'm in Europe until mid September. They also managed to lose by luggage probably for good. Depending on the financial situation I will update you then. 

On the other hand, it's just a cost issue. I don't mind taking them out and shipping them to you if there are forum contributions.


----------



## ErinH

cvjoint said:


> That sounds great. I'm in Europe until mid September. They also managed to lose by luggage probably for good. Depending on the financial situation I will update you then.
> 
> On the other hand, it's just a cost issue. I don't mind taking them out and shipping them to you if there are forum contributions.


Understood. Now you know why I made such a stink in the past threads about how I wasn't paying for shipping. It gets costly when you pay both ways. Especially if you add insurance. 

What are you in Europe for and where are you?


----------



## cvjoint

bikinpunk said:


> Understood. Now you know why I made such a stink in the past threads about how I wasn't paying for shipping. It gets costly when you pay both ways. Especially if you add insurance.
> 
> What are you in Europe for and where are you?


I know it's $. I didn't even get the refund for the CSS drivers yet, there's going to be a fee too. 

In Denmark now, next Germany on the Nurburgring, Greece island partying, London for a wedding, NY for a wedding. I need every outfit imaginable brand new and man Europe has some expensive malls.


----------



## cvjoint

I've been looking at Zaph's CSD plots casually over the last few weeks. They are found here: Zaph|Audio

It is one of the few sites if not the only that has CSD for all major DIY drivers. You can find the Neo 3 PDR in the battle of nondomes, dome midranges and cones in the small driver comparison. These will be most useful for a pure midrange application 200hz-up for car use. 

Here is some of the trends I see going on. The best decay by technology:
BG planars, ribbons,domes > cones. It is noteworthy that cones seem to decay noticeably slower than the first three. Within the planars ribbons and domes the decay seems to be more similar than different. Cones also seem to have more spot problems with extended ridges. 

The second apparent trend is that small speakers decay quicker than larger speakers. this is apparent in plots between the smaller cones and 7" and 8" groups. There is also noticeable difference between the large TB domes and small domes such as the Hiquphon. 

The real question is can we look at these CSDs and make these inferences? Zaph is good at keeping the DB scale, decay window, and even measuring window fixed. His room also has extensive treatment to absorb unwanted noise. 

The second theory that small cones have better decay than large ones shows up in Linkwitz's tone burst measurements for the Orion as well: 
Midrange distortion test

Based on all of this it seems to me that a rather large line array of plannars or domes is ideal to keep the decay performance good yet have decent output and nonlinear distortion. The polar response should be good too, especially if the line array is taller than the listener. Ok, so that's not going to fit in a car.

In a car I'm thinking the BG Neo8-s or Neo10 coupled with the Neo3 PDR up top might be very nice. The Faital line array would still have better output and nonlinear distortion but the decay gains should be worth it. I'm starting to think time domain aberrations are the reason cone speakers sound like speakers whereas planars, ribbons and domes never really do to me. That is where the transparency comes from.


----------



## fish

Are you back from your 'round the world vacation? 

I haven't completely tossed out the idea of using the Neo8-S in the pillars, but just using a cardboard mock-up sure does show some funky & difficult mounting angles to try & get these somewhat on-axis. But, from what you said about the Neo8's vertical dispersion not really being as bad as people let on, the Neo8-S should be fine up to 6-8k facing a bit downward from my head, into my torso, correct? I need to check your graphs on MSS.

I also need to give my cardboard Neo8 some more looks in the pillars.


----------



## cvjoint

fish said:


> Are you back from your 'round the world vacation?
> 
> I haven't completely tossed out the idea of using the Neo8-S in the pillars, but just using a cardboard mock-up sure does show some funky & difficult mounting angles to try & get these somewhat on-axis. But, from what you said about the Neo8's vertical dispersion not really being as bad as people let on, the Neo8-S should be fine up to 6-8k facing a bit downward from my head, into my torso, correct? I need to check your graphs on MSS.
> 
> I also need to give my cardboard Neo8 some more looks in the pillars.


In London now. I'm out of the Greek party islands so it's time to do some work, especially since I have a good source of internet here. 

The off axis response of the Neo8 really impressed me. There was virtually no mic location where my head could be in the car and not get 12khz flat. As long as you are not using it as a tweeter you'll be fine with almost any firing direction. This may also be a result of installing it in a car. The power response kinda sums up as it bounces of things. 

In the earlier tests the Neo 8 had really low nonlinear distortion up to 10khz. Sometimes these planars have trouble areas that are sort of random. If you look at the Neo10 THD on Zaph's site there is a clear resonance at 5khz. It's not really clear why to me but I venture to say it's the row of magnets and the grille blocking the output on both sides of the planar. Here's a magazine test of the Neo8 that kinda finds the same thing as I did earlier. No real problems above 800hz, unusually low distortion up to 10khz: http://www.diyaudio.com/forums/multi-way/6228-bohlender-graebener-neo-8-magnetostat.html#post63279. 

Decay wise you may want to cross lower depending what you cross with. A 1 inch dome has about the same decay qualities from what I could tell. If you use a Neo3 up top or a 3/4 dome they will probably have a bit better decay qualities. Not sure it's worth getting the slightly better decay performance and giving up the very low distortion performance in harmonics. 

To sum up you can cross as high as you want, up to 12khz I think it's kosher from just about any performance point of view.


----------



## thehatedguy

Too bad you aren't back in the states, my trio of Neo 8Ss have been here for a week or two. Going to use some small AMT-type tweeters with them.


----------



## cvjoint

thehatedguy said:


> Too bad you aren't back in the states, my trio of Neo 8Ss have been here for a week or two. Going to use some small AMT-type tweeters with them.


Meh, it's not like nowehere, overthere is next door, I can't audition! What's this AMT tweeter you are going to use? You got something better than the Neo 3 PDR lined up?


----------



## fish

thehatedguy said:


> Too bad you aren't back in the states, my trio of Neo 8Ss have been here for a week or two. Going to use some small AMT-type tweeters with them.


How/where do you have the Neo8-S mounted? You got any pics?


----------



## thehatedguy

The little AMT-types are marketed by Airborne and are made by Hygeia. I believe they also sell to Elco, Martin Logan, and Adam. The model number is RT-20021. You can take the face plates off and they get TINY. Meniscus has them, but that model isn't on their site. I went with them because they are TINY without the face plate, I never used an AMT-type tweeter, and they had symmetrical radiating surfaces...and I wanted to try something different than the Neo3 that I have had mixed feelings over. Jeff Bagby tested the big brother ones and they tested really well from what he says. A small dome like the Vifas would have been cheaper and covered a larger frequency range.

ºñ¼Íµç×ÓÓÐÏÞ¹«Ë¾

It becomes the 20021 with the face plate. That document is on the Solen webpage.

No pictures of the tweeters of the mids mounted...cause I haven't gotten that far yet. .


----------



## cvjoint

thehatedguy said:


> The little AMT-types are marketed by Airborne and are made by Hygeia. I believe they also sell to Elco, Martin Logan, and Adam. The model number is RT-20021. You can take the face plates off and they get TINY. Meniscus has them, but that model isn't on their site. I went with them because they are TINY without the face plate, I never used an AMT-type tweeter, and they had symmetrical radiating surfaces...and I wanted to try something different than the Neo3 that I have had mixed feelings over. Jeff Bagby tested the big brother ones and they tested really well from what he says. A small dome like the Vifas would have been cheaper and covered a larger frequency range.
> 
> ºñ¼Íµç×ÓÓÐÏÞ¹«Ë¾
> 
> It becomes the 20021 with the face plate. That document is on the Solen webpage.
> 
> No pictures of the tweeters of the mids mounted...cause I haven't gotten that far yet. .


Sexy. Those look great, either they are really small or those phillips screws are enormous. 

How much SPL do you think these can belt out?


----------



## thehatedguy

They are really small.

I'm not sure about the output...I was planning on crossing around 5-6k so I'm sure it would have plenty up there. The AMT is neat because it squeezes the air from between the pleats. It is supposed to give you more attack...I dunno about that though. And if you unfolded the pleats, this little thing is like 8 inches long, so lot of surface area to move the air.

If they suck, I will probably go to the Neo3 PDRs and keep the mids and highs all in the same family.


----------



## thehatedguy

Quick listen to the center with the EQ set for the Whispers and the wrong crossover points for the top of the Neo8 and tweeters. Very promising. Something in the female vocals that is erking me...but I won't worry about it until I get everything done and re-EQed.

There is a LARGE efficiency difference between with dual Whispers and the Neo8 though. Which I think that I have practically quadrupled (2x from the front area increase and and another 2x because it is running dipole on a large baffle) the output and have a higher efficiency to start with.

Has the makings of reminding me of why I fell in love with horns and HE setups.


----------



## cvjoint

thehatedguy said:


> Quick listen to the center with the EQ set for the Whispers and the wrong crossover points for the top of the Neo8 and tweeters. Very promising. Something in the female vocals that is erking me...but I won't worry about it until I get everything done and re-EQed.
> 
> There is a LARGE efficiency difference between with dual Whispers and the Neo8 though. Which I think that I have practically quadrupled (2x from the front area increase and and another 2x because it is running dipole on a large baffle) the output and have a higher efficiency to start with.
> 
> Has the makings of reminding me of why I fell in love with horns and HE setups.


Sweet, you are moving fast. Playing with these planars is always so exhilarating. You don't have to listen critically from changes between a top of the line paper cone and another top of the line plain jane paper cone. The change is real!

If they are anything like the regular Neo8 1600hz-5000hz is usually boosted a bit compared to the rest of the band. Maybe that's what's bringing the female vocals forward. I generally thing the BG planars are super easy to play with. Nothing really irritates me about them, they are very smooth compared to cone technology with spot problems here and there.


----------



## thehatedguy

Yeah my gut feeling was 2k range...which seems to be where you are at too. 

The planars seem to be super easy to design crossovers for in PCD and LspCAD. Both the tweeters and planars have ruler flat impedance curves (if you can call a straight line a curve), and great roll offs on the ends. That 10k bump on the Neo-8Ss goes totally away off axis.

Differently a different sound than the cones and domes. 

I am really excited about the drivers. I spent about 12 hours using Edge and some baffle diffraction software to sim baffles to see where I would be getting dipole bump and dips. And using an 8x10" baffle butted to one edge of the dash, I created a very large baffle without too bad of bumps and dips. The baffle is also slot loading the center midbass. So the back side of the planar and the midbass are exiting the same hole. For some reason that center midbass is digging much deeper and harder than before.

I figured it would the the easiest and fastest way to get it in the car...and if it sucked I would make an enclosure for the planar. So far so good though.


----------



## cvjoint

thehatedguy said:


> Yeah my gut feeling was 2k range...which seems to be where you are at too.
> 
> The planars seem to be super easy to design crossovers for in PCD and LspCAD. Both the tweeters and planars have ruler flat impedance curves (if you can call a straight line a curve), and great roll offs on the ends. That 10k bump on the Neo-8Ss goes totally away off axis.
> 
> Differently a different sound than the cones and domes.
> 
> I am really excited about the drivers. I spent about 12 hours using Edge and some baffle diffraction software to sim baffles to see where I would be getting dipole bump and dips. And using an 8x10" baffle butted to one edge of the dash, I created a very large baffle without too bad of bumps and dips. The baffle is also slot loading the center midbass. So the back side of the planar and the midbass are exiting the same hole. For some reason that center midbass is digging much deeper and harder than before.
> 
> I figured it would the the easiest and fastest way to get it in the car...and if it sucked I would make an enclosure for the planar. So far so good though.


Well you could be getting lots of FR variations in dipole. I'm kinda bummed I didn't play around with my Neos in dipole with this software I have now, it would be a good learning experience. The stuff you use is all simulation right, no in car test yet? I would think the back wave is the main variable, more so than the bumps around the baffle. 

My DCM home speakers featured in the avatar also share room between the mindrange and bass driver. It does have some partitioning MDF and polyfill though. It sounds to me like you need some in car FR tests to play with. Also post them up haha.


----------



## ErinH

thehatedguy said:


> The little AMT-types are marketed by Airborne and are made by Hygeia. I believe they also sell to Elco, Martin Logan, and Adam. The model number is RT-20021. You can take the face plates off and they get TINY. Meniscus has them, but that model isn't on their site. I went with them because they are TINY without the face plate, I never used an AMT-type tweeter, and they had symmetrical radiating surfaces...and I wanted to try something different than the Neo3 that I have had mixed feelings over. Jeff Bagby tested the big brother ones and they tested really well from what he says. A small dome like the Vifas would have been cheaper and covered a larger frequency range.
> 
> ºñ¼Íµç×ÓÓÐÏÞ¹«Ë¾
> 
> It becomes the 20021 with the face plate. That document is on the Solen webpage.
> 
> No pictures of the tweeters of the mids mounted...cause I haven't gotten that far yet. .


AMT drivers. Funny because I'm shopping another brand that uses this technology for a driver crossing at 800hz. Of course, like George said above these appear incredibly small. The ones I'm ordering are anything but.


----------



## thehatedguy

If I had a way to measure data I would...but I don't.

I was planning on putting some foam behind the driver to see what it does...I have some left over foam from my horns to play with- same stuff Geddes uses in his horns.

But don't take that it all sounds bad right now...just needs some tweaking and tuning once I get the other planars and tweeters in.

Erin, which AMTs are you looking at? Aurum Cantus has some, as does Mundorf, Ess has one. I think the Hygeia made ones can be had in much larger sizes...Meniscus and Solen have the RT-4001s which are larger than what I have, but not anywhere near the size of the ESS Great Heil. Truth be told I could have probably put the RT-4001s in the car with a little more work...I know would have gone in the center but might would have required a little more fab to do on the sides. The little ones pretty much dropped into the pods I made for the Scans. Maybe latter I will upsize to them.

And I think Hygeia makes a lot of ribbons and AMT for people. I have seen the omni ribbon they make in a couple high dollar commerical speakers. For a tiny tiny circular ribbon, look at their RT-1104. TINY. There is a guy on eBay selling them for $25. What is even more scary is the RM-8403 looks like a Neo 8 and the RM-8401 looks like the Monsoon planars.


----------



## bassfromspace

Are you guys testing the planars off-axis?


----------



## thehatedguy

The one in the center of my car is pretty much pointed at the top of the windshield, so it's pretty far off axis in that regard. The tweeter is right on top of it as close as I could get them together. I have the planar's long axis across the dash. Off axis is pretty good. I think the trick is crossing them over below where they start to narrow in output if you are way off axis. If you were on axis, you could take them pretty much out to 10-12k.


----------



## bassfromspace

thehatedguy said:


> The one in the center of my car is pretty much pointed at the top of the windshield, so it's pretty far off axis in that regard. The tweeter is right on top of it as close as I could get them together. I have the planar's long axis across the dash. Off axis is pretty good. I think the trick is crossing them over below where they start to narrow in output if you are way off axis. If you were on axis, you could take them pretty much out to 10-12k.


Good info. I ran my Neo 8's a bit off axis, with no tweeter, and I was satisfied. I've been wanting to try try them in the pillars, possibly with a tweet, but we'll see.

Are you running a dedicated midrange or midbass/neo-8/tweet?


----------



## cvjoint

I managed to find a test of an AMT speaker. Sufficit to say it looks kinda scary:
Scroll down to Mark and Daniel:
Zaph|Audio

Frequency response is simply unworkable, decay is very slow too, closer to a large cone, nonlinear distortion average at best. I don't know, not feeling it. I'm hoping other AMTs sound better. Can you guys recognize whether this is a rebadged product?


----------



## thehatedguy

I have the Neo-8S which is a little different than the "regular" Neo-8/PDRs. These have a similar diaphram construction to the Neo-10, twice the magnets of the other Neo-8s, and are 8 ohm. The resonance peak is lower at around 10k and drops off pretty fast after that whereas the other Neo-8s the peak is a little higher up and could be easier EQed flat to 20k.

I have these drivers paired to a SDX7 on the bottom side and the little Hygeia made Airborne marketed RT-2002 on the top side (I linked to the data sheet to the version without the face plate earlier).

http://www.solen.ca/pdf/airborne/rt20021.pdf

The tweeter/planar is passive- have a series crossover designed for them that has 12 dB slopes but using only a cap, coil, and resistor that has pretty flat phasing through out the XO region and really low group delay. As you know, no need for a zobel so parts count is really low. I just have to rob the parts from the existing passives and rearrange them....I haven't blown the tweeter up at 3.2k and it doesn't sound really stressed there, so should be golden at about 5k.


----------



## thehatedguy

Yeah that is a pretty not good test...I read it and it was in the back of my head the whole time.

As far as I can tell those guys have a curved AMT design which is different than what you normally find.

The ones I have, I doubt you will find any tests on...Meniscus sent a few pairs of the larger one out to some folks for testing and has reported that it has tested really well. I know Jeff Bagby has had a pair and said they tested really well. You will find reviews of speaker systems using this particular tweeter- ELAC in Germany uses them, Precide uses this brand, ADAM Audio uses this brand, and I am about 98% sure they are being used in the Martin Logan Electromotion and Motion lines of speakers (they went from the Neo-3 to these in their bottom 2 lines a few years back).

I know it's not what you were looking...but it's the best I can come up with right now...lol.



cvjoint said:


> I managed to find a test of an AMT speaker. Sufficit to say it looks kinda scary:
> Scroll down to Mark and Daniel:
> Zaph|Audio
> 
> Frequency response is simply unworkable, decay is very slow too, closer to a large cone, nonlinear distortion average at best. I don't know, not feeling it. I'm hoping other AMTs sound better. Can you guys recognize whether this is a rebadged product?


----------



## thehatedguy

And did everyone but me know that Martin Logan used the Neo 3 and Neo 8s in a lot of their speakers? Take a look at that Fresco set on evilbay.


----------



## ErinH

cvjoint said:


> I managed to find a test of an AMT speaker. Sufficit to say it looks kinda scary:
> Scroll down to Mark and Daniel:
> Zaph|Audio
> 
> Frequency response is simply unworkable, decay is very slow too, closer to a large cone, nonlinear distortion average at best. I don't know, not feeling it. I'm hoping other AMTs sound better. Can you guys recognize whether this is a rebadged product?


This is actually the brand I'm considering trying. A local producer deals M&D products and I've heard their entire line at his house. Excellent speakers. However the raw drivers may not be all that as the link above suggests. Hmmmm...


----------



## cvjoint

thehatedguy said:


> Yeah that is a pretty not good test...I read it and it was in the back of my head the whole time.
> 
> As far as I can tell those guys have a curved AMT design which is different than what you normally find.
> 
> The ones I have, I doubt you will find any tests on...Meniscus sent a few pairs of the larger one out to some folks for testing and has reported that it has tested really well. I know Jeff Bagby has had a pair and said they tested really well. You will find reviews of speaker systems using this particular tweeter- ELAC in Germany uses them, Precide uses this brand, ADAM Audio uses this brand, and I am about 98% sure they are being used in the Martin Logan Electromotion and Motion lines of speakers (they went from the Neo-3 to these in their bottom 2 lines a few years back).
> 
> I know it's not what you were looking...but it's the best I can come up with right now...lol.


No, that's pretty good. At least you know they are not the same exact speaker you want to use. I guess I'll keep my eyes pealed for some testing on these. The reviews generally annoy me if there is no bench test. 

I'm leaning more towards the Neo3 PDR for the next build as it is proven. Not that I think it performs better than the Vifa 3/4 I have. Both have similar distortion and decay performance, I just can't mount the deep Vifa over the Neo10 or I would to save some money.

I still don't know why Zaph never posted CSDs on the Neo10s. Maybe I'll email him about it. If they don't decay quicker than a standard 4" paper cone I'll stop thinking about them. 

The cool part about these Neo10s is that they have unusually low distortion from 500hz up to 1000hz, especially the third and higher order. Since my car acoustics require lots of EQ. 400hz to 1,000hz, it is likely BG planars will have lower distortion than cones. For the first time I may buy a set of speakers to cater to the car's interior. 

How do you feel about mounting a supertweeter on top of a BG element? I'm trying to figure a way not to cover the openings, like maybe overlap over the top inch of the frame only. 



thehatedguy said:


> And did everyone but me know that Martin Logan used the Neo 3 and Neo 8s in a lot of their speakers? Take a look at that Fresco set on evilbay.


Pretty much. :laugh:


----------



## thehatedguy

BG had a "coax" mounted Neo 3 on a Neo 10 on one of their speakers...Z92 and Z62 were done that way. And that was one of the ways I was going to go with my tweeter on the center.

I could have done a Neo 10 in the center, but man that thing's dispersion starts to get really narrow in the 2k range. I think you would NEED a Neo 3 with that puppy if you wanted to keep the dispersion wide. The Neo 3 is a badboy tweeter, I just wanted to test somethng out new before I sad "eff it" and do the Neo 3.

And call me late to the party on the ML thing. Hell, I might be slow but I get there eventually. Call me James May...lol.


----------



## cvjoint

thehatedguy said:


> BG had a "coax" mounted Neo 3 on a Neo 10 on one of their speakers...Z92 and Z62 were done that way. And that was one of the ways I was going to go with my tweeter on the center.
> 
> I could have done a Neo 10 in the center, but man that thing's dispersion starts to get really narrow in the 2k range. I think you would NEED a Neo 3 with that puppy if you wanted to keep the dispersion wide. The Neo 3 is a badboy tweeter, I just wanted to test somethng out new before I sad "eff it" and do the Neo 3.
> 
> And call me late to the party on the ML thing. Hell, I might be slow but I get there eventually. Call me James May...lol.


Captain Slow it is. I think I was on my second set of BGs when I found those Martin Logans. I guess we are true fans, signed up for a pair whether or not they were famous. 

BG overlaped them for cool points I think/truer point source. It looks really nice will all those smooth faceplates. I would think we have to fiberglass and sand for days to make something like that. 

I'm not so worried about dispersion but more about that jump in distortion right at 5khz for the Neo10. The other one is a resonance in the BG Neo3 PDR at 6khz. Not sure where I would cross them, somewhere between 4k and 10k. I would first check to see if 2nd order distortion jumps at 5khz in my car as well.

There is a test on Zaphs of the HiVi iso tweeter. The decay is very good indeed but the nonlinear distortion is not special. In fact, the BG elements are really front runners in this department, 3rd order distortion is as good as it gets. Maybe a lot of the laid back sound of these planars are for this reason. 

Have you looked at RAAls? I know they are enormous but last time I really squinted at their sheets. It seems the nonlinear distortion tests are done at very low output. I wouldn't be surprised if they were less than stellar compared to the BG which is slim and hell cheap.


----------



## thehatedguy

RAAL? I have a wife and two kids...lol.


----------



## cvjoint

In other related news I did more diggin' up on the SLS 6.5. Remember when I posted this? :




cvjoint said:


> I dug up more interesting info on the SLS 6.5. Check out the voice coil size:
> 39mm diamater
> 24mm long
> 4 layers
> 
> No look at the SLS 8
> 39 mm diameter
> 25mm long
> 2 layers
> 
> If the same wire is used I would imagine the SLS 6.5 coil could handle just as much power if not more than the 8. No wonder I couldn't get them to stress. The Seas Excel coils complain with much less juice on tap.
> Look at the ratings on the SLS 8:
> Long-term Max Power (IEC 18.3) 220 W
> Vs the 6.5:
> 100h RMS noise test (IEC) 150 W
> Long-term Max System Power
> (IEC) 50W
> 
> The ratings are thermal or mechanical whichever comes first from my understanding of the IEC rating. Hours of material with 6db crest factor. It could be the thermal rating is very very high on the 6.5, 220w or even more. When used with a 63hz high pass the mechanical limits increase by a lot but these tests don't show you that.
> 
> By comparison the B&C coil is:
> 44mm in diameter
> 12.5 long
> layers?
> 
> None of this is complete info but it is indicative of a very beefy coil. No wonder I can't get them to cry!


I think I can take this a step forward. A more careful look at the SLS 8 and 6.5 reveals that their motors are identical. Same outer diameter, same bumped backplate, same gap except for BL. But then it does make sense since the little guy is 4 ohm while the 8" is 8 ohm. Now go back to the layers on the voice coil. The 8" has half the layers. 

So what is going on? Me thinks Peerless uses the same motor for both. They take the coil on the 6.5 and remove half the layers leaving an 8 ohm coil in its place. Voila!

So what does this mean? Well, lots of good things. If the 8" has a long term power rating (IEC mind you) of 220w then the 6.5" can do a lot more. No wonder I am pushing over 300w realistically without a problem. This is as close as you can get to an indestructible 6.5" coil. Superb! Just another proof that the 6.5" is a serious midbass driver, the power compression is bound to be very low. I am now bumping my recommended power usage for these to at least 300w rms. So the spec sheet says 75W or something. No worries, those are tests limited by the suspension bottoming out under pure subwoofer use. We are using them as midbasses and the 63hz high pass will do wonders. I modeled them with 350w on tap for each, in pure IB with 20 cubic feet of space for each and they barely hit 9mm of excursion with a 24 db 63hz slope. The maximum excursion is well over 9mm so it's still playing no sweat at 350w, barely out of the linear range and most likely still with the coil intact. 

There is of course more fun to be had once you know the motors are the same. For example, our champion Npdang tested the SLS 8" on the Klippel. We can make use of the LE and BL plots to learn about our 6.5":

http://www.diymobileaudio.com/forum/member-reviews-product-comparisons/9060-8-midbass-comparison.html

Also notice here that the XLS8" seems to have the same motor as well. The difference between the XLS8" SLS8" and SLS 6.5" is mostly in the baskets and suspension. 

The difference between the xls and sls is most likely a better centered suspension, better diaphragm strength/weight ratio, and a more vented basket. The BL and inductance are identical. So the might XLS was better, but only by a bit. If only they centered the suspension better on the SLS the other differneces would be negligible. 

Moving on to 6.5 vs 8 SLS comparison. We can now see that the inductance is indeed really low and more importantly and very linear over stroke. The aluminum shorting rings seem to work like a charm. Good job Peerless. On the 6.5 is probably really close to the rated 1.5mh I would think since the coil layers are doubled.

The BL looks good too. .82% BL distortion point is probably 7.5mm or so and the .70 more commonly used by the manufacturers is around 8.5mm, just like the white sheet.

I think this is good evidence that the motor on the Peerless does have a lot more linearity than the B&C. We're looking at about 40% more stroke I would say. 

The suspension remains a mystery of course until we test the 6.5" on the Klippel. Looking at the SLS 8" it doesn't look very promising but then again they do look a lot different to me. The 6.5 is beefy like a sub whereas the 8 is somewhere between a sub and a 2 way woofer.


----------



## cvjoint

thehatedguy said:


> RAAL? I have a wife and two kids...lol.


Could be worse, you could have two wives and a kid. :sultan:


----------



## thehatedguy

The extra nookie would in no way make up for another time of the month and more mood swings. That makes my head hurt thinking about it.



cvjoint said:


> Could be worse, you could have two wives and a kid. :sultan:


----------



## thehatedguy

Dude...you are so making me want to try those SLS6s.

I don't know of they would physically fit.


----------



## cvjoint

thehatedguy said:


> The extra nookie would in no way make up for another time of the month and more mood swings. That makes my head hurt thinking about it.


No worries, they coordinate on the time of the month, kinda freaky if you ask me. The trick is to separate them, maybe different houses I don't know how strong that nature link is. 

If I find good drivers I do like to share. It doesn't always go that well. For example you won't hear me rave about the Vifa ring radiator.

BTW Peerless uses the same motor on the SLS 6.5, 8, and *10!* At that point they do specify a larger magnet on what appears to be the same top and bottom plate for the 12," it looks funky. This is what we call economies of scale haha. No wonder the surrounds on the larger brothers are more tame, there is no need to step up the surround if the motor gets recycled.


----------



## cvjoint

Apparently Zaph does not have the CSD plot for the Neo10, he didn't think it's worth the trouble. I'm trying to see if he can give me some pointers on the usefulness of CSDs. I pitched the same counterexample I gave earlier in the thread. Now waiting patiently, not.


----------



## 24th-Alchemist

I'm getting tired of my own posts, nevertheless I'd like to offer a few last comments on cumulative spectral decays (CSDs). Then I'd like to document some time-domain simulations that this thread inspired me to try. (I did the work so I may as well post it).

======================================================

_cvjoint_ if you here back from Zaph about CSDs I hope you'll post a summary of what you learn.

It seems to me that CSDs can be used to see non-linearities, particularly those in the form of non-linearly stored energy.

I think the CSDs from simulations of linear systems that I posted previously establish at least three trends that can be used to better understand the performance (non-linearities) of real drivers:

For a flat frequency response, lower frequencies in a CSD tend to decay away more slowly than higher frequencies;
If there is a frequency response peak, we can see the consequences of that FR peak in the CSD as a relatively slower decay around the peaking frequency (assuming the CSD is properly generated);
All other things being equal, a driver with a wider bandwidth exibits a slightly faster decay in its CSD at all frequencies.

Based on trend (1) we would expect a speaker with a flat frequency response (FR) to have CSD that decays more rapidly as frequency increases. If there were some frequency _f0_ around which decay slowed as frequency increased, we could use trend (2) to try and understand the discrepancy. If the speaker had a FR peak around _f0_, then the slower decay along _f0_ in the CSD would be an expected consequence of the FR peak, and would thus represent a linear distortion that could presumably be "EQ'ed away". If on the other hand the FR were flat around _f0_, then the slowed decay around _f0_ in the CSD would represent a non-linear distortion -- something difficult if not impossible to correct with EQ. Lastly, if one speaker has a well-behaved CSD that decays more rapidly than another speaker that also has a well-behaved CSD, trend (3) suggests that the faster decaying CSD doesn't automatically imply a better driver if the slower decay is due to lower bandwidth and the drivers are intended for lower frequency applications where the audio signal is already "slow" due to low-passing in a crossover for example.

The overarching idea here is that theoretically for a linear driver a CSD adds no information that isn't already contained in the FR, because both the CSD and FR can be obtained from the same impulse response. At best, for a linear driver the CSD provides an alternative to the FR for looking at speaker characteristics. But an alternative such as a CSD is questionable IMO because of the distortion introduced by the time-windowing component of generating a CSD. Nevertheless in the "real world" a CSD can apparently have some value because if a driver is non-linear (and they all are), the FR and CSD will presumably not correspond in the way we would expect for a linear driver, and any differences from the ideal correspondence can be used to glean insight into the non-linear attributes of a driver. Related to this, a primary purpose of me performing the CSD simulations was to try and get a feel for what is expected in the ideal (linear case) so I could better understand deviations in the real world. To be honest though, sometimes I feel like the CSD simulations I posted generate more confusion and questions than answers (myself included). On the other hand, hopefully the simulations made some of us think, and after having some time to digest things and consider other sources perhaps we'll end up with an overall improvement in our understanding.

========================================================

Now I'd like to post some time-domain simulations relating to the past discussions about speaker inductance (_Le_) and its affect on woofer speed, transient response, frequency response curves, and practical applications.

There have been several comments about _Le_ in this thread, as well as related ideas from a thread referenced by _cvjoint_,

http://www.diymobileaudio.com/forum/car-audio-truth-myths-industry-dogma/87371-fast-bass-slow-bass-myth-vs-fact-2.html;​
and additionally sources referenced in that thread,​
SoundStage! Max dB - Fast Bass, Slow Bass - Myth vs. Fact (06/1999),

http://www.stereointegrity.com/Files/WooferSpeed.pdf;​
and other threads referenced within that thread,​
http://www.diymobileaudio.com/forum/how-articles-provided-our-members/30-transient-response-stored-energy.html,

http://www.diymobileaudio.com/forum/how-articles-provided-our-members/9579-loudspeaker-inductance.html.​
The first simulation I performed attempts to examine the effects of _Le_ and _Q_ on transient response. It is intended to address some of the main issues discussed in the thread http://www.diymobileaudio.com/forum/car-audio-truth-myths-industry-dogma/87371-fast-bass-slow-bass-myth-vs-fact-2.html and the "Adire paper" http://www.stereointegrity.com/Files/WooferSpeed.pdf. The two main issues, as I read things, were whether high _Le_ was bad because it "slowed" woofer response and whether _Q_ was the real dominating factor in transient response (for woofers at least).

The first simulation is centered around a basic midbass speaker model: a woofer with a _Qts = .707, fc = 80 Hz_ (12 dB/oct Butterworth highpass), and an _Le / Re_ combination such that the woofer has a 6 dB/oct low-pass roll-off starting at 300 Hz.​From there, the woofer is modified in one or both of two ways:
To examine the effects of lower _Le_, the _Le / Re_ ratio is changed such that the low-pass roll-off moves up from 300 Hz to 2.5 kHz (still at 6 dB/oct),
To examine the effects of _Q_, the high-pass _Q_ is raised from .707 to 3.

The plot below shows simulated responses (blue traces) to a 0.5 ms pulse (gray traces) under all possible combinations of the above two woofer modifications.










To my eye, the simulations above are in agreement with what I see as the main contention of the "Adire paper" (http://www.stereointegrity.com/Files/WooferSpeed.pdf), namely that a lower _Le_ (higher low-pass cut-off) results in a "faster" transient response. To see this, compare the response in the upper left (UL), (high _Le_; roll-off at 300 Hz), with the one in the upper right (UR), (low _Le_; roll-off at 2.5 kHz): in the UL the transient is too slow and cannot keep pace with the pulse; in the UR however the response much more closely follows the pulse.

Note that the title of the Adire paper is "_Woofer Speed_" and furthermore that in the paper is is said


> What is transient response? Simply a measure of how fast the driver can respond to the input signal


.
So if the definition of "transient response" is restricted to woofer speed, then the contentions in the Adire paper seem valid.

There are however at least two problems with this. First, there is more to transient response than speed. This is pointed out in the thread referenced by _cvjoint_: http://www.diymobileaudio.com/forum/car-audio-truth-myths-industry-dogma/87371-fast-bass-slow-bass-myth-vs-fact-2.html. To see this in the simulation plots above, compare the response in the UL to the one in the lower left (LL). In going from the UL to LL, the modeled _Le_ remains fixed (300 Hz break frequency), but the high-pass _Q_ changes from .7 to 3, and we see the increase in oscillations as the response more slowly decays away (consequence of higher _Q_). In the lower right response _Q_ is changed from .7 to 3 and simultaneously _Le_ changed so the low-pass break frequency moves up from 300 Hz to 2.5 kHz (fixed 6 dB/oct roll-off)). Here we see both the increased speed as well as longer, more oscillatory decay. 

Is it fair to say _Q_ "dominates" the transient response (as in said in http://www.diymobileaudio.com/forum/car-audio-truth-myths-industry-dogma/87371-fast-bass-slow-bass-myth-vs-fact-2.html)? Theoretically perhaps it isn't, but practically speaking I think it is fair to say, because if we have a speaker with a low frequency roll-off of 300 Hz, we should never expect it to faithfully reproduce something such as a 0.5 ms pulse in the first place (the 0.5 ms pulse has significant frequency content well above 300 Hz). Said another way -- and this is a second problem with the Adire viewpoint -- if a driver has a relatively flat frequency response up to say, 2.5 kHz, then it cannot have an _Le_ so large that it is "too slow" to properly follow content below, say, 1 kHz or maybe even 2kHz in the time-domain. An inference I draw from simulations such as the one above is that an honest specification of bandwidth almost renders _Le_ moot as it pertains to speed. If a subwoofer for example is intended to play up to 100 Hz and it has an _Le_ such that it rolls off at 200 Hz or 2 kHz then both should do well for 100 Hz because a 100 Hz band-limitted signal is slow to begin with. (And I post some simulations below that address this more directly). (Note though that non-linear distortion due to changes in _Le_, which might be more significant for a larger _Le_, may be important -- but that's a different issue from speed).

To examine the relationship between _Le_ and bandwidth a little further in a more real-world scenario, I modeled a fourth order Linkwiz-Riley (LR4) crossover between midbass and midrange at 250 Hz under two conditions:
midbass rolls off at 300 Hz (high _Le_ woofer 1);
midbass has "full" 2.5 kHz bandwidth (lower _Le_ woofer 2).

Below are the time-domain results for passing a tone-burst centered at the crossover frequency (250 Hz) through the crossover. The low-pass (midbass) and high-pass (midrange) components are summed to get the overall response. There are three cases (described below), and since each case had a different phase, I time aligned the peaks of the responses for easier comparison.










The black trace is what happens when the 250 Hz tone burst is passed with no crossover though the wide bandwidth, "fast", low _Le_ woofer (woofer 2 from above: _Q=.7, fc=80 Hz 12 dB/oct Hp; 2.5 kHz 6 dB/oct LP due to Le_). The black trace is the "best-case" response.

The blue trace is what happens when woofer 2 from above is used as both the midbass (MB) and midrange (MR) driver with an LR4 crossover at 250 Hz between. (The reason for using the same woofer for both MB and MR is to isolate the effects of the crossover). The outputs of the MB and MR are summed to get the overall response shown in blue.

The green trace is what happens in the same case as the blue trace, except that with the green the MB woofer begins to roll off at 300 Hz instead of 2.5 kHz (high _Le_ "slow" woofer 1 from above). (I.e. we have the 24 dB/oct 250 Hz lowpass of the LR4 and an additional 6 dB/oct LP at 300 Hz due to the woofer _Le_). 

The blue dashed trace is the difference between the black trace (ideal "best-case" response) and blue trace (LR4 crossover). In other words, adding the blue dashed to the black yields the blue; the blue dashed is the "interference" superimposed on the black to yield the blue.

Similarly for the green dashed between the green and black traces.

So, are the differences audible?

To examine this I converted the traces to waveforms and listened on headphones. For me, no, the differences were not audible. The sound is like a blip, and I cannot tell the difference among the three.

However, the phases of the two woofers in a LR-4 crossover are aligned, and in order to further explore issues of phasing that are somewhat related to the integration and phase issues described qualitatively in the SoundStage! Max dB - Fast Bass, Slow Bass - Myth vs. Fact (06/1999) reference, I tried one last simulation.

Instead of the tone burst, which is just a pure sinusoid with an amplitude envelope, I ran the same simulation just described, except I changed the input from the tone burst to the 0.5 ms pulse from the first simulation. The results are shown below.










To summarize (same woofer scenario as previously),
the black trace is the "best-case" response of the 0.5 ms pulse played by the low _Le_ woofer 2 with no crossover (_Q=.7, fc=80 Hz 12 dB/oct HP; 2.5 kHz 6 dB/oct LP_);
the blue trace is low _Le_ woofer 2 for both MB and MR with LR4 crossover at 250 Hz between;
green trace is same as blue accept MB woofer is woofer 1 and starts to roll off at 300 Hz instead of 2.5 kHz.

It is interesting to recall that the frequency magnitude of the summed output of an LR-4 crossover is _flat_; therefore the difference between the black and blue responses is due solely to the phase contribution of the crossover and not frequency magnitude, because the frequency magnitudes of the black and blue are identical. (And just to be sure I double checked this by simulating the LR-4 crossover as a second order all pass, _Q=.5, fc=250 Hz_, and indeed I got a trace identical to the blue trace in the figure that is obtained by summing the LR-4 crossover outputs). The green trace is similar to the blue except, as before, for the green trace the MB woofer starts to roll off at 300 Hz instead of 2.5 kHz, just above the 250 Hz LP for the LR-4 crossover.

In this case I could detect audible differences between the black and blue traces, but not between the blue and green. Although the signals look drastically different, the differences I perceived listening on headphones were minimal. (And I listened with no less than four DACs -- one from a PC, one form a laptop, one single-ended that I built and one differential with no DC blocking caps that I built -- and two sets of headphones -- Sony MDR-v700 and a Monster in ear -- with qualitatively similar results in all situations).

So my take away from this last simulation is that the crossover introduces minimally audible distortion (at least when listening to this 0.5 ms click), but the slowness due to an _Le_ roll-off barely above the intended bandwidth was inaudible (in this case). Also, in comparing the blue and green traces -- larger _Le_ causing the difference -- we can see they're very close even though the MB woofer contributing to the green is rolling off a mere 1/4 octave above its intended bandwidth of 250 Hz. Of course, if we have a woofer with a high _Le_, that _Le_ comes into play in that it forces use of a LP crossover in order to keep the woofer playing inside its useable bandwidth.

Most interesting to me is how drastically different the black and blue traces are versus how minimal the sound difference is. Both are clicks, the black just seems to have a higher pitch when carefully compared with the blue or green.

Note that the off axis responses of the woofers are not considered in these simulations and of course in a car there are a multitude of additional contributing factors.

=========================================================

_cvjoint_ thank you for your responses to my inquiries about the SLS 7in. What you wrote seemed reasonable.

========================================================

More recently _cvjoint_ you have provided some compelling arguments in favor of the SLS 7 and I'm becoming tempted. I will mention that I run CDT M6 in 0.25 cu ft sealed in my doors (PDF specs here, advertisement pics here) and it seems to me CDT M6+, ES-06+ and QES-680 are all the SLS P830946 in various modified forms. A couple of years ago, after I blew my first set of M6's, I called CDT and asked which would be better for pure 60-250 Hz midbass sealed, M6 or M6+, and they said the M6, not the M6+ (the M6+ looks like the peerless). Puzzling.

=======================================================

_cvjoint_ thank you for this great thread, thank you for your insight and your data collection. A refreshing reprieve from the bulk of threads on this forum.


----------



## cvjoint

Superb post, this one is probably near the top of most useful posts. I will surely go back to it from time to time for reference. Luckily this time everything is clearly understood for me, I think. The three points you listed follow very nicely from the CSD experiments and I understand now these are what I previously referred to as CSD artifacts. Without knowing these no proper inference can be made. 

It seems to be that because of difficulties of drawing decay information from CSDs mostfolks give up on them altogether. This brings me to the points Zaph made in his emails. 

He has been very straightforward in discouraging the use of CSDs as anything more than another way to show information contained in the FR. Note for example halfway into the "tidbits" section his comparison of a poly and metal cone before and after the implementation of a low pass filter. 

I told him I am trying to use his CSDs for the purpose of comparing decay of different technologies. Look at the small group CSD comparison for example. There are domes and cones there. It appears at first that the domes decay faster than the cones. Zaph pointed out that their frequency response drops quicker which has a direct impact on CSD much like his tidbits example. Good point. This is the same as point 3 that you made I think or simply a lower fundamental output level. Either way, point well made I can't use the CSDs in the way I was hoping. 

Miscellaneous thoughts of mine:

*It would be nice to know if the Dayton Omnimic FR check box does away with point 2 related artifacts. 
*point 1,3 imply CSDs are never an absolute type measurement.
*How about relative comparisons? If the following conditions are met, would CSDs give us a proper decay comparison:
FR flattened out (maybe Dayton Omnimic FR Equalize checked), same window, same axis markers. I guess the biggest challenge is to EQ. away the linear distortion perfectly before applying an exact CSD to both drivers. 


In the LE and speed simulations aren't these points still valid? You are modeling LE as a rolloff, and therefore changing the bandwidth of the driver. If impulse response give artifacts related to rolloff, your point 3, how do you know you are really simulating the LE effect? 

The ES+ drivers are interesting, haven't seen them beofore. They even seem to have the exact type of inductance treatment but a pole vent


----------



## cvjoint

SLS 6.5 blown out of the water:

http://www.diymobileaudio.com/forum/1401109-post39.html

Looks like 11mm of motor throw and 8.5mm of suspension throw using the stricter Xmax limits. This can easily outpace the SLS in every category. By comparison the SLS only has 7.5mm of motor throw. Regardless of how good the suspension is xmax will be motor limited at 7.5mm, but there are good chances it can't do that based on previous Peerless klippel tests, suspensions lag behind motors in 99% of the Peerless drivers. The Exodus is at 8.5mm no matter what, so more throw guaranteed.

I can't believe the difference between the CSS, Exodus and Adire 7" drivers, not alike at all. 

Now where exactly do I get 10mm of mounting depth from?

EDIT: bought them. I would have shot myself in the face if they cleared out and I didn't have a pair. I now have to reengineer the window stopper for an S2k to pull this off. I will also have to trim the basket to make it truncated. Wish me luck.

EDIT2: Got my hands on the Voice Coil magazine Klippel results on the Anarchy. The motor is slightly worse in these tests, given to a higher offset (presumably production variance). Xmax limit due to motor distortion is 8.5mm at 82% down on the BL graph, and 10mm 75% down on the CMS graph. So the suspension is better but the motor is worse, either way 8.5mm xmax just like the manufactuer's test, either way better than the SLS. The inductance however is not as nice, having a standard downward sloping pattern. No shorting rings at all?


----------



## thehatedguy

George, I haven't forgotten that PM you sent me the other day...doing research before I can make even an educated guess...lol.

But let me ask you this (which somewhat relates to the PM), how much of that throw are you going to be using or even needing? Would you need it crossed at 50 or 80 hertz?

Oh, the Neo-8Ss rock.


----------



## 24th-Alchemist

> *It would be nice to know if the Dayton Omnimic FR check box does away with point 2 related artifacts.


Is there documentation that describes what the check-box does? Generally speaking I'm skeptical of relying on such things without thorough testing in addition to reading function descriptions.



> *point 1,3 imply CSDs are never an absolute type measurement.


I don't think so. Consider two drivers where one has a FR that is everywhere 6 dB above another. Each driver receivers the same input from an amp. We can look at the CSDs and talk about absolute energy, absolute decay, etc. In such a case the driver with the higher FR will have proportionally more absolute energy at any time (e.g. ~2x for 6 dB on the FR), but the _rate_ of decay of energy in terms of % per time interval would be identical due to their identical bandwidths. We can compare both absolutely and relatively. In this example the driver with the +6 dB FR is just more efficient at converting energy from an amp into sound energy. Perhaps the question is what type of comparison is more relevant, relative or absolute? 

It seems to me that usually relative comparisons are more important, unless for example a driver has both low sensitivity and low power handling or high distortion at high power and sufficient clean output is a concern, otherwise just compare relatively and provide the power required for desired output.



> *How about relative comparisons? If the following conditions are met, would CSDs give us a proper decay comparison:
> FR flattened out (maybe Dayton Omnimic FR Equalize checked), same window, same axis markers. I guess the biggest challenge is to EQ. away the linear distortion perfectly before applying an exact CSD to both drivers.


Broadly speaking this seems reasonable. If the FRs were nearly but not perfectly flat I'm not sure that small FR variances would significantly affect a CSD comparison -- one way to get a qualitative handle on the threshold where FR variability becomes significant for CSDs could be with CSD simulations.



> In the LE and speed simulations aren't these points still valid? You are modeling LE as a rolloff, and therefore changing the bandwidth of the driver. If impulse response give artifacts related to rolloff, your point 3, how do you know you are really simulating the LE effect?


Ultimately I'm simulating the affect of bandwidth as you stated. But _Le_ affects bandwidth -- for example, if _Le_ increases, bandwidth decreases, and it seems to me that I am therefore simulating the affect of _Le_ (when it acts linearly). I have read that _Le_ typically doesn't yield a 6 dB/oct roll-off due to "eddy current losses", but I will also say that I recently modeled my mids and tweets as as 2nd order HP and 1st order LP due to _Re / Le_ -- just like the model in my previous post -- and then I measured the phase responses of my speakers, and both midrange and tweets were in very very good agreement with what is predicted by simulations that use the aforementioned linear model of the _Re / Le_ effects. (I would like to post these results in a different thread sometime -- we'll see if there's time).

In other words, anything that changes bandwidth would have the effects shown in my previous post. But in my models I held everything but _Q_ and _Le_ constant to isolate their effects. In a real speaker it might be difficult to prove unequivocally that a change in bandwidth is due to _Le_, but in a model there is control.


----------



## 24th-Alchemist

Referring to the Exodus Anarchy: 



> EDIT: bought them.


So can we look forward to measurements similar to those you posted previously for the 6.5-inch SLS?


----------



## fish

Jason,

Would you mind sharing a bit more about the Neo8-S? I'm very intrigued by these. How low do you have them crossed?


----------



## cvjoint

thehatedguy said:


> George, I haven't forgotten that PM you sent me the other day...doing research before I can make even an educated guess...lol.
> 
> But let me ask you this (which somewhat relates to the PM), how much of that throw are you going to be using or even needing? Would you need it crossed at 50 or 80 hertz?
> 
> Oh, the Neo-8Ss rock.


Ok, no rush, I'm rather broke nowadays anyway. 

I was looking at other subwoofer replacements to try out:

1.Vifa NE 12" are first light (6.5lbs), then they have a good amount of throw 11.9mm Klippel verified and they only cost $115 bucks. That basket is also superb, perfect for IB mounting. The inductance is cubed a little, good enough for government duty and it is low.

2. TC Sounds Epic 12" , best part is throw. Looking at the Eclipse SW8200 Klippel on this site, that TC suspension is going to be the bottleneck with only about 16mm throw, if they are anything alike. The motor I'm not worried about, the TC2+ is good for over 20mm. Bad part is weight at 22lbs but at least they fit in the S2000 with no mods. LE seems good, probably like the Eclipse but higher.

How much of the throw would I be using? Well, I can upgrade to the old Clarion GH 1550w monoblock. It's dirt cheap, efficient, and fits footprint wise. At either 1.33ohm or 2.66ohm (4 or 8 ohm subs) they should move the TC subs to at least 20mm. It would still be likely over the true suspension 10% point, and 10% is a lot of distortion. The crosspoint is 63hz 24db.






24th-Alchemist said:


> Is there documentation that describes what the check-box does? Generally speaking I'm skeptical of relying on such things without thorough testing in addition to reading function descriptions.
> 
> 
> 
> I don't think so. Consider two drivers where one has a FR that is everywhere 6 dB above another. Each driver receivers the same input from an amp. We can look at the CSDs and talk about absolute energy, absolute decay, etc. In such a case the driver with the higher FR will have proportionally more absolute energy at any time (e.g. ~2x for 6 dB on the FR), but the _rate_ of decay of energy in terms of % per time interval would be identical due to their identical bandwidths. We can compare both absolutely and relatively. In this example the driver with the +6 dB FR is just more efficient at converting energy from an amp into sound energy. Perhaps the question is what type of comparison is more relevant, relative or absolute?
> 
> It seems to me that usually relative comparisons are more important, unless for example a driver has both low sensitivity and low power handling or high distortion at high power and sufficient clean output is a concern, otherwise just compare relatively and provide the power required for desired output.
> 
> 
> 
> Broadly speaking this seems reasonable. If the FRs were nearly but not perfectly flat I'm not sure that small FR variances would significantly affect a CSD comparison -- one way to get a qualitative handle on the threshold where FR variability becomes significant for CSDs could be with CSD simulations.
> 
> 
> 
> Ultimately I'm simulating the affect of bandwidth as you stated. But _Le_ affects bandwidth -- for example, if _Le_ increases, bandwidth decreases, and it seems to me that I am therefore simulating the affect of _Le_ (when it acts linearly). I have read that _Le_ typically doesn't yield a 6 dB/oct roll-off due to "eddy current losses", but I will also say that I recently modeled my mids and tweets as as 2nd order HP and 1st order LP due to _Re / Le_ -- just like the model in my previous post -- and then I measured the phase responses of my speakers, and both midrange and tweets were in very very good agreement with what is predicted by simulations that use the aforementioned linear model of the _Re / Le_ effects. (I would like to post these results in a different thread sometime -- we'll see if there's time).
> 
> In other words, anything that changes bandwidth would have the effects shown in my previous post. But in my models I held everything but _Q_ and _Le_ constant to isolate their effects. In a real speaker it might be difficult to prove unequivocally that a change in bandwidth is due to _Le_, but in a model there is control.


Great post as usual. I seem to forget there is the option of simulating impulse responses as a basis. From there I guess any deviation can be looked at as absolute. There is no useful manual info on the EQ. function. Time to ask PE. 

Am I right in saying that you believe higher bandwidth speaker have quicker decay not only when tested with an impulse response but in reality as well? I can see how the bandwidth can affect CSDs now, but not really sure bandwidth affects decay in itself. 



24th-Alchemist said:


> Referring to the Exodus Anarchy:
> 
> 
> 
> So can we look forward to measurements similar to those you posted previously for the 6.5-inch SLS?


Really split on this Exodus. The part that puts me off is the apparent lack of shorting rings. The inductance is lower than the SLS which helps with deviations but it's still very asymetrical and standard looking. It does however model better and seems to have more throw. I would have to truncate the basket and get rid of the window stopper to test it. Will keep you posted. 

I looked through maybe 30 tests in Voice Coil Mag. today. My favorite 7" midbass has to be the Scan Illuminator. 10mm of throw by suspension and motor with a ridiculously perfect inductance curve. It's also neo and light but it's deeper than the Exodus by quite a bit. The depth and price are the only weaknesses for this guy.


----------



## t3sn4f2

cvjoint said:


> I looked through maybe 30 tests in Voice Coil Mag. today. My favorite 7" midbass has to be the Scan Illuminator. 10mm of throw by suspension and motor with a ridiculously perfect inductance curve. It's also neo and light but it's deeper than the Exodus by quite a bit. The depth and price are the only weaknesses for this guy.


Does the AL version fair as well? I'd be nice not to have to deal with that paper cone in a car door install.


----------



## vactor

say, what are our current crossover settings? i was also wondering what your impression of the vifa tweeter were. i read the thread again and may have missed those points. kickass install. my (lamer) one should be completed early next week. w00t


----------



## cvjoint

vactor said:


> say, what are our current crossover settings? i was also wondering what your impression of the vifa tweeter were. i read the thread again and may have missed those points. kickass install. my (lamer) one should be completed early next week. w00t


The Vifa's are fantastic. The job of a supertweeter is to first have a smooth frequency response, second good dispersion, third lots of output, and far last good nonlinear distortion. The FR is smoother than the more expensive Scan Speak, dispersion is good simply given it's small dome size and again better than the 3/4 scan, great output is insured by having a high sensitivity, check, and a large coil to soak up power, check. Distortion performance is not all that important and maybe it's not as good as the Scan if you cross at 2khz, but that's not my application so it shines only where it has to. 

People often say sub 80hz is the easiest to get in a car. I think it's over 5khz that's is the easiest. If you have the Vifa's mildly on axis you don't even need EQ., it's the only driver that gets next to no attention. It's great out of the box, has a sealed chamber, just has to be aimed properly and the job is done. 

I cross mine at 6.3khz but any crosspoint 4khz and up is just as easy. If you cross lower, then the 1" domes and the BG Neo3 start making more sense. 



t3sn4f2 said:


> Does the AL version fair as well? I'd be nice not to have to deal with that paper cone in a car door install.


That was the aluminum version. It seems to have some distortion issues around 3khz due to cone breakup, ideally you want to cross at 1.8khz is what the article says but higher is OK. 

These Illuminators are strictly better than the Revs when paper is compared to paper. The nonlinear distortion is barely any different but the motor is twice as strong. That's why I would like to see Zaph test drivers at higher output levels to showcase the motor quality, that is the heart of the speaker.


----------



## thehatedguy

The ones in the door are at 400 hz 24 dB/oct. The one in the center is higher than that...don't remember exactly off of the top of my head. They go to about 5k on the high side.

I haven't retuned or messed with the MS-8 since putting them in so they are still playing through the old crossover and EQ settings.



fish said:


> Jason,
> 
> Would you mind sharing a bit more about the Neo8-S? I'm very intrigued by these. How low do you have them crossed?


----------



## bassfromspace

thehatedguy said:


> The ones in the door are at 400 hz 24 dB/oct. The one in the center is higher than that...don't remember exactly off of the top of my head. They go to about 5k on the high side.
> 
> I haven't retuned or messed with the MS-8 since putting them in so they are still playing through the old crossover and EQ settings.


Enclosed or IB?


----------



## thehatedguy

IB as of now.


----------



## BowDown

My setup:

xtant 10" 20hz -> 56hz [12db]
SLS 6.5's are from 56hz [12db] -> 710hz [24db]
neo8 PDR's from 710hz [24db] -> 4khz [18db]
neo3's from 4khz [18db] -> 20khz


----------



## cvjoint

TC Sounds doesn't have the Klippel report for the Epic subs. Anybody know if these or the TC 1000 ever got tested anywhere?


----------



## cvjoint

Another victory by Scan:

http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/113842-technical-comparison-12m-hat-l4-faital-pro-4-my-take.html

The Faital is likely a worse performer than the Scan, and the Exodus is likely a worse performer than the Scan Illuminator 7". I hated it when the seriously expensive driver wins but it is what it is. 

The real question is BG neo10 vs Revelator Array.


----------



## thehatedguy

Revelator array if you have the money for it.

Though the Neo-10 can play higher.


----------



## fight4life28

Very nice setup you got there. Wish i had the money and the skill to get something like that too.


----------



## thehatedguy

If you go Neo-10s, I know a guy who can get them for about $45 off of catalog price at PE. And shipping would mess up the price break this time.

And if you could do the Neo-10s dipole, you are looking at the radiating area of about an 8.


----------



## cvjoint

thehatedguy said:


> If you go Neo-10s, I know a guy who can get them for about $45 off of catalog price at PE. And shipping would mess up the price break this time.
> 
> And if you could do the Neo-10s dipole, you are looking at the radiating area of about an 8.


Nice. I'm trying to buy a house at the moment so my assets are frozen so to say. As soon as this is done I'll lay the cash for a neo 10, the scans are way too much. We're talking about $1500 for the line array!  The neo 10 would be sealed, by the book, two inches of clearance behind it and everything. I'm actually going to try to absorb the rear wave completely. I have deflex behind 1 inch of open cell foam. 

We're looking at these tests in the future:

SLS vs. Exodus Anarchy within a month's time

Faital line array vs. Neo10 2 months from now

AE IB12 vs. Vifa NE12" 3 months from now


I'm thinking of running some tests on the SLS vs Anarchy without 1/6 octave smoothing, just pure non smoothed data. The SLS is already to low distortion (below 1%). I don't see how else we're going to see a difference between the two. I can also test without a 63hz high pass but that's not really fitting for the midbass application. 

Any ideas for the midbass comparison? What would you like to see?


----------



## Ultimateherts

thehatedguy said:


> If you go Neo-10s, I know a guy who can get them for about $45 off of catalog price at PE. And shipping would mess up the price break this time.
> 
> And if you could do the Neo-10s dipole, you are looking at the radiating area of about an 8.


Now you make wanna spend more cash...


----------



## cvjoint

Almost forgot this future comparison:

Vifa NE tweeter vs. BG Neo 3 PDR or Airbone RT-20021 AMT tweeter. Haven't made up my mind about which advanced tech. tweeter is going to challenge the Vifa.

I could actually make some better use of the windowing on the CSD tool to remove reflections for tweeters, especially for supertweeters. That's going to give us a better idea about the decay qualities.


----------



## cvjoint

*Exodus Anarchy* the SLS competitor





































Build quality impressions

The basket looks like this Wavecor:
WF182BD03_04

Regardless, it's very well vented even under the spider. The voicecoil former is vented as well. If that's not enough there is a vented pole piece. I'm pretty happy with the basket choice, doesn't get much better. 

The cone is properly built, not a lot of excess glue, smudges, or lifted ends. This is properly crafted compared to the CSS.

There seems to be a tube on the voicecoil leads. It either keeps them from breaking or from audibly hitting the cone I imagine. 

The motor itself is massive. This will easily trump the SLS but it may also not fit. 

A gasket is included and it is permanently attached to the basket. That's very nice for this price point, actually all of it is. 


All in all this gets an A. To get an A+ I would have liked to see a neo motor to save weight and further help with venting. The basket is probably not a unique one but it does everything right. The aluminum cone is a great simple choice for a midbass. 

The one thing the Exodus Anarchy promises that no other XBL2 7" has is a suspension that matches the motor thrust. Before the Anarchy no XBL driver ever exceeded an excursion of 4mm without getting highly nonlinear. 

CSS 4mm
RE XXX 3mm
Extremis 3.5

Klippel results show 8.5mm or more of clean excursion from the suspension on this guy. It's hard to see how they managed that since the spider and surround are not as beefy as one would guess for this kind of linearity. This enables the Anarchy to maintain loads of surface area at the same time. Bravo Exodus.

The shipping box was again questionable. There is a foam piece that keeps the surround from getting bent out of shape. The motor and everything else is protected simply by the cardboard. At 7 plus lbs that's pretty risky. Either way mine made it ok.


----------



## cvjoint

Selling the subs, not sure what I'll get to replace them yet:

http://www.diymobileaudio.com/forum/car-audio-classifieds/114500-fs-acoustic-elegance-ib12a-8-12-subwoofers-%24125-shipped.html


----------



## SSSnake

Why?


----------



## thehatedguy

Fugger.


----------



## cvjoint

SSSnake said:


> Why?


Because I have an itch, and the only thing that helps is more cowbel, no kidding, new drivers!

I'm going crazy and replacing everything. Time to incorporate the 3 dozen or so Klippel and thd tests I've been glossing over since I first built this car. With this Omnimic setup it should be easy to double check that I'm not downgrading.

Look at it this way guys, more tests comming up!

I just called Vin to pick up my Omnimic and sealed box sub. I want to test the AE and the SLS a lot before they get replaced. Should be fun!


----------



## ErinH

cvjoint said:


> Because I have an itch, and the only thing that helps is more cowbel, no kidding, new drivers!
> 
> I'm going crazy and replacing everything. Time to incorporate the 3 dozen or so Klippel and thd tests I've been glossing over since I first built this car. With this Omnimic setup it should be easy to double check that I'm not downgrading.
> 
> Look at it this way guys, more tests comming up!
> 
> I just called Vin to pick up my Omnimic and sealed box sub. I want to test the AE and the SLS a lot before they get replaced. Should be fun!


I understand entirely. I'm in the exact same boat. The testing has given me am allergic reaction. 

Don't be surprised if my entire system goes up for sale here soon. Lol.


----------



## BowDown

Note to self: Never test any of the drivers in my system.


----------



## cvjoint

Remember when we were talking about reasons to cross a midbass low, say 63hz compared to 100hz? One of my points was that with a subwoofer crossed high, at 100hz you get this null somewhere around 70hz whereas when a midbass covers the same region there isn't one. I promised I would try to get some evidence. I was in the car last night trying to get the last tests done on the AE subs and the SLS midbass drivers before they get replaced. 

Here is the unsmoothed frequency response of both the sub and the midbass overlapped to have roughly the same output between 50hz and 100hz. 










There is a 10db nose dive in the frequency response of the subwoofer, here in red, and no dip in the midbass response over the same region. There is something about the car environment where a rear mounted woofer excites this rear mode yet a door mounted woofer does not.

Another cool test would be to run the midbasses together to see if there are nulls forming when they work at the same time. 

These will be clear again in the fundamental plots in the HD graphs but I'll have to wait on those until I get the replacement subs and midbasses in. 

I therefore stand by my statement that low crossed door midbass drivers are immune to the midbass null in a way that rear mounted subwoofers are not.


----------



## Brian Steele

cvjoint said:


> There is something about the car environment where a rear mounted woofer excites this rear mode yet a door mounted woofer does not.


Agreed.




cvjoint said:


> I therefore stand by my statement that low crossed door midbass drivers are immune to the midbass null in a way that rear mounted subwoofers are not.


Agreed.

However, I think it's a bit much to ask a door-mounted midbass driver to do anything serious below 100 Hz at car audio levels, particularly as it's usually mounted infinite-baffle in what basically constitutes a horrible enclosure by any definition. The resulting distortion is more audible and annoying to me than a brief dip at around 70 Hz or so.

BTW - I was experimenting with using a "loading" shelf above my trunk-mounted subs (they're mounted in the spare tire well). I liked how the result sounded - that troublesome transition point between subs and midbass sounded audibly tighter, so I'm going to try and quantify the difference with an RTA meter this weekend and perhaps make it a permanent part of my install. Maybe it dealt with the notch, or maybe it made it much narrow, reducing its audible effect.


----------



## subwoofery

Brian Steele said:


> Agreed.
> 
> 
> 
> 
> Agreed.
> 
> However, I think it's a bit much to ask a door-mounted midbass driver to do anything serious below 100 Hz at car audio levels, particularly as it's usually mounted infinite-baffle in what basically constitutes a horrible enclosure by any definition. The resulting distortion is more audible and annoying to me than a brief dip at around 70 Hz or so.
> 
> BTW - I was experimenting with using a "loading" shelf above my trunk-mounted subs (they're mounted in the spare tire well). I liked how the result sounded - that troublesome transition point between subs and midbass sounded audibly tighter, so I'm going to try and quantify the difference with an RTA meter this weekend and perhaps make it a permanent part of my install. Maybe it dealt with the notch, or maybe it made it much narrow, reducing its audible effect.


Can't wait to see your results... 

Kelvin


----------



## cvjoint

Brian Steele said:


> Agreed.
> 
> 
> 
> 
> Agreed.
> 
> However, I think it's a bit much to ask a door-mounted midbass driver to do anything serious below 100 Hz at car audio levels, particularly as it's usually mounted infinite-baffle in what basically constitutes a horrible enclosure by any definition. The resulting distortion is more audible and annoying to me than a brief dip at around 70 Hz or so.
> 
> BTW - I was experimenting with using a "loading" shelf above my trunk-mounted subs (they're mounted in the spare tire well). I liked how the result sounded - that troublesome transition point between subs and midbass sounded audibly tighter, so I'm going to try and quantify the difference with an RTA meter this weekend and perhaps make it a permanent part of my install. Maybe it dealt with the notch, or maybe it made it much narrow, reducing its audible effect.


Yep, totally agree. That's why I've been using 10" in my previous car. In this car I used those B&Cs only over 100hz. I suspect the vast majority of 7s are inadequate for crossing bellow 100hz, especially since the B&Cs are some of the higher output drivers out there. 

But..., the SLS has shown I hope that *some* 7"s can bring it. I previously posted a test of the SLS at 115db 63hz up to 200hz. It had under 1% distortion everywhere and that's in a door. So the total distortion of the driver plus door installation should be under audible levels. Now there are two of them, so that makes it 121db of "distortion free" output. Given the 10db dip, the sub assembly would have to put out 130db of similar low distortion output at 65hz just to keep up with a pair of SLSs in door. The SLSs are very attractive and I'd venture to say capable to be crossed down to 63hz. 

Looking forward to your results. Personally I don't know why the null occurs so I wouldn't know how to fix it without moving a capable driver up front.


----------



## 60ndown

some of you are crazy, we all know a diver changes its tonality with air temperature, age (break-in) and volume (and maybe a few others) ?

the differences in performance you guys are worrying about are so small, and they will likely change after the driver has been used for a couple of months (all new drivers do)

you have to use/listen to a driver for a while and keep tuning it to have a real world idea of what its actually going to sound like.

testing is one thing, human hearing is another.

are you addicted to shopping for new speakers/electronics? 

can you even enjoy listening to music any more?

havent there been some AMAZING iacsa sq winning systems over the years built with very modest equipment and good ideas and implementation?

all car audio problems are not fixed by buying and using 'perfect' drivers.


----------



## 24th-Alchemist

Sorry, I'm having trouble keeping pace with the thread (busy). I just wanted to wrap up one last detail even though it's old.



> Am I right in saying that you believe higher bandwidth speaker have quicker decay not only when tested with an impulse response but in reality as well? I can see how the bandwidth can affect CSDs now, but not really sure bandwidth affects decay in itself.


I think we need to be careful about what exactly we mean by "decay". On page 12 of this thread I defined "decay" for an impulse response in the time domain as the reduction in the square of the area under the response curve. The plots on p12 show that a short time after the response onset, the wider bandwidth driver has less total area under the square of the remainder of its response than the narrow band driver, i.e. quicker decay. (And this is in spite of the fact that the wide band driver dissipates more total energy). We can also see this quicker decay in the CSDs in the frequency domain. That said though, the degree to which the decay is quicker is qualitatively subtle IMO.

Since an impulse response provides a complete characterization of a linear system, it's hard to know what is meant by "real-world". If real-word means considering non-linearities, then I suppose one possibility might be to try and draw inferences from the CSDs as best as possible. On the other hand, if "real-world" is referring to responses to more typically encountered signals such as those in music, then I think some of the plots I posted previously demonstrate that a wider bandwidth driver "decays" more quickly in the sense that it follows a music signal more closely than a narrower band driver -- i.e. a wider-band (e.g. low _Le_) driver does indeed provide "faster bass" -- except for two real-world caveats: (1) if there is phase distortion (as there is in some of the plots I posted previously), it may be difficult to see how a wider band driver is doing a good job of "following" or "keeping pace" with a music signal, but more importantly (2) if a music signal is low-passed, it is then inherently "slow", so it is often not necessary to have a "fast" wide-band driver because the signal is too slow to necessitate a great deal of speed. Caveat two is illustrated in the last two plots I posted on this thread (p14). The differences between "fast" (wider bandwidth) and "slow" (narrower bandwidth) drivers -- where, importantly, both drivers are playing "music-like" signals within their passbands -- can be seen by comparing the blue and green traces in the plots. Recall that I listened to the simulated signals for both cases on two different sets of headphones and several different DACs, and the differences between wide- and narrow-band drivers both playing signals within their passbands were inaudible for me -- getting back to my opinion that the differences in decay are "subtle", with the important qualifier that this "subtlety" applies when both drivers are playing signals within their passband. (See the first plot I posted on p14 for a comparison of drivers playing signals that are not within their passbands).


----------



## cvjoint

24th-Alchemist said:


> Sorry, I'm having trouble keeping pace with the thread (busy). I just wanted to wrap up one last detail even though it's old.
> 
> 
> 
> I think we need to be careful about what exactly we mean by "decay". On page 12 of this thread I defined "decay" for an impulse response in the time domain as the reduction in the square of the area under the response curve. The plots on p12 show that a short time after the response onset, the wider bandwidth driver has less total area under the square of the remainder of its response than the narrow band driver, i.e. quicker decay. (And this is in spite of the fact that the wide band driver dissipates more total energy). We can also see this quicker decay in the CSDs in the frequency domain. That said though, the degree to which the decay is quicker is qualitatively subtle IMO.
> 
> Since an impulse response provides a complete characterization of a linear system, it's hard to know what is meant by "real-world". If real-word means considering non-linearities, then I suppose one possibility might be to try and draw inferences from the CSDs as best as possible. On the other hand, if "real-world" is referring to responses to more typically encountered signals such as those in music, then I think some of the plots I posted previously demonstrate that a wider bandwidth driver "decays" more quickly in the sense that it follows a music signal more closely than a narrower band driver -- i.e. a wider-band (e.g. low _Le_) driver does indeed provide "faster bass" -- except for two real-world caveats: (1) if there is phase distortion (as there is in some of the plots I posted previously), it may be difficult to see how a wider band driver is doing a good job of "following" or "keeping pace" with a music signal, but more importantly (2) if a music signal is low-passed, it is then inherently "slow", so it is often not necessary to have a "fast" wide-band driver because the signal is too slow to necessitate a great deal of speed. Caveat two is illustrated in the last two plots I posted on this thread (p14). The differences between "fast" (wider bandwidth) and "slow" (narrower bandwidth) drivers -- where, importantly, both drivers are playing "music-like" signals within their passbands -- can be seen by comparing the blue and green traces in the plots. Recall that I listened to the simulated signals for both cases on two different sets of headphones and several different DACs, and the differences between wide- and narrow-band drivers both playing signals within their passbands were inaudible for me -- getting back to my opinion that the differences in decay are "subtle", with the important qualifier that this "subtlety" applies when both drivers are playing signals within their passband. (See the first plot I posted on p14 for a comparison of drivers playing signals that are not within their passbands).


I'm sold.  My hesitation was simply due to a lack of mechanism by which a wider bandwidth translates to lower decay. The simulations you posted combined with Andy's post on how the coil and soft parts store energy come together really nicely. 

I'd be down for more simulations and such on the implications of non-linearities for CSDs. That's of course, whenever your time permits. Most of the heavyweights like Zaph use CSDs simply to pick up "ribs" and therefore signs of resonance which I assume is what you mean by non-linearities.


----------



## SSSnake

> I therefore stand by my statement that low crossed door midbass drivers are immune to the midbass null in a way that rear mounted subwoofers are not.


CV,

While I agree that this is a pretty typical occurrence, I can assure you that it is not always true. Therefore, statements like "immune" make me very nervous. 

I have been struggling with a null on my midbasses at 80Hz, peak at 160, null at 320... Classical contructive destructive interference pattern. I finally broke down and crossed the sub over at 100hz lp and the mids at 100 hp. The null that you show in your measurement is absolutely not there in my system (as a matter of fact I need a little cut in that range). So while I do believe your measurements indicate a typical interference pattern I don't belive it is the only interference pattern. The lesson is listen, measure, and use the tools at your disposal appropriately. In my case keep the null out of the 80hz passband of the mid and let the sub pick it up.

However, the kicks will be rebuilt to try and break up the interference pattern because I still have a null at 320hz (less offensive but still there). 

BTW - I will see if I saved the measurements on my other computer. If not they are pretty easy to replicate.


----------



## cvjoint

SSSnake said:


> CV,
> 
> While I agree that this is a pretty typical occurrence, I can assure you that it is not always true. Therefore, statements like "immune" make me very nervous.
> 
> I have been struggling with a null on my midbasses at 80Hz, peak at 160, null at 320... Classical contructive destructive interference pattern. I finally broke down and crossed the sub over at 100hz lp and the mids at 100 hp. The null that you show in your measurement is absolutely not there in my system (as a matter of fact I need a little cut in that range). So while I do believe your measurements indicate a typical interference pattern I don't belive it is the only interference pattern. The lesson is listen, measure, and use the tools at your disposal appropriately. In my case keep the null out of the 80hz passband of the mid and let the sub pick it up.
> 
> However, the kicks will be rebuilt to try and break up the interference pattern because I still have a null at 320hz (less offensive but still there).
> 
> BTW - I will see if I saved the measurements on my other computer. If not they are pretty easy to replicate.



Yeah, that was a bad conclusion on my part. The lessons learned from my tests do not apply universally. Got a little carried away. 

Maybe I can move this to the next level with a quote from Geddes:

_This landscape is different for every position in the room and for every position of the sub and its entirely different for every room. One cannot approach a problem like this as if there is a singular solution, a one size fits all so to speak. To make a long story short, we must look to statistics to solve this problem. We must look for ways that will reduce the variability of the peaks and dips in both the frequency response as well as the response around the room. The reason for this is that if the response is different at every point then EQing the sound at one point will only make it worse at another point – there is no EQ that can correct the situation except for a single point. On the other hand if we could reduce the variability of this response from point to point then we could apply some EQ and correct the entire problem. Statistically this comes about by using averages – by using multiple LF sources that will average out to a smoother spatial variation which can then be EQ’d for a total global solution. One can obsess about the best locations and number of sources, and papers have been written on this subject, but it all comes down to a simple approach. Use multiple subs placed at fairly random locations in the room – in other words place them wherever you want, just so long as they are not close to one another. It has been shown that this will smooth out the spatial variation of these sources thus allowing for a global EQ’d solution._

The entire manuscript is available here:
http://www.gedlee.com/downloads/Philosophy.pdf

Basically use as many subs as possible and mount them far away from each other as you can. I would say this is a point for adding more dedicated midbass drivers. Two midbass drivers in opposite doors do a better job at averaging to a smoother FR than one sub. This plays in nicely with Lycan's arc too.  It could work for subs as well but subs are too large to be thrown all over the car. By default the midbass drivers have two locations not near eachother and it's much easier to get an additional pair of 7"s than 12"s. 

This gives me crazy thoughts of adding another pair of SLS somewhere lol


----------



## ErinH

Many folks employ this for home audio use. It's on my list (IB up front and satellite subs around to smooth the response). 

Jeff highly suggested this method and a few of us have discussed it on MSS. Adam seems to be really gunning for it and I've been experimenting with a 12" PR in the dash to see what it does. 

All in all, it's a very worthwhile approach. My issue is if you already use a 3-way+sub, you're using some channels already. Good thing for eight channel processors.


----------



## cvjoint

I guess in car audio it only matters if you care about the passenger. The response for the driver is already equalized for the driver and that's really all I care about haha. In HT you're going to be sitting in different positions on the couch depending on who's sitting where, makes more sense there. 

12" PR in the dash you say? Maybe I'll take a look.


----------



## ErinH

Well, it's not just about the passenger. 
Smoothing the overall response via distanced mid basses helps alleviate issues caused by reflections, like Charles discussed above. Some cars are less troublesome than others. Mine is a beeotch at 70hz. 

I don't have pics of the PR. I will no longer be updating my build log. Call me jaded. Lol.


----------



## cvjoint

bikinpunk said:


> Well, it's not just about the passenger.
> Smoothing the overall response via distanced mid basses helps alleviate issues caused by reflections, like Charles discussed above. Some cars are less troublesome than others. Mine is a beeotch at 70hz.
> 
> I don't have pics of the PR. I will no longer be updating my build log. Call me jaded. Lol.


I already looked at your build thread, sheesh. I think you owe us at least a pic. 

Erin, did you see this before:

Critical Mass UL12 Subwoofer Review - Subwoofer Reviews - Car Audio and Electronics

I thought this was all hype but it tests incredibly well.


----------



## thehatedguy

They are going for about $2200 each on ebay too.


----------



## ErinH

thehatedguy said:


> They are going for about $2200 each on ebay too.


Goooood Looooorrrrd.


----------



## thehatedguy

Search for them...I about fell out of my chair laughing.


----------



## thehatedguy

My bad....they are about 3 grand each.

Other Sizes | eBay


----------



## cvjoint

Yeah, the pricing is a joke but otherwise it's a top performer. Interestingly enough it models rather poorly. Just like the Eclipse LMS it needs true infinite baffle and even then the Q is too high. No wonder the TS parameters are so hard to find, it ruins the image of "best subwoofer." Because it was born in the decade of SPL circuits it probably trades off good group delay performance for all out SPL and power soaking. 

It looks like a Cervin Wega stroker on a diet. Same performance but much lighter and freer flowing. Whoever built this thing should try again with better TS params and lower price point. Some of the money can be saved by using a plain aluminum cone and a flat finish on the basket. I would pay near $500 for a new unit with these changes. Three times the stroke of the XXLS for three times the money, fair enough.


----------



## subwoofery

cvjoint said:


> Yeah, the pricing is a joke but otherwise it's a top performer. Interestingly enough it models rather poorly. Just like the Eclipse LMS it needs true infinite baffle and even then the Q is too high. No wonder the TS parameters are so hard to find, it ruins the image of "best subwoofer." Because it was born in the decade of SPL circuits it probably trades off good group delay performance for all out SPL and power soaking.
> 
> It looks like a Cervin Wega stroker on a diet. Same performance but much lighter and freer flowing. Whoever built this thing should try again with better TS params and lower price point. Some of the money can be saved by using a plain aluminum cone and a flat finish on the basket. I would pay near $500 for a new unit with these changes. Three times the stroke of the XXLS for three times the money, fair enough.


For those that want to model it too: 
http://web.archive.org/web/20060616074806/http://criticalmassaudio.com/pressRelease/UL12/CAEP-060700-CRITICAL.pdf 

Kelvin


----------



## cvjoint

subwoofery said:


> For those that want to model it too:
> http://web.archive.org/web/20060616074806/http://criticalmassaudio.com/pressRelease/UL12/CAEP-060700-CRITICAL.pdf
> 
> Kelvin


Wow, that models even worse than if you use CM manufacturer data. The subwoofer itself does save weight if you compute output at xmax compared to other subs. The trick is you need two alternators, a couple enormous amplifiers chained together, and 12'x12' infinite baffle to mount it on. :laugh:


----------



## subwoofery

Bandpass maybe? 

Kelvin


----------



## Cenovio

Yea, a pic would be nice.


----------



## thehatedguy

I wish werewolf was still around, he and the CEO of CM went back and forth on another forum about that sub.


----------



## cvjoint

thehatedguy said:


> I wish werewolf was still around, he and the CEO of CM went back and forth on another forum about that sub.


Link?


----------



## cvjoint

I was toying with the idea of running Logic 7 in this car and how it would work out. It's actually quite doable. The shopping list would be the following:

1. MS8 connected to phone via rca to minijack cable. This will still allow be to have voice guided GPS and make phonecalls using the phone's mic and car's spekaers. The smartphones also have radio. I would only be missing a CD transport. 

2. 5x Vibe Litebox 4's. That would give me 20 channels of up to 2500 watts. 

3. BG Neo10 + AMT tweeter for left, center, right. The crossover would be done via a simple inline filter on the AMT tweeter, probably at 12khz or so. The planar would be running 200hz up. 150w each for the planars, 75w for the AMT supertweeters. 

4. SLS 6.5"s in the doors 63hz-200hz. 250w each

5. Rear speakers would be driven by MS8 built in amp, the Faital 4" would run 100hz-20,000hz. It's the only speaker I know that's loud enough to do it and wideband enough. Maybe 12w each. 

6. Three 12" subs, 250w each.



The problem I see with the MS8 setup is that there will be a DA conversion in the smartphone. Then there will be a AD conversion in the MS8, then again a DA conversion to go the amps. On top of this there will be some inline filters for the supertweeters so it's not all active. 

On the bright side with Logic 7 maybe the car will sound a lot bigger than it is. Time alignment will be taken care off by splitting the fronts into 2way, midbass plus planar/AMT. The planar/AMT in the left center right would be close enough to align the same. 

There will be no headunit so the MS8 weight will be a wash. The center and rear speakers would weigh about 10lbs extra. The amps will weigh the same. I won't have to pull long RCAs to the front of the car so the weight gains would be 8lbs at most, quite negligible. 

Something to chew on for the future.


----------



## t3sn4f2

cvjoint said:


> I was toying with the idea of running Logic 7 in this car and how it would work out. It's actually quite doable. The shopping list would be the following:
> 
> 1. MS8 connected to phone via rca to minijack cable. This will still allow be to have voice guided GPS and make phonecalls using the phone's mic and car's spekaers. The smartphones also have radio. I would only be missing a CD transport.
> 
> 2. 5x Vibe Litebox 4's. That would give me 20 channels of up to 2500 watts.
> 
> 3. BG Neo10 + AMT tweeter for left, center, right. The crossover would be done via a simple inline filter on the AMT tweeter, probably at 12khz or so. The planar would be running 200hz up. 150w each for the planars, 75w for the AMT supertweeters.
> 
> 4. SLS 6.5"s in the doors 63hz-200hz. 250w each
> 
> 5. Rear speakers would be driven by MS8 built in amp, the Faital 4" would run 100hz-20,000hz. It's the only speaker I know that's loud enough to do it and wideband enough. Maybe 12w each.
> 
> 6. Three 12" subs, 250w each.
> 
> 
> 
> The problem I see with the MS8 setup is that there will be a DA conversion in the smartphone. Then there will be a AD conversion in the MS8, then again a DA conversion to go the amps. On top of this there will be some inline filters for the supertweeters so it's not all active.
> 
> On the bright side with Logic 7 maybe the car will sound a lot bigger than it is. Time alignment will be taken care off by splitting the fronts into 2way, midbass plus planar/AMT. The planar/AMT in the left center right would be close enough to align the same.
> 
> There will be no headunit so the MS8 weight will be a wash. The center and rear speakers would weigh about 10lbs extra. The amps will weigh the same. I won't have to pull long RCAs to the front of the car so the weight gains would be 8lbs at most, quite negligible.
> 
> Something to chew on for the future.


Droid X Symbiosis?

Have you checked to see if that phone can have a digital output some how? Through a special dock, USB "on the go", HDMI, etc.

I'm sure you know but all you'd need then is the DAC. Which if you go this route will allow you to pick the DAC instead of having to gamble with the phone's analog output > MS-8 analog input combination. 

The results would then be audibly identical to a digital output into a processor with digital inputs. Or better even, depending on how well that processor's digital input handles the jitter profile of the smart phone's digital output. 

And judging from Erin's Beach Audio sound card into the Bitone's digital in IMD measurements, it can be a big measurable difference. WAYYY more degrading that an affordable quality D to A > A to D process.

*Beach Audio digital out > H800, H701, Bitone digital in: * 

(Photos courtesy of Bikinpunk's review forum)











*Alpine W505 digital out > H800 digital in:*

Note the change just from using a different digital source, particularly in IMD. (Again, this is a change in measurements and would likely not affect the sound. The purpose here is to show that a D to D interface isn't _always_ "better" than a D to A > A to D interface.) 











*E-MU 0404PCI D to A > A to D*
(The quality affordable interface I was referring to above)

Results are the one in the first column.











*iPhone 3GS headphone output > E-MU analog input":*
(And the infamously "crappy"  iPod output for good measure)

Results are in Column "A"


----------



## thehatedguy

If you are going that route, I would put the rears on the Litebox amps too. You don't want the limiting factor to be the internal power of the MS-8.


----------



## cvjoint

t3sn4f2 said:


> Droid X Symbiosis?
> 
> Have you checked to see if that phone can have a digital output some how? Through a special dock, USB "on the go", HDMI, etc.
> 
> I'm sure you know but all you'd need then is the DAC. Which if you go this route will allow you to pick the DAC instead of having to gamble with the phone's analog output > MS-8 analog input combination.
> 
> The results would then be audibly identical to a digital output into a processor with digital inputs. Or better even, depending on how well that processor's digital input handles the jitter profile of the smart phone's digital output.
> 
> And judging from Erin's Beach Audio sound card into the Bitone's digital in IMD measurements, it can be a big measurable difference. WAYYY more degrading that an affordable quality D to A > A to D process.
> 
> *Beach Audio digital out > H800, H701, Bitone digital in: *
> 
> (Photos courtesy of Bikinpunk's review forum)
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> *Alpine W505 digital out > H800 digital in:*
> 
> Note the change just from using a different digital source, particularly in IMD. (Again, this is a change in measurements and would likely not affect the sound. The purpose here is to show that a D to D interface isn't _always_ "better" than a D to A > A to D interface.)
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> *E-MU 0404PCI D to A > A to D*
> (The quality affordable interface I was referring to above)
> 
> Results are the one in the first column.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> *iPhone 3GS headphone output > E-MU analog input":*
> (And the infamously "crappy"  iPod output for good measure)
> 
> Results are in Column "A"


So what you are saying is that we really don't know which conversion is better, it depends on the quality of the conversion. That kinda blows, because unless we have good tests it's a trial and error with a by ear test. 

*Option 1, use minijack* One thing I can do is test the minijack out quality right now with the p99/droid x combo. I can do a bluetooth vs. usb vs. cd. vs. minijack comparison. The conversions would be D-D plus D to A, D to A, D to A, A-D and D to A in that order. This option would also suffer from pops when plugging the rca in. I'm guessing MS8 or H800 has input sensing to know when to turn on? 

*Option 2. HDMI to optical* Like you said I could get a digital signal out of the Droid X. I can do mini hdmi to optical conversion. That requires a hdmi to optical converter that has to be powered. Depending on the converter quality it could sound good or not. The Droid X would also have to channel the audio signal through HDMI cleanly. 

*Option 3. BT to optical* Then there are bluetooth to optical converters. Not sure again how good the D to D conversion is for these. Results would vary I would think. 

*Option 4. USB Host to optical* This will be available in version 3.1 Android. I can wait till the Droid Prime comes out with USB hosting. That way I can power my phone on the USB and output optical from it. Is that even possible, power in and signal out from the same usb?

The Ms8 does not have digital input right? We also don't have any tests of its analog output? 

I suppose I would need another 2 channel Vibe sigh.


----------



## t3sn4f2

1- Andy mentioned that the MS-8 only puts out the voltage you put in, so that phone might only leave you with sub 1 volt RMS to the amps. Although, the MS-8 does have an AUX (-) - (center) - (+) volume slider on the tone menus, so I don't know how it would handle the AUX in then. Those phone will probably have something in the range of .5 volts only also. iPhone/iPods are around .9 volts. You could slap on a JL HD-RLC in the dash. That'll bump up the voltage some and make the signal better suited for a cable run through the cabin, as well as giving you a handy knob for MVC. If you can live without the MVC option then maybe a Zapco symbi driver will be a better option. The MS-8 has diff bal. inputs so you would not need to converter back to unbalanced on the receiving end of the symbi.

2- In this option, you should also conceder the total cost. The converter will be anywhere from $120-$350. The DAC, you can imagine but lets start it at $200 for one with a strong output and balanced outs. An ASRC module from minidsp to clean up any jitter issues between the unknown smart phone to Toslink output + DAC combo (it goes between the hdmi converter and the DAC. And needs to be powered also). The power supply or supplies for everything. Any other miscellaneous hardware. Maybe a custom multi output trigger circuit to turn on the digital device in an order that allows for proper syncing (assuming that becomes an issue after all pieces are integrated. possible but not likely).

And how much can you get for the P99 and how much will you loose on the sale if you bought it new? 

You might be better of just keeping the P99 and using it as a high end preamp/transport/USB/blue tooth variable output source. Along with all other things that come from a hardware piece that is designed around a mobile environment (ie volume dependant loudness contour, steering remote, tuner, etc.).

3- Never looked in to those.

4- Another good option. Probably not as solid as HDMI since it doesn't have to go through all the licensing and certifications that HDMI does (I think). Doubt you can charge at the same time since the DAC will be expecting power from the phone or from an external source.


----------



## cvjoint

^^ Great info, there is lots to think about. None of the options look easy. Maybe I'll get lucky and Verizon will release an optical out Android phone. :blush:

Got some raw goods to make subwoofer grilles out of: 



















The grilles that are out there for car subwoofers are either too boring, like the PE ones, too heavy and resonant, like the PE ones or too gaudy looking like most of the car audio stuff. 

I'm just going to cut the strip in two and use the screws that mount the sub to hold the strips over the sub at the same time. I'll use some aluminum spacers to elevate the strips over the surround.


----------



## SSSnake

> If you are going that route, I would put the rears on the Litebox amps too. You don't want the limiting factor to be the internal power of the MS-8


VERY GOOD advice!


----------



## cvjoint

New subwoofers are in!!! These are the sexiest speakers I have ever laid eyes on. The second sexiest speaker might as well be the last the difference is so huge. 

Now I just have to figure out a way to showcase their light weight. I can lift all three on a pinky I just can't figure out a way to grasp them since they are full size 12s. 

Pictures coming in a few minutes, phone is charging!


----------



## fish

cvjoint said:


> New subwoofers are in!!! These are the sexiest speakers I have ever laid eyes on. The second sexiest speaker might as well be the last the difference is so huge.
> 
> Now I just have to figure out a way to showcase their light weight. I can lift all three on a pinky I just can't figure out a way to grasp them since they are full size 12s.
> 
> Pictures coming in a few minutes, phone is charging!



Did you end up going with these George?

Vifa NE315W-04 12" Neodymium Woofer 264-1120


----------



## cvjoint

fish said:


> Did you end up going with these George?
> 
> Vifa NE315W-04 12" Neodymium Woofer 264-1120


Yep, the Vifa NE 315W-04 is the new addition to the family. 

First off the pictures:
































































*Build quality impressions* based on the glove work:

The basket is built around the neo motor. I'm guessing by design the magnet can't shift due to the way the aluminum spokes grab onto it. Faital keeps mentioning this about their speakers so I do too haha. The spokes are rounded off inside and outside, incredibly well vented is the way to describe them. The benefit of the small neo motor is actually bellow the spider where again it's incredibly well vented. The lip has no felt treatment but it has a very subtle edge pronunciation. Perhaps it digs into whatever surface it's mounted on to make an even more airtight seal. The screw holes are countersunk, in a driver with this much high frequency extension I bet it helps. Whoever designed this basket really loved his job, you can see they even took the time to countersink the logo into the basket. 

The voice coil former is titanium and it has loads of thermal relief vents. Titanium is used presumably to prevent the coil from unwinding under extreme temperatures. It happens to have very good magnetic properties. In case the former vents don't due the job of unloading the dustcap cavity the magnet has a pole vent to help it out. 

The spider is moderately sized, fairly see through, and fairly stiff. The voice coil leads seem to be soaked and stitched from the back of the spider. They terminate into a screw type block with allen type screws, pure sex. 

The cone is some sort of paper pulp. Very smooth on the outside but very rough on the inside. The surround is a bit beefier than it looks in the pics. I can't tell whether the protective rubber right around it is the same piece. At the basket spoke location the surround extends out. Interestingly enough the back of the cone terminates abruptly in these places and the surround takes over. Not sure what this pentacone technology is supposed to do, maybe reduce standing waves. The small dustcap is unusual but makes for very radical concavity. From the side these cones look really really good just like a concave car wheel looks way sexier than than a flat surface one. 3d vs. 2d.

Next I'll put everything at my disposal in service to do a full on comparison between the outgoing AE IB12 and the new Vifas. For now the weight difference is astounding. 1 AEIB12 is 15lbs, whereas 3 Vifas are 18lbs. The Vifas are hella curvaceous by comparison too. Just how I walk past my car somedays and just drool at the body lines I will drool at these Vifas in ways I've never drooled at speakers.


----------



## fish

6 pounds!  Just crazy! 

Now the big question...

With 9mm of Xmax do you think they'll have the output you're accustomed to?


----------



## cvjoint

fish said:


> 6 pounds!  Just crazy!
> 
> Now the big question...
> 
> With 9mm of Xmax do you think they'll have the output you're accustomed to?


Exactly why I didn't buy these the moment they came out. 9mm of claimed stroke and 150w power handling. You would think hey, this looks like a midrange. Indeed, this is one of the finest 12" midranges that were ever made, I have this frequency response plot from V.C. magaz that goes up to 6khz almost flat. However in the same magazine there is the Klippel test, and it looks fantastic. As in the 12m, HAT L4, Faital comparison thread I will start with the Klippel comparison, add TS parameters, and close with a bunch of simulations. Unlike the 4.5" comparison I do have both the AE and the Vifa on the Omnimic so I'll show you guys in car plots of nonlinear distortion and frequency response to boot. 

*Klippel Comparison*
*AE IB12A*

X Bl @ Bl min=70% >12.5 mm 
X C @ C min=50% *10.8 mm *
X L @ Z max=20% >12.5 mm 

The AE absolutely dominates in the motor department. It seems to have about 18mm or so of linear motor stroke. The inductance is also extremely low for a 12" driver and extremely linear. The voicecoil, while similar in size to the Vifa is heatsinked by the shorting sleeve with great results. However, the tight pro audio suspension while light, practical and low resonance induces nonlinearities in CMS very early on, resulting in an Xmax of 10.8mm. You can see that in this test Matt couldn't actually push the suspension enough to even resolve the motor .7 Bl point. 


*Vifa NE 315*

X Bl @ Bl min=70% =*11.9 mm *
X C @ C min=50% 17.9 mm 
X L @ Z max=?

The Vifa is the opposite of the AE. Here we see an impecable suspension construction. The rather small, but still larger than the AE, surround coupled with a midsized spider seem to give this driver gargantuan linearity. Combine that with the free flowing basket and the unobstructive neo motor and you have a world class suspension. Small enough not to eat into cone area yet linear enough to handle even the most brutish motors. The motor is not as strong as the AE, mostly probably due to the cost of having a larger Neo, and maybe partly because Peerless is not interested in very large displacement speakers. With 11.9mm of motor stroke this Vifa comes in at a nice 11.9mm Xmax motor limited, 1.1mm more than the AE. The inductance limits are not listed in the review, but the inductance is curved on the positive displacement side and overall it is fairly low. Not great, but definitely good enough for subwoofer to midrange use. 

The Vifa then has the higher Xmax but overall I expect both to have similar large signal performance. The suspension on the AE is about as limiting as the motor on the Vifa, and they both have great everything else. The Vifa NE is more like an XXLS than I thought. Its large signal performance is on par yet manages to have better efficiency, TS parameters, and a more extended response. This is the new and improved XXLS, people just don't know it yet.


----------



## ErinH

That 6 lbs is enticing for sure. 

What issue was the vifa tested in?


----------



## subwoofery

bikinpunk said:


> That 6 lbs is enticing for sure.
> 
> What issue was the vifa tested in?


The NE315W-04 was tested in the July 2010 issue 

Kelvin


----------



## ErinH

Hmmm.... they look pretty interesting. I just pulled up the issue of VC and am pretty damn impressed. Moreso, I'm floored by the weight. That's just insane. 
The price difference between Madisound and PE is CRAZY, though... over $200 difference for ONE driver. 

George, I'll be waiting on your simulations. I may jump on this ship with you and store them for a future build before Neo prices hit PE.


Side note: I wonder why Matt couldn't get Bl to resolve for the IB12...


----------



## cvjoint

bikinpunk said:


> Hmmm.... they look pretty interesting. I just pulled up the issue of VC and am pretty damn impressed. Moreso, I'm floored by the weight. That's just insane.
> The price difference between Madisound and PE is CRAZY, though... over $200 difference for ONE driver.
> 
> George, I'll be waiting on your simulations. I may jump on this ship with you and store them for a future build before Neo prices hit PE.
> 
> 
> Side note: I wonder why Matt couldn't get Bl to resolve for the IB12...


This is one of the best buys ever. I encourage everyone to jump on these, I just get flabbergasted everytime I look, hear, weigh, or think about how much of a steal they were at those PE prices. Don't forget to use the PE coupon...for each. 

I got them in the car just 2 hours ago. They sound fantastic, just like the AE to my ears. The difference is that the bottom end is more pronounced but the top end is more subdued. The transfer function is going to be a bit flatter for these guys. That seems to help with localization issues too. I should have used a steeper slope on the AEs to make them sound more like these guys. 

Anywho I probably pumped over 700w into them and they seem fine. The Clarion xh7100 also seems to handle the 1 ohm load rather well, just like the guy from Nicola Engineering said it would. I'm a happy camper.



The Klippel could not get all of the BL because I'm guessing the suspension is too tight by comparison. The AE has an xmech of 22mm, and a rated BL xmax of 18.5mm. That's only 3.5mm before boom boom pow. Similar story with the Illuminators, all motor dominated designs, except you went all out near xmech to resolve it.


----------



## Brian Steele

cvjoint said:


> This is one of the best buys ever. I encourage everyone to jump on these, I just get flabbergasted everytime I look, hear, weigh, or think about how much of a steal they were at those PE prices. Don't forget to use the PE coupon...for each.


Those do look very, VERY good at that price. Looks like a decent match for a simple 1 cu.ft. sealed box too. The low power rating does worry me a little though.


----------



## cvjoint

The Peerless SLS is rated at 50w, and I can vouch I pumped over 200w into them for a prolonged period of time. These are rated three times over by the same company. You can wait to see if I burn mine down but you risk missing the great pricing. 

If pricing is really not a variable for you they will eventually produce the 8 ohm version with a heatsink that bumps the rated output to 220w. I'm sure they'll do the same with the 4 ohm models. My guess is that's why PE is trying to clear them out. After that I expect them to be $240ish cheapest. Europeans are paying over 300e for these! 

The heatsink weighs a fraction of a pound so negligible weight increase. I emailed Vifa to ask if I can purchase the heatsinks separately. I'll update you all if I get a response.


----------



## t3sn4f2

How do these work IB with/in a typical sedan trunk? ~14cuft


----------



## Brian Steele

cvjoint said:


> The Peerless SLS is rated at 50w, and I can vouch I pumped over 200w into them for a prolonged period of time. These are rated three times over by the same company. You can wait to see if I burn mine down but you risk missing the great pricing.
> 
> If pricing is really not a variable for you they will eventually produce the 8 ohm version with a heatsink that bumps the rated output to 220w. I'm sure they'll do the same with the 4 ohm models. My guess is that's why PE is trying to clear them out. After that I expect them to be $240ish cheapest. Europeans are paying over 300e for these!
> 
> The heatsink weighs a fraction of a pound so negligible weight increase. I emailed Vifa to ask if I can purchase the heatsinks separately. I'll update you all if I get a response.


Ooh, I am SO tempted. I'm afraid that it isn't going to survive in the trunk of my car though. I'm interested in hearing what Vifa has to say about the heat sinks.


----------



## thehatedguy

I have it on record from a good friend of mine that the NE8s are beasts when placed in an enclosure.

I wish I could hook you guys up on the NE line, but the close out price is the same as wholesale...only retail gets free shipping over $100 and wholesale gets free shipping over $500.

Was the NE 6 tested by Vance? I don't remember if it was. I would be curious if they are more than Illuminator Jrs just on looks.


----------



## ErinH

I thought they were, and that's why I didn't bother to order the 6" version. But, apparently I mistook those for the 12" version George has ordered since I wasn't familiar with the model #. Doh!


I want to model these but the PC is upstairs and I don't feel like firing it up for the sake of that alone. I'm hoping someone here will do the dirty work and compare them to the AE's for me. Ahem... George..... 


Vance measured Qts between 0.22-0.27 for his different methods. That concerns me. I don't mind a 0.5 Q, but for a driver attached to only a baffle, that low of a Q is a bit scary. The suspension has good symmetry which makes me think it could probably hold it's own (ie: not crash, bang, boom) and the Fs is incredibly low being under 20hz, but still.... it's just the dang Qts that scares the piss out of me. 
Truth be told, I've got my ib15's attenuated so incredibly low that I absolutely know I don't need both of them; one 15 would probably suffice and 2 12's certainly would. 3 12's would keep distortion low but I don't believe I have the space for that.  


You know... here I was... all satisfied with my IB15's and George has to go post something up like these.


----------



## Brian Steele

thehatedguy said:


> I have it on record from a good friend of mine that the NE8s are beasts when placed in an enclosure.


Must.stop.fingers.inching.towards.credit.card...


----------



## Brian Steele

bikinpunk said:


> Vance measured Qts between 0.22-0.27 for his different methods.


What do you make of that high Qms? Kinda strange for a driver with what looks to be a rubber surround...


----------



## cvjoint

I still have to do all the uploading and stuff but here is the quicky. My car only has a 5 ft3 trunk. When you combine that with three 12s IB is more like a midsize box. They model to around .65 Qtc in my car. Some of you guys will have two to three times the trunk space and only a couple. That's gonna take the Qtc pretty low.

However, low Qtc is not that big of a deal. There are literally dozens of things to be more concerned about imo. You will basically get a bit more bottom end and they will be overdamped. More bottom end is a great thing to have, especially for a sub. The efficiency goes up too, less power needed for Xmax and therefore a given output.

My ideal Qtc (box plus speaker Qs) is .56 with the trunk empty. .56 is perfect group delay. That way with a few groceries it's still between .56 and .7. Going over .7 is what really sucks, group delay and the frequency response suffers. 

So too low of a Q is not the end of the world. Remember Q goes up when things go in the trunk as well, Q also goes up with excursion. It's better to start lower for realistic applications. It certainly wouldn't stop me from using these.

So that's the glass half empty type of response. Remember this speaker has very low resonance in parts, models great (high bandwidth 20hz-6khz), 12mm of verified Xmax, lightest true subwoofer, most gorgeous imo front or back, world class suspension, $114 shipped and the list goes on.


----------



## thehatedguy

2 in 12 cubes gets you a Q of .49 with an enclosure tuned at 31.3 hertz. Vifas are modeling about 3dB down from the AEs between 40-70 hertz.

3 of them in 12 cubes gets you a Q of .55ish.

Put you 1 ohm in series with a pair of the NE12s, and you raise the Q to .58 and get 3dB at 20hz gain compared to the AE15s. 250 watts would drive the pair to full excursion at 20 hertz that way.



bikinpunk said:


> I thought they were, and that's why I didn't bother to order the 6" version. But, apparently I mistook those for the 12" version George has ordered since I wasn't familiar with the model #. Doh!
> 
> 
> I want to model these but the PC is upstairs and I don't feel like firing it up for the sake of that alone. I'm hoping someone here will do the dirty work and compare them to the AE's for me. Ahem... George.....
> 
> 
> Vance measured Qts between 0.22-0.27 for his different methods. That concerns me. I don't mind a 0.5 Q, but for a driver attached to only a baffle, that low of a Q is a bit scary. The suspension has good symmetry which makes me think it could probably hold it's own (ie: not crash, bang, boom) and the Fs is incredibly low being under 20hz, but still.... it's just the dang Qts that scares the piss out of me.
> Truth be told, I've got my ib15's attenuated so incredibly low that I absolutely know I don't need both of them; one 15 would probably suffice and 2 12's certainly would. 3 12's would keep distortion low but I don't believe I have the space for that.
> 
> 
> You know... here I was... all satisfied with my IB15's and George has to go post something up like these.


----------



## ErinH

I'm not sure the hd750/1 can handle a 1 ohm load. So using 3 might be iffy. 

A pair would probably be it.
Though, if you go by Re you can get a final load of closer to 7 ohms. Still, not sure if the JL would like this. I'd have to check in to it.


----------



## cvjoint

*Klippel large signal results combined with tested TS parameters*

This first graph has a few restrictions, no speaker can exceed Xmax as tested, their continuous power ratings, and they have to be modeled in the same box (5ft3 - my trunk). This means that no speaker is over the 20% distortion limit, or breaking down from thermal stress. The one that can muster the most SPL with these conditions wins! 










When modeled with 450w on tap, max rating per Vifa, the NE ties with the AE in the bottom octave, but gets surpassed in the top octave. To do this, the AE needs 580w. The Vifa is power rating limited, excursion is only at 11.4mm whereas the AE is excursion limited at 10.8mm. If the true power ratings are really 150w on the Vifa and 500w for the AE the Vifa is power compression limited whereas the AE is excursion limited. Both get the same output and roughly the same distortion. *Result for distortion modeling: TIE
*
Here is a plot of excursion, box size, and Qtc:










You can see here the Qtc is .649 for Vifa, and .706 for the AE. *Results for best Qtc: winner-Vifa.* It requires a smaller box for the same Q, and in my tiny trunk smaller is better. Closer to .56 is better and the Vifa is closer. For some of you wanting to use them IB in a large trunk the AE might be a better choice if you want a decent Q. 

Realistically these coils inspire more confidence in me than 150w per. Here is what they both look like with 750w for the trio:










*The Vifa manages 1db more at 20hz if those coils hold up.* I also like the lower output up top, to me it doesn't pull the stage back as much. The flatter the response the better. In reality the Vifas get at most 850w from my amp since they are 4 ohm so I surely get more output down low if I really crank them. 

*Overall I'd say the Vifas model better but the power ratings can be a concern. *The heatsinked models would be a straight winner across the board. With 220w each you can easily exceed xmax in a box of .7 Q or lower and AEs thermal advantages don't play in anymore. I'll update you all if one does thermally fail. 

Even so the differences between these subs are rather minute. 
Both have nonaudible suspension noise to at least xmax from my in car experience with them. The subs are 2 feet from my ears, and there is nothing between me and them, so I would hear it. Both have very good decay qualities and can be used as a midbass or even midrange. 

*
Next I'll give the basic specification for sealed:*

1.343ft3 will give a .707 Qtc
150w in this box will driver it to only 10mm at 20hz, well bellow xmax
215w in this box will push it to xmax at 20hz


----------



## cvjoint

Pics of the Vifas on the same baffle as the AEs were. I added the home brew grilles this time. I cut the carbon fiber strips and drilled them. The screws hold both the grilles and the subs. It's an elegant, cheap, light and does the job kinda method, imo. 














































25lbs=3 subs, baffle, all wiring, screws, grilles. The other part of the IB that is in the car, the fiberglass that it bolts to, screws and sound deadening is about 10lbs. 

Lessons learned:

The carbon fiber strips should be thicker and wider. The strip cracks when drilling the screw holes. It should also be thicker for heavier subs as the screw might break it apart. The grilles also have to tightened well or the aluminum spacers start making their own noise. In fact plastic ones may be a better choice unless they collapse under load. I'll have to retighten the screws a few times in the next weeks while the subs settle.

Also don't use the screw terminals, they are way to tiny.


----------



## t3sn4f2

52 pounds? Good lord! :rolleyes2:


----------



## ErinH

hey... your subs overlap!


----------



## cvjoint

bikinpunk said:


> hey... your subs overlap!


Big things in tight places! The middle walls between the subs are only 1/4." If the Vifas were 320mm as opposed to 315mm they wouldn't work. 

If I don't overlap the trunk arms hit the baffle and the trunk won't close. That reminds me, I need to order some gas shocks to replace the trunk springs I removed to make the trunk IB.


----------



## t3sn4f2

bikinpunk said:


> hey... your subs overlap!


That was pretty ****ing cool. Reminds me of the movie Contact where the old guy tells Jodie Foster that an advances civilization would think in multiple dimensions as well. :thumbsup: 

I woulda been getting the dremal out for the same effect. blush


----------



## cvjoint

I would have done a custom fiberglass baffle if I had the time and lungs for it. No overlap just voluptuous shapes. The overlap with MDF works just as well though, it's cheap and time saving. 

*In car comparison AE vs Vifa 12"*
*FR*

The frequency response is unsmoothed since we're looking at low frequency data. Smoothing makes things easier to read which is key past 500hz or so as you can see. It's also closer to what we hear 1/3 octave but at low frequencies things look alike smoothed or unsmoothed.

AE Black 
Vifa Red










So the Vifa output is about 3db or so higher bellow 200hz and about the same up top. There are three sources for this higher output:
A bit under 1 db comes from the amplifier, more power. This amp should put 750w at 2.66 ohms on the AE and about 900w on the Vifa at 1.33ohms. The better modeling seen in the simulations should give the Vifa a 1 db advantage bellow 20hz but less the higher you go. So what does all this mean? Well the Vifa is simply more sensitive for sub and midbass use. I'm not sure why, but roughly 2db across the board 20hz-200hz is a lot. 

35hz and above the frequency response is almost identical in shape just shifted to reflect Vifa's higher sensitivity. Bellow 35hz things get interesting and that's partly why I went unsmoothed data this time. At 32hz or so there is dip in the Vifa response that is seen in the manufacturer data as well, but perhaps higher in my plot. Otherwise from 30hz to 24hz there is a lot more output from the Vifa, and then bellow 24hz more from the AE. 

Overall the Vifa looks better, a flatter tilt good for sub and midbass use and more output. Next question is whether this extra output comes at the cost of extra distortion. How much of it is the signal - fundamental - and how much is dirt - harmonic distortion. 

*HD*

HD @ 105 db
AE








Vifa









I won't comment on this too much, we have higher output tests so I will comment on those. There is also some resonance from my baffle at 60hz that gets excited more in cold weather and the Vifa was tested in a cooler climate. A good sign that there is some background noise is that the higher output plots show lower distortion. 

HD @ 110 db
AE








Vifa









This one has a lot less noise so let's see. A good way to see which speaker has the lowest distortion at high excursion is too look low at say 20hz. Distortion down there is usually motor dominated. AE is about 5.5% whereas Vifa is at 4%. Both subs are superb at this kind of output. Both are mostly under 1% from 30hz to 500hz despite where they are mounted. 


HD @ 115 db
AE








Vifa









At 20hz the AE is at 7.5% whereas the Vifa is at 4.2%. The bottom, 12hz-25hz suggests the Vifa has more stroke and it is cleaner for the same amount of output. There is however a resonance of sorts around 28hz where the Vifa doesn't perform as well and the AE is unusually good. The distortion over 30hz is again really good for both and mostly under 1% all the way to 500hz. 

These results mirror the simulation information which is a good thing, as expected. The Vifa has more low end grunt and less top end. The flatter response combined with a tad more xmax predicted better distortion down low and indeed it does. The one thing we can see with actual performance tests and not in Klippel plus TS parameters is resonance. The Vifa does have a minor problem between 25hz-35hz. This is present not only in the FR as a dip but also in the distortion measurements. Both subs have mostly 2nd order distortion which is great, not as offensive as the higher order products. 

*Final conclusion: Vifa is overall a better sounding driver, but only by a small amount, and surpassed only here and there where there is a resonance issue. *


I stopped at 115db because in some spots the output was dangerously close to 120db and that's when my mic starts clipping. For reference I had 6db more to go from the headunit gain, and about 26db in volume. Out of that 32db of headroom in the head I used 25db or so of it on music. Odds are the Vifas can hit 130db in this car but I won't try it.

EDIT: fixed the db to %thd conversions for the last batch of HD results.


----------



## Brian Steele

cvjoint said:


> At 32hz or so there is dip in the Vifa response that is seen in the manufacturer data as well


I wonder what's causing this? Could you do a close-miked FR measurement of the Vifa in free air, to see if the dip is still there? I thought that the dip was a measurement artifact...


----------



## cvjoint

Brian Steele said:


> I wonder what's causing this? Could you do a close-miked FR measurement of the Vifa in free air, to see if the dip is still there? I thought that the dip was a measurement artifact...


Good question, here's why I don't think it's a measuring artifact:
*It doesn't happen with the AEs. Same size sub, same install, same mic position
*I average over 28 mic positions for the frequency response, 14 at each ear in the driver's seat
*It's a low frequency phenomenon 
*The mic is about 1 meter away
*I'd think Vifa at least knows where to put the mic and they get the same thing
*Vifa's one spot proper placement and my averaged response give the same result
*Three different subwoofer play at the same time from different distances and it's still there

All in all I think the finding is fairly robust. If I ever get a chance to test it when the baffle comes out again I'll test it free air to verify.


----------



## Brian Steele

cvjoint said:


> Good question, here's why I don't think it's a measuring artifact


If it's not, and that's an actual characteristic of the driver, it does raise the question of what could possibly be causing it, whether or not that cause might be detrimental to the driver's characteristics in other ways, and the suitability of a driver as a subwoofer when it has a notch in its output @ 32 Hz. It could explain why the price is so cheap compared to the other Vifa neo drivers on the PE site...


----------



## cvjoint

Brian Steele said:


> If it's not, and that's an actual characteristic of the driver, it does raise the question of what could possibly be causing it, whether or not that cause might be detrimental to the driver's characteristics in other ways, and the suitability of a driver as a subwoofer when it has a notch in its output @ 32 Hz. It could explain why the price is so cheap compared to the other Vifa neo drivers on the PE site...


It's a part resonance. Speakers have many of these, some are better controlled than others. That is partially why you see little irregularities in a speaker's frequency response. It's hardly unusual. Luckily the distortion in that spot is not too bad, you can theoretically equalize the response without a big toll on distortion. The AE has a similar dip a few Hz down. I wouldn't say it ruins the speaker or throws it in a lower price bracket.


----------



## cvjoint

thehatedguy said:


> I have it on record from a good friend of mine that the NE8s are beasts when placed in an enclosure.
> 
> I wish I could hook you guys up on the NE line, but the close out price is the same as wholesale...only retail gets free shipping over $100 and wholesale gets free shipping over $500.
> 
> Was the NE 6 tested by Vance? I don't remember if it was. I would be curious if they are more than Illuminator Jrs just on looks.


*NE180W-04* 
BL 4.2mm
CMS 2.8mm

LE looks the same as the 12" but much lower with 0mm magnitude of .22 or so.


*Vifa NE 65W*
BL 1.8mm
CMS 2.7mm


Both Klippel results are for the standard 10% distortion limits. 

LE is centered at .085, it is almost a basic downward sloping curve. It curbs a little on the negative side.


If you ask me none of the NE drivers are class leading. I do however like their performance and sex appeal/lb,$.


----------



## Brian Steele

cvjoint said:


> It's a part resonance. Speakers have many of these, some are better controlled than others. That is partially why you see little irregularities in a speaker's frequency response. It's hardly unusual. Luckily the distortion in that spot is not too bad, you can theoretically equalize the response without a big toll on distortion. The AE has a similar dip a few Hz down. I wouldn't say it ruins the speaker or throws it in a lower price bracket.


http://www.parts-express.com/pdf/264-1120s.pdf

That looks like an 8-10dB notch @32 Hz, big enough to put a noticeable bump in the impedance response at that frequency. I dunno.. looks like it's something I'd notice. Point might be moot at this point though - the PE site lists this driver as no longer available.


----------



## cmahood

Oliver said:


> To bad this car is a drop top [sad face ]


Yeah, don't spend too much money on components, you are never going to get a great result with the rag top and the 9K motor. Just too much noise.


----------



## cvjoint

Yeah the drop top really kills the fun. I spend some of my weekends on Balboa Peninsula so I ride the PCH HWY 1 to get back home. At 130am like tonight I come back with the top down, open air. All I can hear is that nasty 2.0 liter Indy-car style ripping short gear after short gear. There is hardly anybody on the roads so you can heal and toe at a green light sneak it into first, and slide that taught s2000 ass as you turn. As soon as that's done the revs get in the 9k neighborhood and that's when things get even worse. The rev counter lights up like a pure breed race car and tells you a split second is all you have to move to the next gear, you pull, there is a metal on metal feel as the gearbox drops to no less than 6,500rpm hardly giving the tires a chance to catch for the next 1,000 rpm. Meanwhile you are sitting there as if possessed, that stupid beach air is ramming into your face, limbs connected to the chassis as if they are umbilical cords. 

Adding music just makes it worse. There is that certain lack of reflections from the midrange and tweeters which we all love, and the bass drivers no longer compress your eardrums as they do with the top up. The car requires so much stinking attention to drive, sneak pull, sneak pull, those revs hardly tire. There are those dash controls that require no line of sight to operate but then a shuffle action seems just like the ticket. It's almost like the radio but higher quality at the same time letting the jukebox change songs at random. It's that lack of control that gives it an innate charm in a way. All the songs, even the ones you like least sound pretty good tonight. 

Your senses get overwhelmed with the smell of clutch, brakes, tires, ocean air, and a familiar tune knocking the air out of your chest. It's a stupid thing this motoring and music bathing all in one swoop.

What is this huh, you mean you can have the same car convertible, soft top and hardtop at the same time? Stooopid design:


----------



## cmahood

The best thing about the S2000 is that anyone who wants one can afford one. Or you can get 90% of the fun with a Mazda Miata. Salivating over 240hp is sooo 2001.


----------



## cvjoint

Brian Steele said:


> http://www.parts-express.com/pdf/264-1120s.pdf
> 
> That looks like an 8-10dB notch @32 Hz, big enough to put a noticeable bump in the impedance response at that frequency. I dunno.. looks like it's something I'd notice. Point might be moot at this point though - the PE site lists this driver as no longer available.


Yep, sure is. It backs up the fact that it's not a measurement anomaly. Now, as far as the impact take a look at the XXLS to compare.
Vifa's average output is about 88db on that graph. It gets down to 76db on axis at the trough. That's a 12db drop. The XXLS which has no problems down low manages an output of 80db, however it's natural output is 90db. That's a 10db drop. 

You can think of the Vifa's trough as dip or as a natural rolloff plus bump at 25hz. If you cycle between the AE and Vifa graphs there is dip in both graphs. Which one would you rather equalize more, the Vifa at 32hz, or the AE at 25hz? Which one is more likely to have lower HD post equalization?

PE cleaned them out like I thought. I saw the special was there for a long time which is unusual if you just want to garner interest in the product. That's precisely why I got rid of my subs on such a short notice, I felt like they were clearing them out. When I bought mine there were 3 left in stock after me. I wonder who got the other three? 

My next guess is that they will have a heatsinked option selling for $240 or a more. That's roughly where it should be sitting price wise in comparison to the XXLS and given the fact that neo motors cost a lot nowadays.


----------



## cvjoint

I lost the Anarchy speakers. There will be no further testing for a midbass driver. At some point I may buy the Illuminators and rework my door panels to fit them.


----------



## ErinH

cvjoint said:


> I lost the Anarchy speakers. There will be no further testing for a midbass driver. At some point I may buy the Illuminators and rework my door panels to fit them.


You lost them? As in physically misplaced them? 
Why no further testing? 

Not sure what the post means. Unless you're just saying the illuminator is such a beast youre going with that.


----------



## cvjoint

bikinpunk said:


> You lost them? As in physically misplaced them?
> Why no further testing?
> 
> Not sure what the post means. Unless you're just saying the illuminator is such a beast youre going with that.


I went to an S2000 meet. I took them out of the trunk to show off the Vifa subs. I forgot to put them back in the trunk before driving off and I'm pretty sure I was the last there. Somebody must have found them in the parking lot and took them. It would be nice if they turned them in to security but it didn't happen. 

I don't feel like buying the Exodus, again, I don't even know if they are noticeably better than the SLSs. Based on your results they may be only .2mm or so better in BL and the SLS suspension looks beefy enough. The Illuminator would be a sure improvement but I must be willing to cut the door panels to pull them through.

So it appears the 7" Illuminator could hang with the 10" Excel Magnesium in linear output. Roughly half the surface area on the Scan, but then roughly twice the linear throw as well. Of course the Excel would obliterate it in sheer SPL if you are willing to tolerate over 10% distortion but that's not how I play my speakers anyway. That makes the Illuminator really really appealing. If I could get the midbass quality I had in the Accord in this little S2k I'll be very happy.


----------



## SSSnake

CV,

I know we started talking about this is the AE thread but is there a way to go with kicks and/or an enclosure in the door (not sure if the inner door skin is removable on the S2000)? The reason I ask is:

If you can get a true .25cubes after speaker/port displacement you could theoretically go with a ported HE driver and get even less distortion through excursion reduction. I have these graphs laying around so they could be used for discussion. The grey plot is the illum and the yellow is a B&C 8NDL51 (I think I remember that you can't fit the eight but the B&C 6.5s would have a similar curve just lower max SPL capability)...

Anyway the plot below is the transfer function.










The illum reaches a little deeper in this graph but not much. If you take a look at excursion (see below) you start to see the advantage of ported.










Much less excursion below 200hz. WHich should tranlate into much less distortion.

Then the examine the output at 150W. This should give you a little less thermal compression for a given SPL (both motors should shed heat well - I would give the edge to the Illum but with the lower power requirement for the B&C it should outperform the illum in this area).










Group delay (not pictured) is good for both 3ms for the Illum sealed and 6ms for the proted B&C. So no real worries there...

The only problem I see is port velocity. It will be tough to get it big enough to handle full power without whistling but I have had good look with aeroports in this regard.

If I remember correctly you are looking for a lower xover freq than I. If you want to get to 60hz it starts becoming pretty tough. The Illum would likely be better in that application. .35 cubes and a 60hz tune would place your -3db freq right at 60hz anechoically. In car it would likely be a good bit stronger. But in this case the port velocity issue is even tougher. Anyway food for thought.


----------



## BigRed

George. That sucks that the speakers weren't turned in. Reminds me of the bad luck you had with cars running over your amps at the autobach meet


----------



## cvjoint

I thought about porting the B&C when I had it a lot. It's true that the 8" won't fit but the 6" still has oodles of power handling and unlike other high sensitivity pro audio drivers it has some excursion ability as well. 

I think that your point is well made. For a similar level of output 70hz thereabouts the B&C driver itself will be at low enough excursion to beat the Illuminator in non-linear distortion. The vented design does however have its shortcomings, and they all get exacerbated with a higher tunning frequency. 

1. Vent tunning is out of phase with the driver's output. This is a good enough concern with subs, let alone a midbass that has to be blended in with a driver bellow it. 

2. Midrange output can bleed through the port. Again in subwoofers it can be a concern if crossed somewhat high, in a midbass even more so. 

3. The consistency of the design is highly dependent on ambient conditions. In the mobile environment the temperature and moisture variations can be drastic, therefore so will the tunning of the box. I don't think it's enough to push the tunning where excursion will be a problem but there is more variance nonetheless. 

4. Looking at the excursion plots around the 125hz area, the B&C is at 4.5mm whereas the Illuminator is at 5.5mm. The throw abilities of the Scan are so much better that distortion at 125hz is likely to be twice as high for the B&C. Keeping in mind that we are less tolerant of harmonics in this region the Scan might have a definite advantage where it matters more. Near the HP the Scan will get help from cabin gain and distortion is less audible. If I want to keep my distortion at 125hz bellow 1%, I won't even begin making use of the vented box advantage. 

5. The vented box will be small. This means the box is more pressurized especially as opposed to true IB. In a door this could be problematic. The midrange leaking is also exacerbated in a smaller vented box, as are port noises etc. The small vented box is first required by the driver's parameters, and second by the physical limitations of a door. 


I do not know the weight that should be assigned to all these drawbacks vs. the gains. All in all I lost lots of time modeling the B&C in vented arrangements and I think it's worth the shot. Personally, I didn't feel the gains would be worth it once I was able to get the SLS at bellow 1% distortion @ 115db in a very simple IB arrangement. I would sure love to get my hands on a vented midbass car and test it thoroughly I just wouldn't risk my resources, especially with a golden IB performer like the Illuminator. 


@BigRed I really don't learn from my bad experiences do I? Luckily it has been cheap merchandise so far.


Edit: As far as kicks go the S2000 has a 3.5" or so square vent in the car's kick. I could use a Faital 4" in there vented in the chassis no problem after relocating all the major vehicle harnesses. A midbass is out of the question. Even if I made a 7" cutout in the kick sheetmetal there isn't enough depth or room in there for a midbass. The car is really narrow, if it wasn't for the long hood the S2000 would be a miniature car.


----------



## cvjoint

Comparison between 2 Honda S2000s with stock speakers and mine. Note that both of these guys had an aftermarket headunit. Both had *bass boost* up and you can see that at about 55hz, one guy has a boost in the treble as well at 18khz or so. 

My plot is in black. When set on my custom flat tune it sits at +-2.5db, whereas oem drivers with some bass boost muster +-10db. Subjectively there are a few things that would be unpleasant, like very little output bellow 50hz, a lot of variation between 400hz and 2khz would significantly distort the true signal in the meat of the midrange, and finally the tweeter rolloff starting very early at 7,500hz. These are both 2003+ S2000s improved oem systems. My model year did not have tweeters from factory and would probably look way worse.


----------



## Ultimateherts

cvjoint said:


> I went to an S2000 meet. I took them out of the trunk to show off the Vifa subs. I forgot to put them back in the trunk before driving off and I'm pretty sure I was the last there. Somebody must have found them in the parking lot and took them. It would be nice if they turned them in to security but it didn't happen.
> 
> I don't feel like buying the Exodus, again, I don't even know if they are noticeably better than the SLSs. Based on your results they may be only .2mm or so better in BL and the SLS suspension looks beefy enough. The Illuminator would be a sure improvement but I must be willing to cut the door panels to pull them through.
> 
> So it appears the 7" Illuminator could hang with the 10" Excel Magnesium in linear output. Roughly half the surface area on the Scan, but then roughly twice the linear throw as well. Of course the Excel would obliterate it in sheer SPL if you are willing to tolerate over 10% distortion but that's not how I play my speakers anyway. That makes the Illuminator really really appealing. If I could get the midbass quality I had in the Accord in this little S2k I'll be very happy.


I guess my question why there is no testing of Tang Band midbass?


----------



## cvjoint

Ultimateherts said:


> I guess my question why there is no testing of Tang Band midbass?


Well, here's the thing. The TB 7's are as deep as the Illuminator. That means for all practical purposes they are in the same category and running directly against each other. 

Unlike the Illuminator we don't have that much information on them. Trust me, I tried. I even emailed TB to get Klippel results if they had any, here is what I got in response:

_Thanks for your inquiry about Tang Band driver.

Take this opportunity, we would like to introduce ourselve, TB speaker, has been in speaker related field more than 22 years, we moved our factory to Ningbo China since 1999 for competition concern. We have very good team at product research and development, quality control, please refer our website Tangband Speakers -> news, then you can see our new products.

We don't have Klippel system, what we used is LMS. Attached is datasheet of W6-1139SI for reference._

A datasheet is ok but I had that and it tells me nothing about what happens to a driver once it gets more than 1w. The only large signal test we have is Npdang's 8" comparison. The TB 8" has a massive motor, by far the best, 20mm or so of pure throw. It seems like TB can afford to put lots of magnet on that baby and it shows. On the other hand the suspension only musters 7mm of throw resulting in an xmax of 7mm. There is no inductance treatment as far as I can tell and that's worrisome too. 

In order for me to buy a TB 7" I can bring together what I know about its performance and what it needs to deliver to match the Illuminator. 

If the TS parameters are true, the 6.5" sub needs more than twice the power the Scan needs for a similar amount of output. At that output in needs to have nearly 1mm more xmax to keep distortion the same as well. 

So what are the chances the TB can handle at least 300w continuously and test at an xmax of 10mm just to match the Scan? Even if it does the Scan has a textbook inductance curve and it seems the TB have absolutely no inductance treatment. The baskets also clearly don't flow as well either as they are all stamped. 

In short, I don't trust it tests this good. If Erin ever Klippels one I'd love to see it though but I'm not holding my breath.


----------



## ErinH

Is be happy to test one. Just gotta find a way to get it and PE has offered zero in the way of price assistance.


----------



## cvjoint

Currently fighting some nasty power supply noise, I think,:
http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/115643-noise-problem-has-me-beat-need-help-troubleshooting.html#post1450177


----------



## Ultimateherts

cvjoint said:


> Well, here's the thing. The TB 7's are as deep as the Illuminator. That means for all practical purposes they are in the same category and running directly against each other.
> 
> Unlike the Illuminator we don't have that much information on them. Trust me, I tried. I even emailed TB to get Klippel results if they had any, here is what I got in response:
> 
> _Thanks for your inquiry about Tang Band driver.
> 
> Take this opportunity, we would like to introduce ourselve, TB speaker, has been in speaker related field more than 22 years, we moved our factory to Ningbo China since 1999 for competition concern. We have very good team at product research and development, quality control, please refer our website Tangband Speakers -> news, then you can see our new products.
> 
> We don't have Klippel system, what we used is LMS. Attached is datasheet of W6-1139SI for reference._
> 
> A datasheet is ok but I had that and it tells me nothing about what happens to a driver once it gets more than 1w. The only large signal test we have is Npdang's 8" comparison. The TB 8" has a massive motor, by far the best, 20mm or so of pure throw. It seems like TB can afford to put lots of magnet on that baby and it shows. On the other hand the suspension only musters 7mm of throw resulting in an xmax of 7mm. There is no inductance treatment as far as I can tell and that's worrisome too.
> 
> In order for me to buy a TB 7" I can bring together what I know about its performance and what it needs to deliver to match the Illuminator.
> 
> If the TS parameters are true, the 6.5" sub needs more than twice the power the Scan needs for a similar amount of output. At that output in needs to have nearly 1mm more xmax to keep distortion the same as well.
> 
> So what are the chances the TB can handle at least 300w continuously and test at an xmax of 10mm just to match the Scan? Even if it does the Scan has a textbook inductance curve and it seems the TB have absolutely no inductance treatment. The baskets also clearly don't flow as well either as they are all stamped.
> 
> In short, I don't trust it tests this good. If Erin ever Klippels one I'd love to see it though but I'm not holding my breath.


Which TB are you talking about? Model number?


----------



## cvjoint

Ultimateherts said:


> Which TB are you talking about? Model number?


W6-1139SI neo, beefy suspension and 13mm xmax promises.


----------



## cvjoint

Fixed the ground issues so I went ahead and did some final tests:

*FR*










I boost the sub a bit (up to 16db depending on the song, etc). Dop down generally requires full tilt past 45mph. Anywho, frequency response wise this car can be linearized very well. 

*HD right*









*HD left *










This car has two big problem areas. For the right side frequencies between 400hz and 800hz have to be boosted a lot. 630hz gets boosted the most, 6.5db and it shows, that's the highest distortion area for the right side. 

*Fixes:*
I've done over 4 Honda S2000s by now and I can tell you that wide dip from 400hz to 1000hz or so is present in all of them, even with door speakers reaching up to a tweeter. Dashmat, or weird waveguides are not gonna save this car. 
The only thing that works is to get really low distortion speakers so that when boosted the distortion is still low because it starts super low. 

On the left side this problem doesn't exist odly enough. The problem on the left is midbass. The midbass has a dip at 125hz and requires *9db* of boosting.  Even the SLS cries for help with this much boost on tap. I wish I tested the other S2000 cars' left speakers but I did not. I only test right speakers FTL.

*Fixes:*
Don't know. My first impulse is to test it again without the door panel on, maybe the midbass gets all trapped and canceled in the door. Maybe it's all door rattles. This is a much bigger issue than the midrange distoriton on the right side. Even a more capable 7" like the Illuminator is not gonna like 9db of boosting, and my door hates it. 

For now I'm cutting both left and right at 125hz and 630hz until I find solutions. I find it more appealing to still have left and right matching and a bit of frequency response dip rather than hear all this distortion. This is where my black art skills as a tuner come into play. What tradeoffs to make?


----------



## subwoofery

cvjoint said:


> ...This car has two big problem areas. For the right side frequencies between 400hz and 800hz have to be boosted a lot. 630hz gets boosted the most, 6.5db and it shows, that's the highest distortion area for the right side.
> 
> *Fixes:*
> I've done over 4 Honda S2000s by now and I can tell you that wide dip from 400hz to 1000hz or so is present in all of them, even with door speakers reaching up to a tweeter. Dashmat, or weird waveguides are not gonna save this car.
> The only thing that works is to get really low distortion speakers so that when boosted the distortion is still low because it starts super low.
> 
> On the left side this problem doesn't exist odly enough. The problem on the left is midbass. The midbass has a dip at 125hz and requires *9db* of boosting.  Even the SLS cries for help with this much boost on tap. I wish I tested the other S2000 cars' left speakers but I did not. I only test right speakers FTL.
> 
> *Fixes:*
> Don't know. My first impulse is to test it again without the door panel on, maybe the midbass gets all trapped and canceled in the door. Maybe it's all door rattles. This is a much bigger issue than the midrange distoriton on the right side. Even a more capable 7" like the Illuminator is not gonna like 9db of boosting, and my door hates it.
> 
> For now I'm cutting both left and right at 125hz and 630hz until I find solutions. I find it more appealing to still have left and right matching and a bit of frequency response dip rather than hear all this distortion. This is where my black art skills as a tuner come into play. What tradeoffs to make?


You could do a middle ground for 630Hz and 125Hz... 
Since you have to boost 630Hz by 6.5dBs on the right side, why not boost the right side by 3dBs and cut the left side by 3.5dB? 
Same thing for the 125Hz problem on your left side... You could try 3dB of boost on the left side and cut your right side by 6dB? 125Hz is usually a problem in most cars and it seems like you have a small peak around that freqs (on your graph) with the combined channels. 

Kelvin


----------



## cvjoint

subwoofery said:


> You could do a middle ground for 630Hz and 125Hz...
> Since you have to boost 630Hz by 6.5dBs on the right side, why not boost the right side by 3dBs and cut the left side by 3.5dB?
> Same thing for the 125Hz problem on your left side... You could try 3dB of boost on the left side and cut your right side by 6dB? 125Hz is usually a problem in most cars and it seems like you have a small peak around that freqs (on your graph) with the combined channels.
> 
> Kelvin


That upsets the left right balance and therefore the soundstage. I tried and it and it makes the higher output side more dominant. That is a choice, making a summed FR ok at the cost of left and right integrity. The midbass tweak doesn't upset the balance as much, I guess it's more omnidirectional but still noticeable.


----------



## Knobby Digital

What are the passbands of the drivers that cover the range that the problems are in?


----------



## cvjoint

Knobby Digital said:


> What are the passbands of the drivers that cover the range that the problems are in?


sls 6.5 covers 63-200hz
Faitals cover 200-6.3khz

The Vifas are back at PE. $262 price tag.  The only difference is the 8 ohm coil which I'm guessing is worse for most applications in car audio. The wiggle in the impedance curve and drop in FR is near 35hz where I found it to be in my testing. My results now align closer to the white sheet than before.


----------



## ErinH

subwoofery said:


> You could do a middle ground for 630Hz and 125Hz...
> Since you have to boost 630Hz by 6.5dBs on the right side, why not boost the right side by 3dBs and cut the left side by 3.5dB?
> Same thing for the 125Hz problem on your left side... You could try 3dB of boost on the left side and cut your right side by 6dB? 125Hz is usually a problem in most cars and it seems like you have a small peak around that freqs (on your graph) with the combined channels.
> 
> Kelvin


The problem with boosting is that it alters the sound. Boost to change, cut to resolve. I see this stated and it seems to hold true. Something about boosting the signal always seems to change the tonality for the worse, whereas cutting it just seems to lessen the effect. There's a paper on this somewhere in this vast wasteland called my brain, but I can't remember where I saw it.


----------



## Niebur3

bikinpunk said:


> The problem with boosting is that it alters the sound. Boost to change, cut to resolve. I see this stated and it seems to hold true. Something about boosting the signal always seems to change the tonality for the worse, whereas cutting it just seems to lessen the effect. There's a paper on this somewhere in this vast wasteland called my brain, but I can't remember where I saw it.


But if you cut all frequencies (except, say 1), aren't you just in theory boosting the one frequency you did not cut? Aren't you just changing your baseline from say 0dB to -1db (leaving the single band at 0dB), so if you left all others at 0dB, and boost the one by 1dB, it should sound the exact same, just overall 1dB louder.....correct?


----------



## ErinH

Hmmm... I'm not sure how to take that, to be honest. In our case, we never do anything like that. The idea here is that we'll likely be making changes in various amplitudes for various frequencies. What you're suggesting is more along the lines of lowering the level for a driver and boosting one. Is it the same? Well, not technically, but pretty much. The difference in what you're talking about what I'm talking about is real world use. For those who are making boosts, that 3.5dB is HUGE and you walk in to distortion/headroom limits much sooner than you do if you make a cut. I believe that's where the real issue lies. Not so much in minor boosts here and there.

Realistically, when have you been faced with that kind of decision anyway? If you have to use that much EQ, you need to evaluate your system. lol.


----------



## BuickGN

Just wanted to say I'm loving this thread. I have nothing technical to add, it's way over my head but I'm learning from it.


----------



## cvjoint

I'm with Niebur3, whether you boost or cut it doesn't matter if you achieve the same target curve. It is the relative boost of a frequency in relationship to the others that drives distortion measurements. 

In terms of the difference from the fundamental to any harmonic, it will always be the same for a given spl at a given frequency. That is dictated by the ability of the speaker to reproduce a frequency at a certain spl. That's why nonlinear distortion cannot be improved with an Eq.

If you cut a frequency but keep the rest fixed you change the target curve and that will reduce nonlinear distortion but will induce more linear distortion aka your frequency response will have a huge dip. That's what I'm doing now but it's the lesser of evils type approach. 




A 3.5db deviation from flat is not only common in a car, it's average from what I've observed testing cars in So.Cal. A good home audio system will be lucky to only have 3.5db variation throughout it's FR. In the case of the Honda S2000 there is a dip 400hz-1000hz that is wide and deep regardless of whether you use pillar or door mounted mids on the right side. I wouldn't say the system is to be evaluated but rather this is routine in the car environment.


----------



## cvjoint

I have two proposed changes for future upgrades. Go ahead and rip it apart guys, well with the exception of the midbass switch which I already settled on and can't change my mind anymore. 

Change no. 1 Peerless SLS 6.5" to Scan Speak Illuminator 6.5"

The reasoning here is the following. The Illuminator is quite simply the best testing 7" on the Klippel. Erin's testing showed 9.2mm of throw while Vance's showed 10mm. The SLS on the other hand can only muster 7.5mm of linear throw IF that suspension is at least as good. That's a big if since the suspension is usually the limiting factor for these high throw drivers. Furthermore, the Illuminator has a really good amount of cone area compared to the SLS. More throw and more cone area = lots more output. 

The small signal parameters also look very good. It models nearly flat to 63hz and with very high sensitivity. This could easily be 4.5db higher than the SLS. It also seems to have one of the best QTS for IB in a 7", at .45 it is really good. Among the high throw drivers it's actually the highest. 

I will have to cut the door for it, but as seen in my distortion measurements this might alleviate the huge drop in output at 125hz that's probably due to door interactions. It's also 1.5lbs lighter due to neodymium use, has a better power rating (not really a concern for the SLS imo), and can be crossed higher if needed. 










Change no. 2 Clarion XH amplifiers to JL XD (three xd600/6)

This I need feedback on more, because I haven't made the purchase yet. 

*Advantage 1: higher efficiency (2ohm max load ratings)
*Clarion 66.9% for the G/H mono based on G/H Arc 300.2 review, 52.5% for AB 4 channels
Jl 83.6% *
This is a great improvement. I am stuck with a tiny battery that dies if I don't move the car every 4 days, and an oem 105 Denso alternator to maintain reliability and high output at idle. Efficiency will translate into more power and less dimming. 

*Smaller footprint
*Approx 1/2 the volume displacement.* This is great because I will be able to move them farther from the chassis and eachother so I don't get weird noise problems again. It also means the subwoofers have a cleaner path to the interior. 

*Better control
*The remote gain for the Jl attenuates 100% at min* whereas the Clarion only attenuates 10db. That's a big difference. Furthermore, *the JL remote allows chaining* which means I could get two knobs, one for the subs one for the midbasses and adjust depending on mood, song, conditions etc. 

*Ability to switch to 5.1 audio 
Having 18 channels of power available could allow a quick switch to MS8 setup in the future. 

*Total power is about the same
Clarion 4ch 14.4v, 50hz test tone, all channels driven, 1% THD:
*101w @ 4 ohm 
145w @ 2 ohm, 160w (1khz test tone)*
[email protected] 8 ohm
Clarion monoblock 1ch, 12.6V
460w @4 ohm

JL 6ch 13.8v, all channels driver, 1% THD:
*67w @ 4 ohm
123w @ 2 ohm*

*That's a max of 2130w @ 2ohms for the Clarions together, assuming 850w @2ohm for the monoblock, no test available. Jls would put out 2214w and at a lower voltage. *

*Weight
*Clarion 27lbs*

*JL 5.8lbs x3 = 17.4lbs*

*Frequency response
*Clarion -.5db @20hz, -.5db @20khz*
*JL -1db @20hz, -1db @20khz*

*Signal to noise ratio
Clarion 78db 1w 4 ohm, which should amount to *98db 101w 4 ohm*
*Jl 67w 4 ohm 97db*


*Conclusion:*
According to RC, amplifiers with similar frequency response, power, and THD+N should sound about the same. Here we can see the JL is half a decibel down at the ends of the FR, has about 1db lower S/N ratio and power is the tested at the same thd and it's way under 1% for all unless driven hard. That means for all practical purposes *they should sound the same,* 1 db is the most difference one can hear and the overall power is the same. 

Then there would only be the benefits, which are enormous:
*1/2 decrease in volume displaced
25% more efficient
10lbs lighter 
More flexible remote control*










Links for tests:
http://mobile.jlaudio.com/pdfs/XD%20Review/XD_Review.pdf

Clarion XH5410 4-Channel Amp Review - Amplifier Reviews - Car Audio and Electronics

PASMAG | PERFORMANCE AUTO AND SOUND - Clarion XH7110 Amplifier - Page 2


----------



## subwoofery

Knew it was only a matter of time before you switch to the dark side of the force... 

Kelvin


----------



## cvjoint

subwoofery said:


> Knew it was only a matter of time before you switch to the dark side of the force...
> 
> Kelvin


Yeah, I've been pretty stubborn to switch out of AB class. I've been doing the class G/H for a while because you simply can't **** that one up. I always believed class D amps could sound as good but I wasn't sure how to check whether a particular class D amp has the goods. Like your sig says, amps do not sound the same.

Early class D amplifiers always seemed like a risk to me. Without 3rd party testing you simply don't know the corners they cut to achieve high efficiency. Most of the first wave buyers of class D were obsessed with efficiency as the sole goal. If you combine the aspects of amplifier differences from the RC challenge with 3rd party testing I think you can get a good picture of how it will sound (or not sound for that matter). Another clue is that JL, and Manville seem to regard the HD class D lineup as their flagship, not the AB dinosaurs. Safe to say this gives me courage enough to try. Besides, I could bring the gross weight of this audio setup to under 90lbs!! Combined with the savings from the Scans and a few tricks I have up my sleeve 85lbs is achievable.


----------



## cvjoint

Another smashing test of the Scan Illuminator:

HTGuide Forum - SS 7" Illuminator

Similar results to Zaph's, although not exactly copies. There is a lot less distortion in these at 1,200hz. Seems like a great 2way or 3way driver no matter how you look at it. Bellow 1% up to 6khz from an oversized 7" aluminum cone is fantastic. Makes you want to believe that clove patern on the cone actually does something.


----------



## t3sn4f2

cvjoint said:


> Another smashing test of the Scan Illuminator:
> 
> HTGuide Forum - SS 7" Illuminator
> 
> Similar results to Zaph's, although not exactly copies. There is a lot less distortion in these at 1,200hz. Seems like a great 2way or 3way driver no matter how you look at it. Bellow 1% up to 6khz from an oversized 7" aluminum cone is fantastic. Makes you want to believe that clove patern on the cone actually does something.


And a _much_ better cone material for a door install than the paper version.


----------



## ErinH

cvjoint said:


> Another smashing test of the Scan Illuminator:
> 
> HTGuide Forum - SS 7" Illuminator
> 
> Similar results to Zaph's, although not exactly copies. There is a lot less distortion in these at 1,200hz. Seems like a great 2way or 3way driver no matter how you look at it. Bellow 1% up to 6khz from an oversized 7" aluminum cone is fantastic. Makes you want to believe that clove patern on the cone actually does something.


Now I think people are starting to see why I'm so fond of mine. 

I've currently got them as a 2-way setup now while I transition to a new midrange. Great drivers. Halfway considering keeping them in 2-way application. Just have issues above 1k with them in the kicks due to my legs.


----------



## SSSnake

My pair arrived Friday.

Erin,

What tweets r u running? They might as well match as well. Good to hear about the 2 way comment. I have no desire for a three way front stage. At least not today


----------



## ErinH

Right now it's the 3/4" ring radiator illuminators. I've got the dome versions as well to play with. Alligator clips on the tweets.


----------



## cvjoint

A face-off I'd like to see is the Illuminator vs. B&C from 100hz up. I've always loved the B&C over that range over any other driver but the Scan seems to have the that je ne sais quois, actually I know what it is "pure sex" over the whole spectrum. We might have here a driver that can beat the SLS bellow 100hz and the B&C above 100hz. Total domination. The one problem I have with this test is that I'll have to pull the Scan through the door panel which really isn't fair for the B&C. I wish I tested them without a door card. Maybe I can test the SLS with and without a door card and extrapolate the change from the door panel.

For you guys running 2 way you wont' miss a thing outside of staging. These seem low enough distortion to cross with a 3/4 dome up top. Well, polar response would be just ok above 2khz.

I'm thinking of getting the Neo 10s and basically cross where I get lower overall distortion. Might be somewhere around 500hz from what I can tell, it would sure be a shame not to run the planar down to 200hz but the gains in low distortion could be fantastic.


----------



## cvjoint

Not a good test for the planars. They seem to have worse decay, thermal compression, and non-linear distortion when tested Linkwitz style with shaped tone bursts:

Spatial distortion

You should note that the evidence is not that clear because he uses different power levels and does not account for the efficiency of the drivers, but nonetheless he does say reducing output did not improve some of the tests. 

Looking at Zaph's CSD plots vs 3/4 domes it's seems that the domes decay quicker than the planar. The 1" domes are more inline with the BG. This brings into question whether the planars really decay quicker, the evidence so far seems to show they decay slower for a driver that can be crossed equally low of standard technology (dome). 

A noteworthy feature of Linkwitz's test is that they are tested at 5w or more so you get to see more realistic performance. 

I'm going to halt switching to Neo10 + AMT tweeter until I see some favorable performance from the new techonologies under more than 1w.


----------



## ErinH

George. Your midbasses are here. Just not had a chance to do anything with them yet. Halloween and an open house have kept me busy. 

PM coming.


----------



## cvjoint

I'm letting go of the idea of teaming up the BG Neo10 + AMT tweeter. Looking back at the tests the Faital line array is really really low distortion everywhere. I've also not been able to make these mids cringe, ever. With the Neo 8 crossed at 200hz it was easy to get it to the cry point. The Vifa supertweter is also really robust, with a large coil and heatsink cooling. Output wise and non-linear distortion wise this combo is hard to beat.

With that, I'm going to devote my energy to make these pillars stage better. I've already lowered the crossover point from 6.3khz to 5khz. This way the Faitals are only -5db down at 45 degrees off axis at worse so the polar response is amazing. The Vifa 3/4 dome also has impeccable decay compared to the mids. 

I will make three big changes:
1. flush mount the tweeter
2. make the edges of the pod really round and smooth on the top, bottom and windshield side. This idea is based on Patrick's improving the soundstage for $2.
3. on the sides I have a little trick. This is the only part of the pillar pod that has early reflection problems. The music deflects of the the side windows and likely makes for a small soundstage. I bought some aluminum plates. I will machine them so that they make a baffle for the Faital line array and then bend about 1inch or so of it towards the windows. Next I will lay some acoustic foam on them to absorb the wave. 










The yellow part is near the windshield. It's almost parallel to the speakers so it requires no attention. The light blue sides do not present any early reflections either. Thanks to the line array properties the top and bottom dispersion is restricted so there are few dash and top reflections. The red part is the one that is problematic. The aluminum sheet from under the Faitals would extend to the window to form a smooth transition. Secondly I can put a 1 inch foam layer on it to absorb the wave. At 1khz and up it would be fully absorbed. It would be absorbed to a smaller extent down low. 

I've seen this type of approach in Gary Summers's car and Duckymcse's. Both of them image really good. Mine images really good for what it is, and I think it's because 3 out of 4 sides are well taken care of already.


----------



## SSSnake

Why is the yellow shaded area not a problem. It doesn't appear to be flush with the windshield or parallel with the windshield (could be just the picture but I would be surprised). It seems to me that as narrow as the baffle is you would want some type of treatment in the yellow area as well. Maybe a foam to attenuate any reflections/diffraction in the area.


----------



## cvjoint

SSSnake said:


> Why is the yellow shaded area not a problem. It doesn't appear to be flush with the windshield or parallel with the windshield (could be just the picture but I would be surprised). It seems to me that as narrow as the baffle is you would want some type of treatment in the yellow area as well. Maybe a foam to attenuate any reflections/diffraction in the area.


Good catch, well, the driver and passenger pods are both aimed at the driver. The one on the driver's side is parallel with the windshield but the other is not. Thinking back maybe I should have build both of the pods facing the middle of the car. I have good enough dispersion properties to pull it off. 

Practically I can't extend the pods towards the windshield because it blocks my view. On the passenger side where it would be needed there is also an airbag that needs clearance to pop out. 

I suppose I only have one choice, which is to extend the pod baffle towards the window on the driver's side pod only. That has the worse early reflection problems. If I do this by absorbing though, doesn't it change the dispersion pattern of the pod? Am I not trading off dispersion to get better imaging? Aren't they both required for proper imaging, great dispersion without early reflections? What a mess. Maybe I should just extend the baffle towards the window, have a more smooth transition without absorbing. That would prevent deflection and allow for the pollar paterns to be the same across left and right.

Here is a better picture from when I had the planars:


----------



## cvjoint

More on the amplifier search. 
Check out the frequency response of a typical Class D amplifier by impedance load according to (CA mag.):










That means you could have swings of 5db using a tweeter bridged vs. at 4 ohms with a class D amplifier. 

Here is the bit from the review:
"Class D amps switch between positive full output voltage and negative full output voltage at a very high frequency. To keep this energy from affecting the speaker, they use an internal passive filter. The passive output filter forms a lowpass crossover sitting between the amplifier outputs and the speaker terminals. This filter causes a problem when it interacts with different impedances, since the filter tuning works for just one particular impedance. While the exact filter varies with each amp, all Class D amps typically exhibit some version of this problem. Here’s a typical good quality Class D amp I recently measured:..."

Full test was here, it was a comparo between unamed class d amp and Alpine PDX.
Alpine PDX-F4 Review - Amplifier Reviews - Car Audio and Electronics


Looks like I'll have to do a lot of work to pick amplifier replacements. Class D is tricky after all.


----------



## ErinH

Why not build a measurement rig to measure the FR/THD/IMD of various amps? A basic setup could consist of a simple line level attenuator like the one linked below in line with the RCA's, rightmark, and... that's it. 

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=266-244

Could run them in series for a 24dB attenuation. This should suffice for most amps intended for mid/tweeter (ie: no sub... high power situations). I didn't do the math, but feel free to see if that's enough attenuation. Most soundcard inputs accept up to about 1v in before issues arise. 


Even if it's not absolute (which, I honestly don't see much of a gripe here), you would still be able to get good relative data. I'm sure folks wouldn't mind sending you their amps if you could create a database of sorts with the data. If you catch me at the right time I'll send you an HD amp.


Just a suggestion. I'd be happy to do it myself but I've got enough to do as is. 

- Erin


Edit: This might help:
http://www.sengpielaudio.com/calculator-db-volt.htm


----------



## cvjoint

bikinpunk said:


> Why not build a measurement rig to measure the FR/THD/IMD of various amps? A basic setup could consist of a simple line level attenuator like the one linked below in line with the RCA's, rightmark, and... that's it.
> 
> Harrison Labs 12 dB RCA Line Level Attenuator Pair 266-244
> 
> Could run them in series for a 24dB attenuation. This should suffice for most amps intended for mid/tweeter (ie: no sub... high power situations). I didn't do the math, but feel free to see if that's enough attenuation. Most soundcard inputs accept up to about 1v in before issues arise.
> 
> 
> Even if it's not absolute (which, I honestly don't see much of a gripe here), you would still be able to get good relative data. I'm sure folks wouldn't mind sending you their amps if you could create a database of sorts with the data. If you catch me at the right time I'll send you an HD amp.
> 
> 
> Just a suggestion. I'd be happy to do it myself but I've got enough to do as is.
> 
> - Erin
> 
> 
> Edit: This might help:
> dB dBu dBFS dBV to volts conversion - calculator volt volts to dBu and dBV dB mW - convert dB volt relatioship relation convertor converter calculation online attenuation loss gain ratio reference audio engineering sound recording dBFS dBVU 0 dB audi


I'm fairly new at amplifier testing. At some point I may feel comfortable with some testing but I'm far from that point. Not to mention gradschool is taking it all out of me right now. Maybe when I have a job for some time and a family and need my hobbies to play a more important role. Besides, speaker testing is where it's all at. 

Do you plan to do the entire set of testing on the Illuminator or just Klippel?


----------



## cvjoint

It just dawned on me that I haven't yet looked at Tympany's LAT speakers yet. I spent some time researching them yesterday. It's a shame they don't make them anymore. 

Stole a picture from a member in case some have never seen one, it's a two motor multiple cones cylinder:









Here is some modeling on them. Dual LAT250s versus one Scan Speak Illuminator 7" with a 63hz high pass filter and quad LAT500s vs. triple Vifa Ne315s. The choices of LAT combinations is the most I can fit in the door and trunk baffle. That ends up being a 8.5" x 7" midbass and a 12"x 36" subwoofer.










I increased power until I reached xmax. Xmax is 3mm for the Lat 250, and 5.5mm for the LAT 500. 9.5mm for the Scan, and 12mm for the Vifas. Here I am assuming the Tympany ratings on the LAT are true, which as we know is usually overstated by manufacturers but sometime understated by the Danes. Maybe Erin will Klippel one, that would be a really interesting test. 

Power wise the LATs are far from rated power but the conventional drivers are 10-16w over the rating, which is negligible. 

The Q. is the same for the sub utilization but really high for the midbass one, in the .9 range and that's not so cool. 

*Conclusion*
The LAT combinations cannot achieve more SPL at a given distortion threshold. The advantages in increased surface area (160% more than the Scan, 30% more than the Vifa) are not enough to offset the linear motors in the conventional drivers. Overall, conventional technology ends up displacing more air linearly. That is the major drawback of the LAT technology, it still relies on very small speaker motors to move all that area. Sure you have 10 2.5" cones in the LAT250, 20 of them against one Scan Speak, but the motor is still that of a 2.5" speaker, and they simply can't move enough. The lack of success of the LAT is often rested on the lack of surface area, I think it's the motor that lacks. 

So then comes the tradeoff. Due to the push pull design, the LATs will not shake your car up, that means less distortion from panels rattling. In turn they will distort more themselves. And here is where the hammer hits the nail on the head, someone that can design a low rattle car can easily surpass the LATs with conventional drivers. 

Other benefits of conventional cones:
Better IMD
Better decay
Higher frequency response
Lots of choices 
Smaller footprint
Less weight

But can we really design a low rattle environment for high power vehicles? Have you listened to your midbass or subs by themselves lately?


----------



## BigRed

I have one if u wanna play with it George . The smaller one


----------



## t3sn4f2

Zaph has the 250 in his tidbits.


----------



## bassfromspace

I've actually got 6 that I forgot about. I was planning to do 3 per side for midbass.


----------



## cvjoint

BigRed said:


> I have one if u wanna play with it George . The smaller one


Sweet. I may take it for a while. I can just make a baffle and drop it in the sub box I test cabin gain with. I can do an SLS vs LAT comparison. 

I really could fit two per side. 3 would be ideal but oh well. How many LATs does it take till you get to the bottom of the ... .... 

I don't even know what output Zaph tests in tidbits. Is it anywhere on the site? Doesn't seem promising in singles, but the benefit comes with multiple units and high output. Where conventional speakers start rattling your door these should sound much cleaner.


----------



## cvjoint

New Wheels!


----------



## cvjoint

I've been thinking of ways to improve the pillar pods. Based on what the alchemist proofs showed it would be nice to obtain a wider bandwidth for the pillar mids. This should reduce group delay significantly. Other ways I can reduce group delay is to get speakers that have a really low impedance peak, a really low frequency impedance peak, and a very low Qts. Last method of improving the transient response would be to use a stiffer cone, and a smaller cone. 

*Enter the Seas Excel Magnesiums W12:*









These have one of the most rigid cones ever made. Unlike aluminum which is more commonly used, the magnesium seems move the breakup even further up, and it is generally better damped. The cone is smaller than the Faital. The impedance is lower in frequency and amplitude than any other 4" I've looked at so far. The group delay is also lower than any 4" speaker I've looked at. This is then, the best choice I could find for accurate transient response.

*Benefits:*
*best choice for maximizing transient response
*very good inductance performance
*Drawbacks:*
*lower output, and therefore I would think higher THD at high SPL
*breakup necessitates lower LP crossover

The goal was to achieve 110db output in the midrange. With the Faital I'm at over 115db per side. It's more than I need. I think the Seas will do well despite the output disadvantage. 

The lower LP xover is fine with me. I was going to reduce it anyway. Due to the CTC spacing and dispersion requirements I shouldn't be crossing 4.5" speakers over 3,000hz anyway. I still manage to get the crossover over the telephone range 300hz-3khz so I'm happy with that. 

*Design:*
I'm thinking of using the following crossovers: 125hz-3khz for the pillar mids. Then I would upgrade the 3/4" tweeter to the Scan Speak Illuminator to handle the low crossover point of 3,000hz. That will give me no comb filtering and omindirectional dispersion patterns. 

Since the Seas are not truncated I'm thinking of using a MTM setup instead of MMT like I have now and offset the tweeter to reduce diffraction, like this:










What do you all think?


----------



## fish

That's alot to take in in one post. 

One thing that stands out to me that I'm confident in responding to is the 125hz high-pass. Obviously you're losing output from the Faitality array, but are you concerned that 125hz is a bit low for your desired output? I know you modeled them, whatcha got? 

One more thing... can you explain how the offset tweeter in an MTM aids in diffraction?

Nice wheels BTW... simple & classy.


----------



## SSSnake

If you could fit the W16 I would say go for it. The W16s are beasts for their size 7mm Xmax (over double the W12s) and nearly double the Sd. Heck one of the W16s would likely keep up with two of the W12s. The only drawback is the diameter 5.7" vs 4.7"


----------



## ErinH

going to be interesting to see how you fit such a large driver in the pillar.


----------



## cvjoint

fish said:


> That's alot to take in in one post.
> 
> One thing that stands out to me that I'm confident in responding to is the 125hz high-pass. Obviously you're losing output from the Faitality array, but are you concerned that 125hz is a bit low for your desired output? I know you modeled them, whatcha got?
> 
> One more thing... can you explain how the offset tweeter in an MTM aids in diffraction?
> 
> Nice wheels BTW... simple & classy.


Well, the low end extension is the Seas's forte. If you model this thing it is imperatively flat down low. I hope it has a bit more xmax than the Faital, and while there isn't a Klippel on it the majority of small magnesium Excels kick ass in independent HD testing under 200hz. The resonant peak is 100hz lower in the Seas than the Faitals in the same enclosure. It's also 50hz lower than the Scan Speaks and the Dynaudio despite Dyn's low enclosure requirement. 

In practice I'm simply going to lower the xover point until the low end HD starts to peak at 110db. Wherever it stops that's where I'll choose it. Base on the modeling it will easily be lower than 200hz, 160hz for sure, 125hz might be a stretch. We'll see. It's almost a waste not to run it lower though, this is a midbass, where the Faital is more of a pure midrange. I just figured the Faital's top end extension is a waste since I need a low crosspoint due to the natural dispersion of a mid this large. 

Ah, forgot about the diffraction. Offset tweeters have asymetrical diffraction patterns about the edges of the pod. If they were symmetrical they would reinforce eachother making matters worse. That's my understanding. Additionally it gives me more room to fit the drivers as opposed to the baskets touching at the bottom and top in line. I wonder where the tweeter is best placed, near the side window or near the center of the car.



SSSnake said:


> If you could fit the W16 I would say go for it. The W16s are beasts for their size 7mm Xmax (over double the W12s) and nearly double the Sd. Heck one of the W16s would likely keep up with two of the W12s. The only drawback is the diameter 5.7" vs 4.7"


I love what Seas is doing with the 16 models. It's like they finally realized cone to basket ratio matters. What I would really like to see is a smaller basket on the W12. You have to remember that the larger the cone the lower the LP crossover has to be. One because it beams earlier and I want an omnidirectional patern, and two because the breakup moves down. That's not a good thing. The tweeter stresses more and I moved the crossover into the sensitive vocal region more. 

Besides, the larger xmax is not that useful. Either way it can't go down to 63hz to match the sub with authority. Then the two W12 handle more power, so there is less compression, and they also need less room together, at least that's my guess (two motors vs. one). In some cars this makes more sense, if you have lots of room but it's rather round or square. I can only work with a thin pillar.



bikinpunk said:


> going to be interesting to see how you fit such a large driver in the pillar.


I'm scared.


----------



## ErinH

yea. Short of cutting your dash, I can't imagine anyway you can integrate a 4-5" midrange on the dash/pillar without it causing some sight issues. I'm lucky with my civic because it has a pretty good sized pocket window to tuck the driver back in. If not for that, I'd have some issues with trying to make it fit. Honestly, I'd probably be using a 2-way... or some sort of array with whispers or the like. 

I'm crossing my fingers you don't wind up with a blob and I don't have to dog you for it. 

I kid. (kind of)


----------



## SSSnake

If you are worried about beaming either use a baffle in front of the cone with a smaller opening or use a diffraction ring.

The usable response (assuming a brick wall filter) only moves down 1000hz (from 5000hz to 4000hz).

I know, I know, it is all about trades and which ones you won't to make. Carry on...


----------



## cvjoint

I thought about truncating the Seas baskets. They can be taken down to 110mm at least, judging by predecessor units. I was going to trim the Exodus woofers but Excels...not sure I have the heart for it, or $. I'm pretty sure the value of these speakers would tank from $720 to a couple of hundred.

A diffraction ring you say. I'll look into this. From what I remember there are such things used in tweeters to get better dispersion. I think the design has to be very clever to not have strong side effects. 

I'm not set on this idea. I just thought it would be an interesting option. If the Faitals are the SPL/HD monsters the Seas would be the transient response leaders. 

Back to doing some more Linkwitz reading. 

Edit: neat idea on the dispersion modifier. Apparently it's as easy as having open cell foam with a hole in the middle over the speaker. 

http://www.tgpwebzine.com/?page_id=443


----------



## ErinH

There's discussion here on it as well if you search for a topic regarding Doug Winkler. 

There's a company who makes these rings for pro audio use which can be adapted to our drivers as well.


----------



## 24th-Alchemist

_cvjoint_ I'm glad you found that plot about class D amplifiers in the article in Car Audio Magazine about Alpine's PDX amps.

When I saw you were contemplating a move to class D my initial impulse was to say something, but I don't know a lot about amps, and I can neither test (due to cost) nor model (due to unknown specifics), so without being able to substantiate my thoughts I decided to remain mum.

But since you linked that plot I figured I'd offer some additional things to think about when contemplating class D:
A thread from CA mag closely related to the one you linked to is this: Alpine's New PDX and Its Technology - Amplifier Reviews - Car Audio and Electronics. If you go the the _"Sound and Measurement"_ section you'll see they talk about what seems to me to be the important development of Alpine's new "dual global feedback topology", where part of the amplifier feedback (FB) is connected directly to the speaker wire, in contrast with earlier class D implementations where a LC filter is between the amplifier FB and the speaker. The reason it matters, as is also mentioned in the link, is damping factor. Apparently people around here have convinced themselves that damping factor is irrelevant -- and perhaps it is for all reasonably well-designed class A/B amps -- but I'm not sure damping factor is automatically moot for class D, where the amplifier FB isn't always connected directly to the speaker wire. For someone like you who's looking to minimize every last once of THD, the added driver control afforded by amplifier FB might be important -- I really don't know but it might be worth looking into. And if anyone can chime in one way or another with claims that can be substantiated with measurements or simulations I for one would be interested to learn more.
In this link from _Elliot Sound_ there's some info about the benefits of active versus passive crossovers showing how amplifier FB control of drivers is reduced by passive crossovers -- the idea being that a LC filter on a class D amp might impose detrimental effects that are similar to a passive crossover.
Sir Siegfried also says the following here regarding passive crossovers, where, again, it might be worth determining whether the LC filter on a class D amp could impose similar issues (second to last sentence of particular importance): "_Crossovers may be implemented either as passive RLC networks, as active filters with operational amplifier circuits or with DSP engines and software. The only excuse for passive crossovers is their low cost. Their behavior changes with the signal level dependent dynamics of the drivers. They block the power amplifier from taking maximum control over the voice coil motion. They are a waste of time, if accuracy of reproduction is the goal."_
Lastly I'm skeptical even of class G because intuitively I don't see how the power rail can be drastically changed without there being some effect on the output of the output transistor. I'm not saying it can't be done I'm just saying there may be trade-offs and for someone with your goals it may behoove you to check these potential issues carefully.

I actually intended to post about group delay and speaker bandwidth but the above took too long so I'll plan to return later.


----------



## 60ndown

seriously? 

all the time and effort getting the pillars done and now your going to re do everything??


O.C.D is a disease,

Obsessive-compulsive disorder - PubMed Health


----------



## BigRed

It's Doug winker. Diffraction ring. Look up Gary Biggs installation. There are pics of it


----------



## cvjoint

24th-Alchemist said:


> _cvjoint_ I'm glad you found that plot about class D amplifiers in the article in Car Audio Magazine about Alpine's PDX amps.
> 
> When I saw you were contemplating a move to class D my initial impulse was to say something, but I don't know a lot about amps, and I can neither test (due to cost) nor model (due to unknown specifics), so without being able to substantiate my thoughts I decided to remain mum.
> 
> But since you linked that plot I figured I'd offer some additional things to think about when contemplating class D:
> A thread from CA mag closely related to the one you linked to is this: Alpine's New PDX and Its Technology - Amplifier Reviews - Car Audio and Electronics. If you go the the _"Sound and Measurement"_ section you'll see they talk about what seems to me to be the important development of Alpine's new "dual global feedback topology", where part of the amplifier feedback (FB) is connected directly to the speaker wire, in contrast with earlier class D implementations where a LC filter is between the amplifier FB and the speaker. The reason it matters, as is also mentioned in the link, is damping factor. Apparently people around here have convinced themselves that damping factor is irrelevant -- and perhaps it is for all reasonably well-designed class A/B amps -- but I'm not sure damping factor is automatically moot for class D, where the amplifier FB isn't always connected directly to the speaker wire. For someone like you who's looking to minimize every last once of THD, the added driver control afforded by amplifier FB might be important -- I really don't know but it might be worth looking into. And if anyone can chime in one way or another with claims that can be substantiated with measurements or simulations I for one would be interested to learn more.
> In this link from _Elliot Sound_ there's some info about the benefits of active versus passive crossovers showing how amplifier FB control of drivers is reduced by passive crossovers -- the idea being that a LC filter on a class D amp might impose detrimental effects that are similar to a passive crossover.
> Sir Siegfried also says the following here regarding passive crossovers, where, again, it might be worth determining whether the LC filter on a class D amp could impose similar issues (second to last sentence of particular importance): "_Crossovers may be implemented either as passive RLC networks, as active filters with operational amplifier circuits or with DSP engines and software. The only excuse for passive crossovers is their low cost. Their behavior changes with the signal level dependent dynamics of the drivers. They block the power amplifier from taking maximum control over the voice coil motion. They are a waste of time, if accuracy of reproduction is the goal."_
> Lastly I'm skeptical even of class G because intuitively I don't see how the power rail can be drastically changed without there being some effect on the output of the output transistor. I'm not saying it can't be done I'm just saying there may be trade-offs and for someone with your goals it may behoove you to check these potential issues carefully.
> 
> I actually intended to post about group delay and speaker bandwidth but the above took too long so I'll plan to return later.


I looked a bit at the effect of passive crossovers on damping factor. It's quite astonishing how low damping factor can get, even in the single digits! I concur with the belief that passive crossover are very prohibitive from this point of view, the damping factor getting under the safe threshold of 50. 

It's also quite clear that JL and Alpine offerings shine from this point of view. Their class D amps have very high damping factors and very good channel separation test results. 

In view of the PPI class D amplifiers that are half the cost the damping factor is lower at only 114, and channel separation at 32db. I've been trying to place these readings in context of audibility. Even at 2ohms it seems that the damping factor is over 50, out of the trouble range. No doubt this is not stellar but would it matter at all? I generally try to be sensible about improvements, I'm not quite sure the Alpine or Jl units would make a tangible difference. 

The other part that I'm going to look into is phase distortion. To my understanding the more expensive Class Ds move these further out of the hearing band. I would like to see if any tests quantify the difference. 


I'm thinking about drilling out the pillar pods a bit more and make removable baffles. This way I can swap speakers really quickly. The Faitals are still on their MDF temporary baffles. 

Looking forward to more input on the Seas idea and how to improve transient response or any other time domain behavior. Frankly I was hoping you would all shoot down the idea, the Seas are expensive as hell.


----------



## cvjoint

Or... should I do an MMMT!?

Enter my paint-job simulation:










*Benefits:*
SPL > 121db per side
THD < 1% @110db 200hz->
Ear level completely encapsulated by the line array length
Surface area, SD > 190 cm^2 (roughly 7.5" speaker)
Net efficiency of system = base efficiency + efficiency gain: 95.77db
Net sensitivity of system = base efficiency + efficiency gain + sensitivity gain: 100.5db
Where:
Efficiency gain = 10*log(Number Drivers)
Sensitivity gain = 10*log(8 ohms / nominal impedance of parallel combo)
source: HTGuide Forum - Calculating line array sensitivity
2.66ohm load -> more power, roughly 140W from one channel on the Clarion, 200w if I switch to PPI Phantom amps

*Dowsides:*
QTC raises from 1 to 1.15, ideal crosspoint would now be 250hz instead of 200hz to circumvent the impedance peak moving in. This shouldn't be a big deal once I move to the Scan Speak Illuminator midbass. That sucker can be crossed as high as 3,000hz 12db/oct. Even the SLS can do 250hz with a steep slope. 

Tweeter will have to be moved at the corner of the windshield taking a up a slight patch of viewing area. So far no viewing area has been sacrificed. The sun-visors might have to be modified, sigh.

By now I'm fairly convinced that the wall of sound and vast soundstage is merely a feature of the rectangular speaker patch creating a one of a kind dispersion pattern. I suspect this is the major attraction to electrostats, planars and the kind. 

I've also went back to old-school house mixes by Satoshi Tomiie and Damian Lazarus. I enjoy dynamics and low nonlinear distortion more than I thought. I'm giving more and more credit to those HT audiophiles building ceiling high line arrays.

Everyone should listen to this mix before dissing electronica:
http://www.amazon.co.uk/Renaissance-3d-Satoshi-Tomiie/dp/B000CRSEPY
Japan's all time best DJ.


----------



## eviling

holy cow. what is the objective of this system? just pure loud ? lol


----------



## cvjoint

eviling said:


> holy cow. what is the objective of this system? just pure loud ? lol


Say you could name all the aspects of sound reproduction. That would be high output, low nonlinear distortion, low phase distortion, small pathlength differences etc. Make a list. By each entry enter the relative weight of each aspect, based on how important it is to you or to the listening experience in general. 

The objective would be to create a system that when each aspect is weighed the sum total is as great as it can be. Simply put, I want it all. I know I can't get it all but I'm interested in making the most out of it. I use objective truths wherever I can replacing common beliefs to guide my choices.


----------



## 60ndown

id bet the right drivers in some good kick panels would actually perform better. 

or some horns?

your plds must be very different currently = not good


----------



## thehatedguy

Kicks in that car would be next to impossible to do...much less make sound good.


----------



## subwoofery

I know how 2-drivers-array works... What can you tell us about 3-drivers-array? 

Thanks, 
Kelvin


----------



## cvjoint

60ndown said:


> id bet the right drivers in some good kick panels would actually perform better.
> 
> or some horns?
> 
> your plds must be very different currently = not good


Sure. I would use some horns. In particular I would use a design that is only 42mm deep but loads down to under 200hz. 

The plds are not ideal, this is true. Now let me ask you something. Would you rather look at a standard definition TV in an empty room or a high definition TV when two kids are playing soccer right in the middle of your view?



subwoofery said:


> I know how 2-drivers-array works... What can you tell us about 3-drivers-array?
> 
> Thanks,
> Kelvin


Not much is different. Horizontally the dispersion will remain the same, basically omnidirectional up to and a bit over 3khz. Vertically the dispersion would be more like that of a 12" woofer, it will stop being omnidirectional at about 1.3 khz or so. Before it was 2.1khz the rule for a 8" woofer. The other benefits of line arrays are amplified, lower distortion and higher output. 

In my car it just means the array engulfs the ear level much better. It will sit 3" or so taller so even the tallest people will have omnidirectional sound throughout. Basically as long as you can see over the dash but you are not tall enough to have to put the top down to fit your head, the array will span your ear level. There should be fewer reflections off the soft top mechanism and dash to boot.


----------



## cvjoint

I've been playing around with the 3x Faital line array against the Audax 4" carbon fiber speakers as well as the Scan Speak 10f. The Audax and Scans certainly achieve a lower QTC in my pillars and certainly have less group delay, by like 1.5ms. The funny thing is, if I EQ. away a lot of the low end of the Faitals the group delay drops even below that of the others. Then there is so much more SPL on the Faital I can afford to do this to no end. The excursion is also much lower for any given output. 

In fact the higpass crossover contributes 7 times more group delay after equalization. It seems that the crossover is far more important than a smalish box or the speaker you choose. 

The more I look at it the more I like the Faitals. Faital gave the car audio world what Chevy gave motoring, a triumph in packaging. Chevy's LS motors are the default choice for any engine swapper or kit car builder, they just pack more power per square inch than any other. The way Faital's Pro speakers mount the surround over the flange, gives them an easy lead over the competition. With more surface area/basket diameter it manages to do things many speakers can't touch.

I would have to buy two more speakers very soon from the old stock, Faital seemed to have changed the flange design on the new models:









The new one is easier to surface mount. The old one is easier to flush mount. I was planning to flush mount so the old design works better.


----------



## 24th-Alchemist

Regarding class D amps I think there is a lot to think about. One thing I wonder about is the degree to which amplifier tests strain amplifier capabilities. Presumably the tests are designed to demonstrate strengths while minimizing the appearance of weaknesses. Take for example bandwidth. Very broadly speaking -- similar to how more bandwidth improves transient response for a speaker -- more bandwidth in a feedback (FB) system improves control (transient response). I run a modest class A/B amp in a Rockford P450.4 on my mids & tweets and it's bandwidth is listed at +/-3 dB 20 Hz to 200 kHz (specifications PDF here). I doubt few if any higher-end class D amps have the same bandwidth -- but does it matter? I don't know. I suspect though that a speaker, especially one in a moving car that is subjected to various vibrations, is a lot more complicated of a load for an amp to control than the loads used to ascertain distortion specifications. Intuitively I like the idea of incorporating feedback directly from the speaker wire as is apparently done with the second generation Alpine class D full-range amps, because I don't see how an output inductor can be low impedance up to 20 kHz but still have enough impedance to adequately filter out amplifier switching that's occurring at, what, the low to mid hundreds of kHz? Are there measurable consequences of class D FB? Probably. Are there important sonic consequences? I don't know -- but it wouldn't seem unreasonable to me if manufactures sacrificed some fidelity for a smaller chassis and more power, which most customers appear to value. Presumably there were class D versus A/B discussions with the first full-range Alpine PDX amps and probably there were people who insisted the class D was just as good as class A/B, but the car audio magazine article about the second generation class D amps implies that the first iteration wasn't "perfect", although this probably wasn't discussed much initially. So now are the second generation full-range class D's just as good as class A/B's? It would be interesting to have some frank input from an engineer who designs and tests these types of amps.



> Looking forward to more input on the Seas idea and how to improve transient response or any other time domain behavior. Frankly I was hoping you would all shoot down the idea, the Seas are expensive as hell.


Here's one shot at shooting things down: I think that the linear parts of the transient response that you can control will will be dominated by the crossover, not the speaker characteristics. The idea can be illustrated from the plot below which is a copy of the last plot I posted earlier on this thread.










The plot shows the modeled transient responses of three different speaker systems to a unit amplitude 0.5 ms pulse.

The black trace is the response of the best case system, which is a model of a simplified "wide open" driver with no crossover, where the relevant driver characteristics are _Q=.7_, _fc=80 Hz_ (12 dB/oct highpass) and _Le_ such that there is a 2.5 kHz 6 dB/oct lowpass characteristic. Broadly speaking the lowpass (LP) characteristic slows the initial rise of the response and the highpass (HP) portion is responsible for the early drop prior to 0.5 ms and the slow resonance back to baseline after 0.5 ms. There is also some phase distortion.

The blue trace is the summed acoustic response if the driver described above is used as both a midbass and a midrange in a configuration where the drivers are crossed over at 250 Hz, 4th-order Linkwitz-Riley.

Comparing the black and blue traces, the blue is significantly different but the drivers in the models are identical. Also recall that the frequency magnitude response of the summed acoustical response of the Linkwitz-Riley crossover is flat so the frequency magnitude (not shown) for the black and blue traces are _identical_. The difference is due solely to the phase distortion of the crossover.

Lastly, the green trace is the modeled response when the midbass has an _Le_ such that it starts to roll off at 300 Hz instead of 2.5 kHz. This is a major change in the midbass driver attributes that has a negligible effect on frequency magnitude in the midbass passband and a moderate effect on passband phase. There is little difference between the blue and green, illustrating again that the driver characteristics are not the dominating factor here. The crossover is.

I also listened to these waveforms and I could hear a difference between black and blue (crossover yes/no) but not blue and green (driver changes). In other words I could hear the effects of the crossover but not the effects of major changes in modeled driver attributes. (Specifically, _Le_ roll-off well outside the crossover [midbass for blue trace] and _Le_ roll-off at the crossover [midbass for green trace]).

If the discussion is about driver non-linearities, as was the case earlier in the thread, then the speaker is the dominating factor because an actively implemented crossover is a purely linear operation. If however the discussion is overall transient response, then I think it's fair to say that with any driver that is of reasonable quality and not overdriven, the crossover, and in particular its phase distortion contribution, is the dominating factor.

One last thing to note however is that at the HP side of a crossover the electromechanical properties of a driver can contribute somewhat to the crossover transient response. I think this is especially true for the crossover between midbasss and sub and could also be important for some midranges at their cross with the midbass (depending on driver and crossover frequency). There is a lot of info on the Linkwitz site about crossovers and he talks about integrating the elctromechanical attributes of drivers into the crossover to get a desired acoustical, as opposed to electronic, response. For example, a LR-4 high-pass response at _f0_ is achieved by cascading two 12 dB/oct Butterworth highpasses at _f0_. One way to do this is to enclose a driver so it has a _Q=.707_ (Butterworth) and _fc = f0_. Then cascading a single electronic butterworth HP at _f0_ at 12 db/oct with the enclosed driver achieves an acoustical LR-4 at _f0_. If the mechanical characteristics of the driver are such that _Q_ and _fc_ cannot be manipulated to match the desired crossover _f0_ then a Linkwitz compensator ("Linkwitz transformer") can be used -- but not another cascaded Butterworth HP. When people for example use an electronic LR-4 crossover in a HP scenario for midbass at the sub crossover they are probably not achieving an acoustic LR-4 response at the midbass because in such a case the electromechanical characteristics of the midbass will often contribute significantly to the overall acoustic response. (A similar, albeit perhaps not quite as strong of an effect, could also be important to consider for the midrange HP). The plot I posted above however shows an example where the _Le_ attributes don't have a huge effect on the low-pass side of the crossover.

Even when the driver characteristics do contribute somewhat to linear transient response -- for example on the HP side of a bandpass crossover -- they are only half of the contribution for a LR-4 crossover and they're less than half if the HP is an electronic LR-4. On the LP side the crossover seems to often dominate the transient response.


----------



## 24th-Alchemist

> It seems that the crossover is far more important than a smalish box or the speaker you choose.


I wish I would have seen this prior to composing my previous post. Bad timing.


----------



## subwoofery

24th-Alchemist said:


> I wish I would have seen this prior to composing my previous post. Bad timing.


No... Actually it was really helpful. I've noticed in WinISD that group delay was affected by Xover slopes. 
From then, I managed to change a few slopes in my system for the better and have been using 6dB and 12dB more often than 24dB. 

Kelvin


----------



## 60ndown

thehatedguy said:


> Kicks in that car would be next to impossible to do...much less make sound good.


care to elaborate a little for me?

the driver and passenger have room for their feet, and kicks have been getting great sound in a lot of cars from a long time.

why not this one?


----------



## 60ndown

cvjoint said:


> Would you rather look at a standard definition TV in an empty room or a high definition TV when two kids are playing soccer right in the middle of your view?


id go standard with no kids, but how does this analogy apply to your speaker placement?


----------



## thehatedguy

A S2000 is TINY on the inside. Couple the tiny interior with a large transmission tunnel, it wouldn't make for really great sound.


----------



## cvjoint

24th-Alchemist said:


> Regarding class D amps I think there is a lot to think about. One thing I wonder about is the degree to which amplifier tests strain amplifier capabilities. Presumably the tests are designed to demonstrate strengths while minimizing the appearance of weaknesses. Take for example bandwidth. Very broadly speaking -- similar to how more bandwidth improves transient response for a speaker -- more bandwidth in a feedback (FB) system improves control (transient response). I run a modest class A/B amp in a Rockford P450.4 on my mids & tweets and it's bandwidth is listed at +/-3 dB 20 Hz to 200 kHz (specifications PDF here). I doubt few if any higher-end class D amps have the same bandwidth -- but does it matter? I don't know. I suspect though that a speaker, especially one in a moving car that is subjected to various vibrations, is a lot more complicated of a load for an amp to control than the loads used to ascertain distortion specifications. Intuitively I like the idea of incorporating feedback directly from the speaker wire as is apparently done with the second generation Alpine class D full-range amps, because I don't see how an output inductor can be low impedance up to 20 kHz but still have enough impedance to adequately filter out amplifier switching that's occurring at, what, the low to mid hundreds of kHz? Are there measurable consequences of class D FB? Probably. Are there important sonic consequences? I don't know -- but it wouldn't seem unreasonable to me if manufactures sacrificed some fidelity for a smaller chassis and more power, which most customers appear to value. Presumably there were class D versus A/B discussions with the first full-range Alpine PDX amps and probably there were people who insisted the class D was just as good as class A/B, but the car audio magazine article about the second generation class D amps implies that the first iteration wasn't "perfect", although this probably wasn't discussed much initially. So now are the second generation full-range class D's just as good as class A/B's? It would be interesting to have some frank input from an engineer who designs and tests these types of amps.
> 
> 
> 
> Here's one shot at shooting things down: I think that the linear parts of the transient response that you can control will will be dominated by the crossover, not the speaker characteristics. The idea can be illustrated from the plot below which is a copy of the last plot I posted earlier on this thread.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> The plot shows the modeled transient responses of three different speaker systems to a unit amplitude 0.5 ms pulse.
> 
> The black trace is the response of the best case system, which is a model of a simplified "wide open" driver with no crossover, where the relevant driver characteristics are _Q=.7_, _fc=80 Hz_ (12 dB/oct highpass) and _Le_ such that there is a 2.5 kHz 6 dB/oct lowpass characteristic. Broadly speaking the lowpass (LP) characteristic slows the initial rise of the response and the highpass (HP) portion is responsible for the early drop prior to 0.5 ms and the slow resonance back to baseline after 0.5 ms. There is also some phase distortion.
> 
> The blue trace is the summed acoustic response if the driver described above is used as both a midbass and a midrange in a configuration where the drivers are crossed over at 250 Hz, 4th-order Linkwitz-Riley.
> 
> Comparing the black and blue traces, the blue is significantly different but the drivers in the models are identical. Also recall that the frequency magnitude response of the summed acoustical response of the Linkwitz-Riley crossover is flat so the frequency magnitude (not shown) for the black and blue traces are _identical_. The difference is due solely to the phase distortion of the crossover.
> 
> Lastly, the green trace is the modeled response when the midbass has an _Le_ such that it starts to roll off at 300 Hz instead of 2.5 kHz. This is a major change in the midbass driver attributes that has a negligible effect on frequency magnitude in the midbass passband and a moderate effect on passband phase. There is little difference between the blue and green, illustrating again that the driver characteristics are not the dominating factor here. The crossover is.
> 
> I also listened to these waveforms and I could hear a difference between black and blue (crossover yes/no) but not blue and green (driver changes). In other words I could hear the effects of the crossover but not the effects of major changes in modeled driver attributes. (Specifically, _Le_ roll-off well outside the crossover [midbass for blue trace] and _Le_ roll-off at the crossover [midbass for green trace]).
> 
> If the discussion is about driver non-linearities, as was the case earlier in the thread, then the speaker is the dominating factor because an actively implemented crossover is a purely linear operation. If however the discussion is overall transient response, then I think it's fair to say that with any driver that is of reasonable quality and not overdriven, the crossover, and in particular its phase distortion contribution, is the dominating factor.
> 
> One last thing to note however is that at the HP side of a crossover the electromechanical properties of a driver can contribute somewhat to the crossover transient response. I think this is especially true for the crossover between midbasss and sub and could also be important for some midranges at their cross with the midbass (depending on driver and crossover frequency). There is a lot of info on the Linkwitz site about crossovers and he talks about integrating the elctromechanical attributes of drivers into the crossover to get a desired acoustical, as opposed to electronic, response. For example, a LR-4 high-pass response at _f0_ is achieved by cascading two 12 dB/oct Butterworth highpasses at _f0_. One way to do this is to enclose a driver so it has a _Q=.707_ (Butterworth) and _fc = f0_. Then cascading a single electronic butterworth HP at _f0_ at 12 db/oct with the enclosed driver achieves an acoustical LR-4 at _f0_. If the mechanical characteristics of the driver are such that _Q_ and _fc_ cannot be manipulated to match the desired crossover _f0_ then a Linkwitz compensator ("Linkwitz transformer") can be used -- but not another cascaded Butterworth HP. When people for example use an electronic LR-4 crossover in a HP scenario for midbass at the sub crossover they are probably not achieving an acoustic LR-4 response at the midbass because in such a case the electromechanical characteristics of the midbass will often contribute significantly to the overall acoustic response. (A similar, albeit perhaps not quite as strong of an effect, could also be important to consider for the midrange HP). The plot I posted above however shows an example where the _Le_ attributes don't have a huge effect on the low-pass side of the crossover.
> 
> Even when the driver characteristics do contribute somewhat to linear transient response -- for example on the HP side of a bandpass crossover -- they are only half of the contribution for a LR-4 crossover and they're less than half if the HP is an electronic LR-4. On the LP side the crossover seems to often dominate the transient response.


On Bandwidth: I would guess the tweeter has an overwhelming effect on the upper most low pass. Just look at how many people use a 1" tweeter versus a 3/4". The difference between dome sizes, even between 25mm and 27mm is bound to overwhelm the amplifier rolloff by several times. The difference between a Class D that only works up to 40khz and one that works up to 100khz amounts to possibly hundredths of a ms in group delay. Does this problem exist? Surely. Does it matter? I don't think so. How sharp of a knife do you need to cut butter?

Partial Information: there is an obvious bias in amplifier reviews. This is clear to anybody watching the class D market penetration occur. Class D shortcomings only appear in reviews when some design finally addresses them. I think I know what the culprit is. Reviewers rely on manufacturers to consciously ship them an amplifier for testing. Even VC magazine has a short snippet at the end where producers are urged to send speaker samples for testing. They rely not only on the manufacturer for the test bench product but also for the green light. This is a clear case of sample selection bias and well flat out bias. Like any market you just have to trace down where the money and decision making is to get the right view.

On the other hand I'm thankful that magazines even touch a test bench. The average car audio enthusiast is happy to be ignorant of any process that seeks to "prove" but merely seeks confirmation of its own decisions. This hobby has a large support in overgrown boys feeding big egos. It's easy to see why none of the bad stuff shows up, the reader can easily fudge the overall review in his own biased understanding. If some shortcoming is nonaudible or irrelevant can you trust that your readers see it? Isn't it more likely they'll walk out with the message class D is not sq? 

Class D originals: lower damping factor, restricted bandwidth, increased interaction with car electronics signals, impedance dependent frequency response. I'm willing to to go with the >50 rule for damping factor. Keeping in mind how it varies by impedance I would think as long as the 50 mark is hit all is ok. Based on your simulations the bandwidth doesn't trouble me as it will have a very negligible impact on transient response. As far as the frequency response, it should be fine with most 4 ohm tweeters as it is optimized as such. For those people that run 8 ohm tweeters I'd be careful. From the list of downsides the only one that worries me is the interaction with electronics. I've had class D amplifiers do really weird things before. There are also members claiming their radio antenas don't work anymore and such. This is a risk indeed. 

On the other hand the class D benefits are very tangible. A more stable voltage is a clear advantage. The reduced footprint can be returned to storage use or would allow for a larger speaker box. If the footprint is kept the same then there is a lower chance of overheating or getting noise pollution from a loud fan. On this topic I always wondered if the tests would look different in a hot amplifier. 

At the end of the day my basic belief is that I've seen enough to say Class D amps may sound the same beyond a reasonable doubt. The benefits are more tangible than the downsides. It's not like class AB is the golden standard, it has to go through a cost benefit analysis all the same. 


On the simulations: I am sold on the impact of HP and LP filters as well as LE simulated as a LP filter. What is your basic belief on the importance of QTC, FC, and EQ. in regards to group delay? From my simulations what a tight box brings in, in terms of increased delay, EQ.ing away can give back. As long as there is no thermal concern I would think sticking a big speaker in a small box + EQ. is a wiser choice than a small speaker in a rightful small box and no EQ. If we all aim for low Q alignments we will generally give up larger speakers, but is it worth it if EQ. gives back what is lost in terms of transient response?

On the application: this is imo the best part about your simulations, being able to apply them somehow. If the crossover is the dominating factor for transient response we should seek to work more on this. If a wider bandwidth is the driving force this has big implications for the driver and design that should be used. For example, planars would be a poor choice because they require really tame HP filters. Metal cones would be a poor choice since they require really tame LP filters to circumvent cone breakup. This is quite the opposite of what the industry producing metal cones and planars/ribbons claim!! I would think... a line array of paper cones with very linear motors is the way to go. The paper cones seem to have well behaved breakups. The line array allows for small drivers to produce big sound, moving the LP filter higher without giving up dynamics. The linear motors and off course multiple use of drivers allows for a lower HP filter. Am I right in drawing these conclusions?


----------



## cvjoint

60ndown said:


> id go standard with no kids, but how does this analogy apply to your speaker placement?


Place the HD TV on the floor and you got yourself an analogy to kick speakers. I merely replaced one sensory input, audio, with video. Kicks have large swings in frequency response, you basically have an active element (your legs) creating ever changing absorbtion and deflection patterns. It's like if distortion behaviour could have a changing nature, a third axis if you may that is what your legs do. There is nothing more annoying to me that having my vision or sound blocked, absorbed and deflected in random patterns. 

Would I do kicks again? Sure. If I had no legs and no passenger seat, or if I listened to my car parked but had my legs in just one standard position.


----------



## cvjoint

Santa should improve his analyst group. I haven't been that good this year:





































I have the Scan Speak Illuminator 7" playing off a crappy 40w amp full range free air in my room. Wow. Wow. Wow.


----------



## denetnz

cvjoint said:


> Santa should improve his analyst group. I haven't been that good this year:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I have the Scan Speak Illuminator 7" playing off a crappy 40w amp full range free air in my room. Wow. Wow. Wow.


Awesome! You've got my blood pumping now! 

I just had my Illuminator 7"s put in today, but currently my the rest of my new system (P99, F6, M12, L1 Pro R2) is still in boxes and my old gear is stewn around the car. I'm trying *really* hard to resist the urge to do an all night install... I hope to get them fired up tomorrow...


----------



## cvjoint

denetnz said:


> Awesome! You've got my blood pumping now!
> 
> I just had my Illuminator 7"s put in today, but currently my the rest of my new system (P99, F6, M12, L1 Pro R2) is still in boxes and my old gear is stewn around the car. I'm trying *really* hard to resist the urge to do an all night install... I hope to get them fired up tomorrow...


Makes the rest of the speakers out there look like dinosaurs doesn't it?  I'll put it up against my existing set of SLS midbasses. Well there is enough info in this thread to compare it to the B&C 7". I have no doubts it's going to be a better bass driver than the SLS but is it a better midrange driver than the B&C at the same time?? 

Looking at the Illuminator is like glancing at the fruit of the labor of an idealist. It's like some savant's mind was free to delve in the complete bag of "what if's.". He comes out of his lab weeks later holding this jewel in the palm of his hand. This is the marriage of passion and genius materialized.


----------



## 60ndown

with all the wind (80+db) rushing past and over the roof (right next to the drivers) or even with the roof down, do you honestly believe you will hear any of the subtle differences between these set ups at 50 mph+, 

or do you only care about parked?

ive used $5 drivers and expensive ones, the differences after eq are minimal.


even the way those scan speaks are drilled for mounting makes no sense (other then buy me gimmik) evenly spaced holes all the way around makes much better sense, 

to me?


----------



## ErinH

I agree, the spacing of the holes seems odd, but the scanspeak illuminator line performs better than any other drivers I've tested. They are probably the best engineered transducers out there when used in their intended range. Given that, I'd venture to say the engineers at Scan know exactly what they're doing with that hole pattern and I seriously doubt it's a gimmick (seriously, if you think scan is going for gimmick then you know nothing about their product at all).

Aditionally, the illuminator has more linear throw than any woofers it's size that I've seen. Those are the kind of differences you're paying for. And, I think you would agree that while subtle differences may not be audible at highway speeds, the more excursion you can get without distortion, the better it is for those exact situations.


----------



## cvjoint

60ndown said:


> with all the wind (80+db) rushing past and over the roof (right next to the drivers) or even with the roof down, do you honestly believe you will hear any of the subtle differences between these set ups at 50 mph+,
> 
> Let's say a live orchestra is the gold standard. Going to any recording at all is going to significantly diminish the impact of the performance. Even the best home audio designs come short by a lot. Then you move into a car where there are massive space and noise constraints. Somehow there is an entire forum full of people who don't think these restrictions completely ruin the potential - DIYMA. In the last step you go from 45db of bk noise to 70db or so on average. Somehow though, you think that the difference between 70db and 85db is enough to make this effort futile?
> 
> I've taken this car to 140mph. Was I trying to tell the difference between crossover points as I was clamping on to the wheel? No. But I often find myself in 65mph traffic on a hot day. I turn the A/C on and the music up. It makes long boring and traffiky drives quite pleasant. There are also very few things in life better than cruising in a California canyon top down with your favorite tune on. I wouldn't trade that for a luxurious hardtop with low bk noise.
> 
> or do you only care about parked?
> 
> This is obviously just a jab.
> 
> ive used $5 drivers and expensive ones, the differences after eq are minimal.
> 
> If you've read this far and think my latest purchase are yet another step in spending more to get a hair more you couldn't be more wrong. You should see for one that I replaced the $110 B&C with a SLS that was $45. What could possibly that mean?
> 
> Maybe the $5 driver cost $2 to make. Maybe the expensive drivers you bought cost $2 to make. Maybe they were the same driver! Maybe the production process has different cost functions. The expensive driver may be handmade but equally as good as the conveyor belt cheap driver.
> 
> In any case you don't see me arguing that it's you who can't hear a difference, that your hearing is bellow par. Why? Because I don't want to issue any jabs.
> 
> even the way those scan speaks are drilled for mounting makes no sense (other then buy me gimmik) evenly spaced holes all the way around makes much better sense,
> 
> I think it does make sense. For example, you could have said the Scan Speak way of drilling holes is as good as random. What you did say is that *evenly* spaced holes are better. Why did you say even and not random? Because *even* is better. Well, maybe drilling holes by the basket spoke is better than even. Yes, the screw holes match the basket form. Why would that be? If you spend some time at the track watching people race on a circuit you will see more often than you think wheels coming back bent. The majority of bends occur on the barrel, between spokes. That is the weaker spot of the wheel, much as in the same way the speaker basket is weaker around the basket rim where the frame is not supporting it. Also notice that the Scan's are aluminum and that this metal does not bounce back after deforming. You bend it, it stays bent.
> 
> Now think about the way a speaker is clamped on. You have screws forever exerting a force on the aluminum basket. In a car you also have large swings in temperature, making the metal soft and then hardened all the while the screws are still exerting that same one way force. You may even have a irregular shaped baffle, that too will exert a force trying to bend the basket over time.
> 
> Do I think it will make a difference? Maybe. I'm not saying it's a major design feature. Do I think it's a gimmik? No.
> 
> 
> 
> to me?


First tests should be up today.


----------



## cvjoint

bikinpunk said:


> I agree, the spacing of the holes seems odd, but the scanspeak illuminator line performs better than any other drivers I've tested. They are probably the best engineered transducers out there when used in their intended range. Given that, I'd venture to say the engineers at Scan know exactly what they're doing with that hole pattern and I seriously doubt it's a gimmick (seriously, if you think scan is going for gimmick then you know nothing about their product at all).
> 
> Aditionally, the illuminator has more linear throw than any woofers it's size that I've seen. Those are the kind of differences you're paying for. And, I think you would agree that while subtle differences may not be audible at highway speeds, the more excursion you can get without distortion, the better it is for those exact situations.


Let me put your words into perspective with some little anecdotes:

*The Illuminator tweeter is rated at 4x the xmax of the Vifa. 4x more air displaced. Even if that only gives you 1 khz lower crossover, that is the difference between having to use a small 4" midrange over being able to use a 6.5" to cross over. You can also think about cone materials, with the Vifa you would need paper whereas with the Scan you can cross to a metal cone or adamantium. 

*Historically Scan Speak has been either rating drivers on par with Klippel tests or underrating, especially the Illuminator and Revelator lines. The Vifa NE are generally overrated by this metric, with the exception of the 12" sub. 

*The Scan Speak midbass models to about 4db more linear output. If we can hear differences of 1db, this change will be huge! 

*The Scan Speak midbass also has unusually low distortion up to 6khz, whereas the SLS gets wild at only 400hz. That means you can cross the Scan Speak almost 4 octaves higher!

*You can get 4db more linear bass output while crossing 4 octaves higher. This is very different than having these benefits split over two speakers. The Scan is then a UFC champion and a scholar.


----------



## circa40

welcome to the club


----------



## ErinH

We need our own club.


----------



## cvjoint

We can go around kicking ass and taking names. 

Vin, these are quite different than your 5s. The clove pattern is indeed only pocking on the outside. It's stamped on this one, the back has indents. 

The surround is not quite as tall as yours either. This looks like a standard roll but if you look closely it is not. There is indeed asymmetry in the surround, it's just barely noticeable. The stiffness of the rubber also varies. If I press the outside the rubber is more rigid, but it's noticeable softer on the inside. 

The cone is highly concave as well. This is probably the single most important attribute for the breakup. No wonder it's moved so far up. The depth of the Illuminator is as much about stroke as it is about cone geometry. This a precision piece, polished over many iterations.


----------



## circa40

cvjoint said:


> We can go around kicking ass and taking names.
> 
> Vin, these are quite different than your 5s. The clove pattern is indeed only pocking on the outside. It's stamped on this one, the back has indents.
> 
> The surround is not quite as tall as yours either. This looks like a standard roll but if you look closely it is not. There is indeed asymmetry in the surround, it's just barely noticeable. The stiffness of the rubber also varies. If I press the outside the rubber is more rigid, but it's noticeable softer on the inside.
> 
> The cone is highly concave as well. This is probably the single most important attribute for the breakup. No wonder it's moved so far up. The depth of the Illuminator is as much about stroke as it is about cone geometry. This a precision piece, polished over many iterations.


Oh, I didnt notice you got the metal cones. Now that I look closer at your picture, yours looks like it has a fat a$$ surround vs. my tall surround

I really hope you can get them to fit...or else you'll to get a Fit :laugh:


----------



## 60ndown

cvjoint said:


> "There are also very few things in life better than cruising in a California canyon top down with your favorite tune on. I wouldn't trade that for a luxurious hardtop with low bk noise. "




i disagree, 

there are MANY thing way better (you ever had a great bj?). *and* if you compare the amount of time we can actually spend driving through canyons with the top down, compared to the amount of time we spend going to and from our daily lives, the luxurious hardtop with low road noise makes much more sense, and yields much more pleasure...

imoymmv.


----------



## cvjoint

*Results for Scan Speak Illuminator 3/4" soft dome vs. Vifa NE 3/4" soft dome*

This is a classic battle. The Vifa driver is mechanically very similar to the Scan Speak, both are aluminum chambered tweeters, both have copper in the motor, both have damping behind the dome at some point, both have massive voicecoils, both have vented formers and motors. They are also made in the same Danish tradition of engineering might. The Vifa however is $30 whereas the Scan is $130. The Vifa uses overseas labor to cut down on costs, the Scan uses in house assembly. 

It seems tough to find any differences but if you look closely there are some. The Scan voicecoil is wound keeping in mind of the venting and it doesn't cover the holes in former. There is more damping material everywhere. The chamber is much larger and shaped differently. The faceplate has a built in waveguide to boost low frequencies. The grille is metal and much stronger than the Vifa. In fact the Vifas are ridiculously easy to bend and many have bent on their way to their owners. 

So do any of these little improvements end up improving the performance of the tweeter noticeably? 

*The contenders:
*



























*Note:* Erin did the hard work of soldering some wire ends because the terminals break really easy on these guys. The Scan does not come out of the factory with electrical tape and wires but I appreciate the way mine did. The Vifas suffer from the same ease of breaking.

*Performance Tests*

For these series of tests I taped the mic solid to my ebrake. This way it was a little over two feet away from the tweeter. No doubt this tests my car's environment as well. The relative difference is what is important, and with a solid mic position I figured you guys would have a better chance seeing a proper CSD and HD comparison. As for FR I find either one fixed position or lots of averaged curves work just as well but I can't average CSDs or HDs and with a tweeter a slight movement will matter so fixed it was. I used a 24db 2.5khz HP filter. This is my preferred method as it is more realistic imo and works for many other crossovers above that. 

*Frequency Response
*









On some sites the Vifa is rated 90db while the Scan is rated 88.5db. In the white sheets they are both rated about the same and that's what you see here as well, at least if their REs are about equal. Less than 2db difference between the two throughout. In this test they look nearly identical to me. So far, no reason to spend Scan money. 
*CSD*

Scan:









Vifa:









Lesson? You can't compare CSDs in car. If there are any differences they are overwhelmed by the reflections. 

Next, the bread and butter, HD tests.


----------



## cvjoint

*Scan HD @ 105db vol 54 on the head:*










*Vifa HD @105 vol 57 on the head:*









These are probably the best tests to look at, the most power so the best signal to noise in the measurements. You will note that the Scan is tested at a lower headunit setting. If I put both at 57 the Scan had much higher fundamental output. Basically, either because it has less power compression or because the motor is more linear (probably both) it puts out more clean SPL for the same power input. To be fair I backed up the knob so that they are tested at roughly the same mic perceived output. 

Scan HD @ 100db vol 52 on the head









Vifa HD @ 100db vol 52 on the head









Scan HD @95db vol 47 on the head








Vifa HD @95db vol 47 on the head









*Conclusion:*
This is basically where the Scan money starts to pay off. At very low levels they may be comparable distortion wise, but you can see even in the lowest output test the third order distortion is a bit higher in the Vifa. This difference is even more obvious as more power is applied, the third order rising higher and higher whereas it's not picking up at all in the Scan. The second order distortion starts surpasing that of the Scan at high output as well. In the highest output test all orders of distortion are higher in the Vifa and there is noticeable output lost on top of that. No doubt at high output the Scan keeps it's cool much better.

Quantitatively the differences are small, maybe 1% difference @105db. Will you hear it? I don't know. But the Scan does have a better distortion profile and higher output stability.


----------



## 60ndown

4x the cost and very similar performance.


----------



## cvjoint

To put things into perspective, I spent 350 Danish Kroner on two boxers in Denmark this summer. That comes out to $65 or so. They are supposed to last forever though. 

I just noticed that there is a but load of distortion bellow the crossover. Look at 2khz in the 105db plot. The Vifa is at 4.5%, while the Scan is at 1.5%. We are also quite sensitive to distortion at 2khz. That probably explains why the Scan sounds significantly better to my ears.


----------



## t3sn4f2

cvjoint said:


> To put things into perspective, I spent 350 Danish Kroner on two boxers in Denmark this summer. That comes out to $65 or so. They are supposed to last forever though.
> 
> I just noticed that there is a but load of distortion bellow the crossover. Look at 2khz in the 105db plot. The Vifa is at 4.5%, while the Scan is at 1.5%. We are also quite sensitive to distortion at 2khz. That probably explains why the Scan sounds significantly better to my ears.


And that extra 2dB in the 2-2.5kHz range must useful.


----------



## sqnut

Congrats on the scan mid. Looks like it needs some serious mounting depth. I run those Scan tweets and they are great and yes the terminals are really flimsy for $ 250 tweeters



t3sn4f2 said:


> And that extra 2dB in the 2-2.5kHz range must useful.


I think the lower distortion on the Scans counts for more than the extra db's.


----------



## cvjoint

Two sides of the same coin. The better driver can achieve more SPL for a given distortion target. Or the better driver can achieve lower THD for a given SPL. 

Since this forum is reportedly esque, SPL is often frowned upon. Generally the two go hand in hand.


----------



## sqnut

cvjoint said:


> Two sides of the same coin. The better driver can achieve more SPL for a given distortion target. Or the better driver can achieve lower THD for a given SPL.
> 
> Since this forum is reportedly esque, SPL is often frowned upon. Generally the two go hand in hand.


True. How about a slightly subjective review on 'how it sounds', with the scan mid and tweets?


----------



## cvjoint

sqnut said:


> True. How about a slightly subjective review on 'how it sounds', with the scan mid and tweets?


I can tell you the Scan tweeter does sound better than the Vifa. I've been trying to tease out good quality information by testing drivers against each other in similar environments using precise tools and techniques. 

The Scan midbass does not fit in my car in the same install, I'll have to change the baffle design significantly, it won't be as comparable. I'm trying to think of a way to have it and the SLS in a similar test situation. 

I'll leave subjective evaluation to somebody else. There is no shortage of those. Besides, I think I may be winning some brownie points with some readers with the testing and I'd hate to route them to some mismanaged information in the end. Wouldn't it be a shame if they skipped the tests and read the ramblings as gospel? That's what I'm trying to avoid. I want people to see the beauty of "proving" something. The tests are the magnum opus.


----------



## ecbmxer

Those midbass drivers are beautiful! Hope you can wedge them in without having them stick out the sides of your doors!


----------



## cvjoint

ecbmxer said:


> Those midbass drivers are beautiful! Hope you can wedge them in without having them stick out the sides of your doors!


Sure are! I'm going back to hardcore to make these fit. The current setup is an endoskeleton: fiberglass reinforced sheetmetal baffle. It reduces panel flex a bit.

For the Scans I will do an exoskeleton: pure fiberglass door panel bolted to the edges of the door. Here's how it came out in the Accord, 10" midbass:


----------



## denetnz

OK, I just got my 18WU Scans in (together with the rest of my new system - see signature) and did a 10 minute tune with trueRTA. Currently crossed at 2.5kHz, 24db/octave.

Subjective opinion, after a couple of tracks: WOW!!! They Absolutely Rock!!! 

My doors are not sealed at all and are leaking like sieves at present (no door cards, sound deadening hanging loosely over over gaping holes) and still the bass is phenomonal! 

What's more, my door cards will still go back on looking completely stock. Admitedly the windows don't go right down anymore, but who cares - I have air-con and don't ever drive with the windows down anyway due to wind noise.


----------



## ErinH

Welcome to the club. 

I'm running the 18wu's in the kicks, 12mu's on the dash, and the ring illuminators next to the mids. I feel like a pig in mud (hog heaven).


----------



## cvjoint

I ran the Illuminator on my desk decoupled with a towel. No bueno, it rattled my entire desk. Now it's sitting on a tissue box with the vent firing in the tissue box. The tissue box itself had to be decoupled with a towel. My keyboard still jumps up and and about.


----------



## cvjoint

So I was modeling some Faital combinations. 

1. Single Faital in large box


2. Three Faitals in 1/10th the box size


Option 1 has better group delay behavior without crossovers. The funny thing is, option 2 doesn't need a HP filter. The box is so small it virtually acts as strong spring keeping the midranges under xmax all the way down to 30hz at 150w. Basically it needs no crossover. After a crossover is implemented in option 1 group delay is at times 4 times worse than the array and never better.

Seems like option two would get 10db+ more output as well as better group delay.


----------



## subwoofery

cvjoint said:


> So I was modeling some Faital combinations.
> 
> 1. Single Faital in large box
> 
> 
> 2. Three Faitals in 1/10th the box size
> 
> 
> Option 1 has better group delay behavior without crossovers. The funny thing is, option 2 doesn't need a HP filter. The box is so small it virtually acts as strong spring keeping the midranges under xmax all the way down to 30hz at 150w. Basically it needs no crossover. After a crossover is implemented in option 1 group delay is at times 4 times worse than the array and never better.
> 
> Seems like option two would get 10db+ more output as well as better group delay.


Better group delay in which range? From what I've read, it's more important to have a consistant group delay (in the range you're using the driver) than a flat group delay that swings up at a certain point. 
It's true though that no Xover is better unless you use it to your advantage - like with bandpass enclosures... 

Kelvin


----------



## cvjoint

You be the judge:

Red is single driver in a 10x larger box with the needed crossover
Yellow is the 3 drivers in 1/10th the box without a crossover, doesn't need it
Aqua is the 3 drivers with some eq. to get rid of the peak, -4db at 300hz

Green is the scan midbass with all the crossovers on.


----------



## subwoofery

cvjoint said:


> You be the judge:
> 
> Red is single driver in a 10x larger box with the needed crossover
> Yellow is the 3 drivers in 1/10th the box without a crossover, doesn't need it
> Aqua is the 3 drivers with some eq. to get rid of the peak, -4db at 300hz
> 
> Green is the scan midbass with all the crossovers on.


Try your Scan with a shallower slope, you'll see that your MAX Xmax is going to be lower - therefore you'll be able to HP lower. 
I've posted this in one of your thread: 
http://www.diymobileaudio.com/forum/1429203-post30.html 
You should get lower distortion since the MAX Xmax is lower with the shallow slope (keeping the Xover point the same) *AND* a better group delay... 

Kelvin


----------



## cvjoint

subwoofery said:


> Try your Scan with a shallower slope, you'll see that your MAX Xmax is going to be lower - therefore you'll be able to HP lower.
> I've posted this in one of your thread:
> http://www.diymobileaudio.com/forum/1429203-post30.html
> You should get lower distortion since the MAX Xmax is lower with the shallow slope (keeping the Xover point the same) *AND* a better group delay...
> 
> Kelvin


Well, like I said then, you get a lower excursion for a few hz but then a larger excursion for everything bellow that. The total distortion is going to be higher. This would apply to the 63hz HP. For the LP at 200hz reducing the slope will affect sound staging a bunch if you start to localize the door speaker.

With that said 12db at 200hz on the single Faital seems reasonable but at the same time it doesn't reduce group delay bellow the equalized trio. The negative impacts of the crossover on group delay overwhelms the gains from a low Q.


----------



## subwoofery

cvjoint said:


> Well, like I said then, you get a lower excursion for a few hz but then a larger excursion for everything bellow that. The total distortion is going to be higher. This would apply to the 63hz HP. For the LP at 200hz reducing the slope will affect sound staging a bunch if you start to localize the door speaker.
> 
> With that said 12db at 200hz on the single Faital seems reasonable but at the same time it doesn't reduce group delay bellow the equalized trio. The negative impacts of the crossover on group delay overwhelms the gains from a low Q.


I'd actually like to see a distorsion plot with one driver HP at 12dB/oct and one at 24dB/oct - keeping the Xover point the same. Distorsion plots we see are usually full-range. But seeing the post in "Awesome klippel news", I don't think we'll be able to see much @ a high enough level... 
If you keep your driver within it's MAX Xmax, I don't see distorsion being a problem. I remember Erin using his Illum 7" without HP (Aperiodic membrane) and I don't think distorsion was a problem. 

I still feel that keeping Xmax within its range is better than going over Xmax for a few freqs. Since going over Xmax happens higher in the response (shouldn't be a problem with the Illum since it happens below 50Hz), you'll actually be more inline to hear it. 
Let's take a driver that has been Klippeled: AE TD6H (Xmax set to 6.3mm)








Again, please remember that Xmax is kept within its range and is slowly decreasing on the bottom end anyway... I don't see why distorsion would be higher @ 40Hz (Xmax 5mm) than @ 100Hz (Xmax also 5mm). Ok distorsion @ 40Hz would be more important with the 12dB/oct slope compared to 24dB/oct slope but since 100Hz isn't a problem, why would 40Hz be one even with the 12dB/oct slope? 

Kelvin 

PS: I'm not talking about LP since it doesn't affect group delay and Xmax. So yes, a steep slope on the LP is usually prefered to keep interaction between drivers to a minimum for better imaging.


----------



## cvjoint

subwoofery said:


> I'd actually like to see a distorsion plot with one driver HP at 12dB/oct and one at 24dB/oct - keeping the Xover point the same. Distorsion plots we see are usually full-range. But seeing the post in "Awesome klippel news", I don't think we'll be able to see much @ a high enough level...
> If you keep your driver within it's MAX Xmax, I don't see distorsion being a problem. I remember Erin using his Illum 7" without HP (Aperiodic membrane) and I don't think distorsion was a problem.
> 
> I still feel that keeping Xmax within its range is better than going over Xmax for a few freqs. Since going over Xmax happens higher in the response (shouldn't be a problem with the Illum since it happens below 50Hz), you'll actually be more inline to hear it.
> Let's take a driver that has been Klippeled: AE TD6H (Xmax set to 6.3mm)
> 
> 
> 
> 
> 
> 
> 
> 
> Again, please remember that Xmax is kept within its range and is slowly decreasing on the bottom end anyway...
> I think we regard xmax in different ways. For you it's more like a dummy variable (either audible or not) or an actual threshold. For me it's just forecasted 10% distortion, it's called xmax. 9% can be called something else, we can be cocky and call it "fairwater". I see xmax as being important in the sense that it's one way to summarize klippel results (at a loss of information) for comparison purposes.
> 
> I see distortion as a countinuous variable and I want as little as possible. We're not talking differences of .002 like in amplifiers, but a change from 1% to 8% is noteworthy to me, i don't care that it's under fairwater. If I had a choice I'd want to minimize distortion such as the integrated distortion over 20-20khz and weighted by the equal loudness curve is as little as possible. I do think that the stuff under the crossover aggregates to a lot more than you save for a few hz.
> 
> Secondly you will have another driver operating under the crossover, the subwoofer. It too will produce distortion. That distortion will add up on top of whatever your midbass is producing. If you believe you can't hear any distortion under fairwater then you should make sure the sum doesn't go over. Your reference point is all of a sudden a bad rule of thumb isn't it?
> 
> I don't see why distorsion would be higher @ 40Hz (Xmax 5mm) than @ 100Hz (Xmax also 5mm). Ok distorsion @ 40Hz would be more important with the 12dB/oct slope compared to 24dB/oct slope but since 100Hz isn't a problem, why would 40Hz be one even with the 12dB/oct slope?
> 
> 100hz distortion is a problem, we just can't help it, the fundamental has to be reproduced at whatever cost.
> 
> Kelvin
> 
> PS: I'm not talking about LP since it doesn't affect group delay and Xmax.
> But it does. Specify a LP filter on your driver at 200hz. Then click and unclick it on the group delay screen. You should see some notable changes in group delay.
> So yes, a steep slope on the LP is usually prefered to keep interaction between drivers to a minimum for better imaging.


Another reason to use steep slopes is IMD. Think about how it is produced when a driver has to reproduce a high excursion note like 40hz at the same time as frequencies much higher in the spectrum. The more you reduce concomitant excursion the lower the IMD.


----------



## denetnz

subwoofery said:


> I remember Erin using his Illum 7" without HP (Aperiodic membrane) and I don't think distorsion was a problem.


Was that 'Aperiodic membrane' just a typical leaky door or was there more to it than that?


----------



## cvjoint

denetnz said:


> Was that 'Aperiodic membrane' just a typical leaky door or was there more to it than that?


I think he has kicks, and therefore a need for room.


----------



## subwoofery

cvjoint said:


> I think we regard xmax in different ways. For you it's more like a dummy variable (either audible or not) or an actual threshold. For me it's just forecasted 10% distortion, it's called xmax. 9% can be called something else, we can be cocky and call it "fairwater". I see xmax as being important in the sense that it's one way to summarize klippel results (at a loss of information) for comparison purposes.
> 
> I see distortion as a countinuous variable and I want as little as possible. We're not talking differences of .002 like in amplifiers, but a change from 1% to 8% is noteworthy to me, i don't care that it's under fairwater. If I had a choice I'd want to minimize distortion such as the integrated distortion over 20-20khz and weighted by the equal loudness curve is as little as possible. I do think that the stuff under the crossover aggregates to a lot more than you save for a few hz.
> I've taken down the slope for my midbass to 12dB/oct slope in both of my cars and it did not seem to produce more distortion than before yet the illusion of upfront bass is much improved - well I guess it's because I'm not a believer for low Xover point in the midbass region (aka 40Hz-50Hz)
> I understand you want 1% distortion at a high enough SPL (I guess 110dB+) within the 20Hz-20kHz range - but I feel that using a shallower slope, even if you have to bring your HP point a bit higher (from 50Hz to 63Hz), has more benefit in the group delay than keeping a steep slope (@ 50Hz).
> Better group delay, keeping your driver in the "safe zone" (less than 10% distortion point), if you are used to high Xover point over the subwoofer = better upfront bass without the added distortion, seems like a WIN-WIN-WIN situation.
> 
> Secondly you will have another driver operating under the crossover, the subwoofer. It too will produce distortion. That distortion will add up on top of whatever your midbass is producing. If you believe you can't hear any distortion under fairwater then you should make sure the sum doesn't go over. Your reference point is all of a sudden a bad rule of thumb isn't it?
> ^ agree with that statement - that's why I choose a subwoofer that minimizes distortion with its motor topology (XBL^2) and use of shorting rings...
> 
> 100hz distortion is a problem, we just can't help it, the fundamental has to be reproduced at whatever cost.
> 
> But it does. Specify a LP filter on your driver at 200hz. Then click and unclick it on the group delay screen. You should see some notable changes in group delay.
> Ok, I should have been more clear, it doesn't affect the shape too much compared to the HP  I see HP slopes as being more important regarding group delay...
> 
> Another reason to use steep slopes is IMD. Think about how it is produced when a driver has to reproduce a high excursion note like 40hz at the same time as frequencies much higher in the spectrum. The more you reduce concomitant excursion the lower the IMD.
> That's why we all need to choose our Xover point wisely. In my TD6H example above, which is going to sound uglier (more distortion)?
> 1# 12dB/oct slope: 60Hz (highest point @ 6.1mm) note being played and at the same time a frequency much higher in the spectrum
> 2# 24dB/oct slope: 70Hz (highest point @ 6.5mm) note being played and at the same time a frequency much higher in the spectrum
> _Second quizz_
> 1#bis 12dB/oct slope 40Hz (5mm Xmax) note being played and at the same time a frequency much higher in the spectrum
> 2#bis 24dB/oct slope: 55Hz (5mm Xmax) note being played and at the same time a frequency much higher in the spectrum


The above 2 questions are really honest questions... Am willing to accept anything as long as the explanation is too complicated for me  
No really, I'm here to learn, it just doesn't focus enough in my head to accept your answer ; I need more knowledge  

If you could simulate those for me with a distortion graph like you did the Faitals that would be great and help me a lot... Different slopes while keeping the Xover point the same. 20dB down from the fundamentals is 10% distortion, therefore, I believe you're chooting for -40dB which translates to 1% - correct?

Kelvin 

PS: sorry for taking your build thread a bit OT


----------



## cvjoint

The tradeoff between HD and group delay is what I regard as the black art in designing a speaker. I can't tell you which is the better of two evils I can just tell you what I would choose and I usually go for the steeper slope.


----------



## subwoofery

cvjoint said:


> The tradeoff between HD and group delay is what I regard as the black art in designing a speaker. I can't tell you which is the better of two evils I can just tell you what I would choose and I usually go for the steeper slope.


The more I think about it, the more I feel "arrays" and "cone confusion" is the way to go. 
Might try this for a next project... 

Kelvin


----------



## thehatedguy

But an array with more than 2 drivers will start to suffer from combing and would need a minimum distance to really integrate as one source.


----------



## cvjoint

thehatedguy said:


> But an array with more than 2 drivers will start to suffer from combing and would need a minimum distance to really integrate as one source.


I thought combing occurs in 2 driver arrays as well. Nothing more occurs with the addition of another driver combing wise. Is there anything special about adding drivers on top of a pair?


----------



## ErinH

cvjoint said:


> I think he has kicks, and therefore a need for room.


Correct. Mine are ap'd to the outside of the car.


----------



## cvjoint

The Satori is out:










Satori Woofer MW16P

Seems to have about half the throw of the Illuminator based on Klippel tests. This is supposed to be SB's top end driver. It looks like one. The performance is on par with the Vifa it seems, far from touching the Illuminator. It costs a pretty penny too.


----------



## thehatedguy

It will occur with 2 drivers, but anything over 2 drivers will need special attention paid to it...Jeff mentioned this over on the other forum. 2 speaker arrays do not need any sort of signal steering or power tapering...but I think you would need to do that with a 3 speaker array as the C-T-C spacing rules start to apply.

Or play that tweeter LOW.

Can sim it in EDGE I think.



cvjoint said:


> I thought combing occurs in 2 driver arrays as well. Nothing more occurs with the addition of another driver combing wise. Is there anything special about adding drivers on top of a pair?


----------



## thehatedguy

Erin has aleady tackled that comparo on the PE forum.



cvjoint said:


> The Satori is out:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Satori Woofer MW16P
> 
> Seems to have about half the throw of the Illuminator based on Klippel tests. This is supposed to be SB's top end driver. It looks like one. The performance is on par with the Vifa it seems, far from touching the Illuminator. It costs a pretty penny too.


----------



## ErinH

Yea. About $50 less than the illuminator iirc. I voiced my displeasure over the results on techtalk and it want received too well. Guess people don't like to be told the newest toy still can't top one that's three years old. 
Funny thing is that, I might have heard someone say that SB purchased a klippel after seeing some data posted for all to see ... Wonder what may happen in the future.


----------



## cvjoint

bikinpunk said:


> Yea. About $50 less than the illuminator iirc. I voiced my displeasure over the results on techtalk and it want received too well. Guess people don't like to be told the newest toy still can't top one that's three years old.
> Funny thing is that, I might have heard someone say that SB purchased a klippel after seeing some data posted for all to see ... Wonder what may happen in the future.


I'm confused. When I look at the Illuminator I could put money on it that Scan has an in-house Klippel or at least uses one for the various pre-production units. SB is supposed to have the brains from Scan that just migrated over. So what is going on here? I expected the Satori to give the Illuminator a run for its money and look well optimized. Neither materialized.

On second look it does look noticeably better than the Vifa but has some unusual distortion at 1.2khz. 



hatred said:


> It will occur with 2 drivers, but anything over 2 drivers will need special attention paid to it...Jeff mentioned this over on the other forum. 2 speaker arrays do not need any sort of signal steering or power tapering...but I think you would need to do that with a 3 speaker array as the C-T-C spacing rules start to apply.
> 
> Or play that tweeter LOW.


I was thinking of doing:
_M_________M_
TM_________MT
_M_________M_

Is this over the top? Should I just do a traditional MTM with the tweeter offset?


----------



## thehatedguy

I think the Satori was supposed to be an Illuminator killer..it sure borrowed from the looks department.


----------



## ErinH

thehatedguy said:


> Erin has aleady tackled that comparo on the PE forum.


Yea. Jeff B sure didn't like my take on it. It became pretty petty ...


----------



## cvjoint

I don't know why that guy kept on defending the irregularity at 1.2khz. It shows in the FR, HD, and CSD. That's usually good enough for someone to take note of it. 

I suppose one of the benefits of the Satori is wide bandwidth, but who wants to play into the beaming range so far? In HT especially you will end up sitting on the side of the couch at times. 

Erin, I've been thinking a lot about the IMD and MTD tests. I do find it's tough to believe HD is that important for a mid. Maybe these new tests is where most of the distortion lies. Do you want to put one of my Faitals against the Dyn and your Illuminator once you figure it all out? I have two more coming in the mail but I can route one to you. That way the driver is fresh and the testing is accurate.


----------



## ErinH

cvjoint said:


> I don't know why that guy kept on defending the irregularity at 1.2khz. It shows in the FR, HD, and CSD. That's usually good enough for someone to take note of it.


What aggravated me was that he seemed annoyed that I kept mentioning the Illuminator performed better. He said it wasn't a competition, but someone also noted the title of the thread. After that, though, I lost respect for the dude. Like I said, it just seemed like it became petty when I was simply trying to point out the data showing the Illuminator _clearly_ performing better.



cvjoint said:


> Erin, I've been thinking a lot about the IMD and MTD tests. I do find it's tough to believe HD is that important for a mid. Maybe these new tests is where most of the distortion lies. Do you want to put one of my Faitals against the Dyn and your Illuminator once you figure it all out? I have two more coming in the mail but I can route one to you. That way the driver is fresh and the testing is accurate.


I'm game. Just give me some more play time. I'm actually a bit more acclimated to the new setup than I was a few days ago. I just need time to do some test runs to make sure I have some efficiency and then I'll post up the Dyn results in a new thread. I've already got LPM & LSI completed. I'm just playing with FR/HD/IMD and making sure the baffle I'm using isn't imparting any resonances that show up in my measurements. So far, though, I've not found any evidence of this.


----------



## thehatedguy

I had a feeling there might have been some vested interest in the PE thread.


----------



## cvjoint

Ok, I'm leaning more and more towards an MTM setup with the tweeter offset towards the windshield. As opposed to the MMT, MTMM setups is should increase clarity since the tweeter is symmetrically close to both mid centers. The offset should reduce diffraction and reflections off of the side windows. 

The challenge with an MTM setup is getting the tweeter at ear level. I will have to install the top mid as high as possible in the pillar to nudge the tweeter at ear level. Center of the tweeter to center of the mid will be only 3" allowing for a rather high xover point. CTC dictates a xover point of 4,5khz at most. Beaming starts at 4khz horizontally. I'm thinking either 3.1khz or 4khz should be good places to cross. 4khz might allow the Scan tweeter to hold on to the mid output. The small format 3/4 dome is tits for MTM, doesn't beam till 18khz and allows for very low CTC spacing.

I like the idea of MTM so much that I think I would use the same system in a home. The only difference would be to combine the midbass and sub as one driver under the MTM. The only reason I run 4 way in a car is because I can't mount my subs where my midbasses are, or I would and run a 200hz LP on the suckers.


----------



## cvjoint

*MMT to MTM changeover
*
Some pics:
Glued aluminum sheet to 1/4 birch. The Gorilla glue gave out while cutting. I recommend something better. The aluminum is a necessity since the 3/4 small format tweeters are a ***** and 1/2 to mount in birch and the like. The 1/4" birch sheet on top is the exact size the Faitals and Scan tweets require to flush mount. 









I used the router to make the OD. Perfect tool for the job, I just had to adjust it exactly to 1/4" inch so I don't cut into the aluminum:

















The inside was cut using a hole saw. Temporarily mounted in the car:


















Review:
Nothing I can do to test here except perhaps a FR plot later. The impression I get is that this MTM was the closest setup to a point source I heard before (abstracting from fullrange setups). The clarity is remarkable. With the MMT setup I thought I couldn't pick up the tweeter and mids separately but compared to this they seemed quite diffuse now. The center to center spacing is 3". This means a xover point up to 4,500hz is ideal in the far field using the rule of thumb. In the nearfield I think 2,250hz or less is ideal. I tried 2, 2.5, 3.1, and 4khz as crossover points on vocal tracks. I honestly cannot tell a difference. It sounds like one driver. At 5khz and above it sounds a bit hollow so maybe that's the audible limit. To my ears the usual CTC 1 wavelength rule works better. 

I'm quite stoked with the CTC spacing I managed to get. The baskets are almost touching eachother. Without the Faital trick flange I would be at 4" at least with a 4.5" mid. 

The MMT seemed to have sounded more like a wave of sound, maybe a bit more unreal but pleasing nonetheless. The MTM feels closer to reality but MMT was pretty neat as well. Overall advantage MTM, the clarity is ridiculous.


----------



## cvjoint

Another effort to pick up comb filtering:










another fail. The blue plot is the Faital combo playing the same frequencies 1khz-20khz. The black plot is the Scan tweeter, a single driver that doesn't have comb type problems. This time around I did not average multiple mic positions, I did not smooth the plots at all either. Me thinks the reason why comb filtering is so controversial is because it's not all that visible/audible unless it's extreme.


----------



## fish

To me, it looks like that first major dip on the Faitals is @ 2.25k. From this graph, is that where you got your crossover point (2 posts above), or just doing the CTC math?


----------



## cvjoint

fish said:


> To me, it looks like that first major dip on the Faitals is @ 2.25k. From this graph, is that where you got your crossover point (2 posts above), or just doing the CTC math?


Lycan/Warewolf was recommending a half wavelength rule of thumb for center of tweeter to center of woofer spacing in nearfield based on some research paper. In the tests above the tweeter and mids are tested separately so there should be no comb resulting from tweeter and mid interaction near the xover.

What I thought I would find is that the two mids playing together would form a comb pattern that is more pronounced in the higher frequencies. Oddly enough you are right, there is a long narrow dip at 2,25hz but it's also present in the tweeter. In fact there are lots of long narrow dips in both plots. I believe this may be due to reflections. There is no increase in comb patterns accentuated in the mid plot, and that's what I was checking for. Maybe reflections are creating more nulls than two mids playing together on a pillar ever could.


----------



## ErinH

You're going to have to measure outside of the car and gate the response time. Shouldn't be hard. Just rig up something outside where the drivers are off the ground about 4-5ft (to get you accurate low end response) and measure it. You'll never see CTC filtering issues with an in-car response due to the reflections off everything else; not unless you're able to gate the measurement in a manner that removes all the surrounding reflections. Which, might work... but measuring outside of the car will tell you for sure if there's a problem. I measure my pillar pods outside of the car first before inside the car so I can make sure I'm able to discern the issues with the pillar itself rather than decipher the dash/windows influence.

Here's what I did if you're interested:
http://www.diymobileaudio.com/forum/1486639-post1377.html


----------



## cvjoint

bikinpunk said:


> You're going to have to measure outside of the car and gate the response time. Shouldn't be hard. Just rig up something outside where the drivers are off the ground about 4-5ft (to get you accurate low end response) and measure it. You'll never see CTC filtering issues with an in-car response due to the reflections off everything else; not unless you're able to gate the measurement in a manner that removes all the surrounding reflections. Which, might work... but measuring outside of the car will tell you for sure if there's a problem. I measure my pillar pods outside of the car first before inside the car so I can make sure I'm able to discern the issues with the pillar itself rather than decipher the dash/windows influence.
> 
> Here's what I did if you're interested:
> http://www.diymobileaudio.com/forum/1486639-post1377.html


I see what you mean. Ok, say I do take out the pillar and there is obvious comb filtering going on between the two mids if I cross high. If the interior of the car negates the difference between a tweeter and two mids covering the same portion what would you do about it? 

I would think comb filtering is "averaged out" by the multiple reflective panels in a car. This might be a benefit of the car interior wouldn't it?

Btw, I would have loved to see CSD plots along with your FR pillar pod testing. Maybe the tweeter interactions would show up as blips in the response at longer time intervals. This too is an effect that is probably averaged out in the car interior but I would be curious to see it.


----------



## cvjoint

double


----------



## cvjoint

Well ****, the Faitals didn't test to my expectations. There are two ways to go from here:

1. Save the MTM arrangement but get different 4" drivers. I'm open to suggestions on what driver up to 105mm or so in diameter and no more than 45mm deep I could use. Here is the current setup:










2. Try a true line array. I'm thinking three 3" drivers squeezed next to 6 tweeters or so. See this but imagine my car pod:










I'm leaning towards three Fountek FR88s:









6 Daytons ND16:









The Fountek 89ex models might be better simply because the 88 model looks like it could blind me while driving. The Dayton is good enough for 3.1khz cross and narrow enough to allow close spacing.


----------



## t3sn4f2

Bargain Mini - using ND20FB

I know it's not the same tweeter, but it's still in the same quality control range I imagine. Maybe something to think/worry about.......


----------



## cvjoint

t3sn4f2 said:


> Bargain Mini - using ND20FB
> 
> I know it's not the same tweeter, but it's still in the same quality control range I imagine. Maybe something to think/worry about.......


A tad bigger. In the same thread they talked about this Aura using the same mount:









The Illuminator 7", Fountek, and Aura together would all be underhung neo metal drivers! Looking at Zaph tests the Aura is the better of the three. Plus better build quality apparently.


----------



## Brian Steele

t3sn4f2 said:


> Bargain Mini - using ND20FB
> 
> I know it's not the same tweeter, but it's still in the same quality control range I imagine. Maybe something to think/worry about.......


I wouldn't use that driver, or the Aura equivalent. I've used both in my car, and end up going with the ND16. I much prefer the sound of the ND16. Just watch your x-over point.


----------



## cvjoint

t3sn4f2 said:


> Bargain Mini - using ND20FB
> 
> I know it's not the same tweeter, but it's still in the same quality control range I imagine. Maybe something to think/worry about.......


You gave me a great idea. Bad quality control can be good! Think that I will not have the 15 channels of processing this kinda setup requires for optimal time allignment and level setting. If I simply parallel drive every row of drivers the output of the top one is higher than the bottom and the TA is a bit skewed too as it sits closer.

Nothing i can do about TA without extra DSP but bad quality control can correct the output difference which imo will be the greatest challenge. I can round up all 12 tweeters and all 6 mids and test them for output ability. The more sensitive ones end up on the bottom and the least sensitive on top. This way there is an inherent output matching.


----------

