# Co-ax midbass/horn speakers



## oabeieo

On another build thread I just saw a really amazing set of kicks that have pretty big sealed enclosures for 8s in a civic. 

It really got me thinkin about how awesome it would be to do a co-ax midbass in his setup. And would consider trying something similar. But to do it the way he did not a chance in hell of getting a under dash horn to go. 

I saw a few nice b&C co-ax, some beymas , ciares, 18sounds, etc...

Using the speaker cone as the waveguide what are the downsides to that and how would it work in a kick in a car? 

Being the horn body is moving would that cause intermodal distortion? 

I can imagine the phase between horn and cone would be easy to nail down and stage depth would be really good. Yeah it would lack dispersion control but would be on axis enough to at least make one hell of a single seat position car. 

Any thoughts on using a co-ax midbass/horn? 
Pros cons ? 

Thanks in advance , 
:cheers:


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## ErinH

Well, the first thing is finding a good coaxial pro audio driver. They're not that plentiful and unfortunately the better ones tend to be larger (12" tannoy, bms, b&c, radian were typically the better ones). Just, in general it seemed the best ones in regard to mouth/waveguide termination were 12 inch drivers. If you use a coaxial 12" pro-audio driver you now have two problems: you'll need to cross it higher than standard sensitivity woofers simply because of it's higher Fs AND to mitigate the HF non-linearity due to the cone (which is the waveguide) moving. The more the cone moves, the more non-linearity you have in the response. I proved this out with my kef 5" years back which you can read about here and see the results of below. You'd have to do some trial and error with your own woofer but let's just say 100hz was the best balance you could strike for a 12" in order to limit this non-linearity to a point where it's not offensive. Even that may be too low. 


Here's my testing of the tweeter's response as the midwoofer cone was at rest, 3mm outward and 3mm inward:


> I thought it would be interesting to see how the position of the woofer cone impacts the frequency response of the tweeter. This matters when you’re listening to music and isn’t captured by a standard sine sweep. To measure this performance I simply connected a 9v battery to the woofer’s terminals in positive polarity, then negative polarity which resulted in an approximate +/-3mm shift in cone direction. I ran a sine sweep over the tweeter while the woofer was a) at rest, b) fixed out, and c) fixed in. The pictures below show illustrate this.
> 
> Woofer at rest:
> (see site)
> 
> Woofer fixed out:
> (see site)
> 
> 
> 
> Woofer fixed in:
> (see site)
> 
> 
> The following results are of the three positions discussed above overlaid on one another. The lines are labeled per the woofer position.
> 
> Note: The SPL level is not absolute here. I performed the test at the same volume level throughout but it is not intended to reference any set test paraemter such as 2.83v/1m or 1w/1m.




Again, the results above are with only 3mm movement. So, if you're using a driver capable of more throw than this you can imagine the results would only get worse. Of course, with more surface area you may not *need* a lot of throw but I imagine the crossover would have to be relatively high to keep excursion 3mm or less for a pro-audio driver. Sims should show this, though, if you want to vet it out. And various drivers have different cone shapes so the impact on the non-linearity of the HF response will change ... that would have to be tested.







With an 8" I was planning on trying 100hz but I have a feeling I would have settled closer to 120-150hz based on the excursion I needed vs being safe. Then you have to factor in mating a subwoofer to a driver to the situation. There'd be no room up front anymore ... and *properly* blending a subwoofer that is behind you gets harder (not impossible) the higher you place the midbass/subwoofer crossover.


Will the system get loud? Absolutely. Can it sound good? Sure. Can it sound great? That's harder. Goals vary... ultimately it's not something I did for various reasons. Some covered above.


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## ErinH

^ the above is obviously a "YMMV" type post but again the impact of the moving cone is not to be ignored considering it is the waveguide for the tweeter and therefore IMO as important as the waveguide shape and termination itself.


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## oabeieo

Thanks Erin , 
Ive been very interested in the co-ax pa speakers. After seeing your car it just made sense but I know Nothing about them. 

The k100 you show looks like a nice driver. But the problems you list sure are sobering. And your data really tells a lot about the behavior of the driver and I would assume the non- linearities would make it a rough go to say the least. 

I just didn't know if the cone moving had that much of an impact; got me thinkin twice now. 

I've seen a few co-ax horn loaded drivers where the horn is plastic and floats above the cone , surely a high crossover would be an order, and that may or may not be that bad if axis wasn't more than 10 to 20° . - 

I've never heard a set wild love to audition some maybe bows not the time


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## oabeieo

Didn't wanna post bomb your build - thx for replying 

- so if these co-ax PA horn/midbass speakers have issues how bad is it at the end of the day?

Let's just say someone was to build kicks (and totally copycat Erin's ) 
And throw in a 8"/horn co-ax And got the responce flat and just tuned it best it could. How listenable would it be? Would it completely **** the bed or would it be pretty good? 

I understand there's some sort of trade off with everything somewhere, anyone think it would be decent ? 

Thx in advance


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## Patrick Bateman

Random observations:

1) The B&C 5" coaxes are pretty nice, but they're also expensive and the speaker is hyoooge. Not sure if they're good for a car really.

2) The 3" KEF coaxes are seriously underrated and can be readily found on eBay for under $50 each. On the downside, when you're using these really tiny coaxes the performance isn't a whole lot difference from a full range. If you put a blindfold on me I'm not sure I could tell the difference between a 3.5" Fostex full range a and a 3" KEF coaxial.

3) The bigger KEF coaxes leave me a little cold. Something wrong in the midrange.

4) The mid-size KEF coaxes seem to be a 'sweet spot' between the 3" coaxes and the 6.5" coaxes. The KEF LS20 sounds fabulous.

5) Dave Smith from KEF/Bose/Snell/JBL/McIntosh has said that the best coax performance he's ever seen was from a ceiling mounted speaker that uses a 'bridge' for the tweeter. (Picture the speakers from NEXO, but with a tweeter mounted in the bridge.) I'm inclined to believe Dave because the bridge seems to solve a lot of problems. Even better, it's well within the realm of a DIY'er

6) If you're considering a coax, just go full retard and make a Synergy Horn


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## 94VG30DE

Patrick Bateman said:


> The KEF LS20 sounds fabulous.


+1, I can confirm this.


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## ca90ss

I've been running the B&C 8cxn51's in one car for a few months now and I can honestly say I prefer them over the horns in my other car. There is less than 1db difference in maximum output between them and they require significantly less tuning than the horns.


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## dcfis

oabeieo, you live in Denver so there should be a good Studio/live performance rental shop where you can rent studio monitors some of which have unique waveguides PreSonus, pioneer, namm and equator off the top of my head. Elac(Andrew Jones) is doing this in monitors also. Id like to snatch a pair of those and try


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## sh.moto.2

I have some 8inch coaxial that was designed for my company by a well known guy from this page. I wanted a driver that had outstanding midrange quality and ended up using a larger midbass to minimize coaxial movement


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## thehatedguy

Did Eric make those for you?


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## bassfromspace

ca90ss said:


> I've been running the B&C 8cxn51's in one car for a few months now and I can honestly say I prefer them over the horns in my other car. There is less than 1db difference in maximum output between them and they require significantly less tuning than the horns.


More details please. Specifically, are you using them for midrange/midbass duty or strictly as a midbass?


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## ca90ss

bassfromspace said:


> More details please. Specifically, are you using them for midrange/midbass duty or strictly as a midbass?


They're crossed at 80-2000hz on the lf side and 2k and up on the hf drivers powered off a Focal FPD900.6 so I have 300w available on the mid and 75w on the hf drivers.


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## bassfromspace

Are they in kicks or doors? If kicks, are they vented to the atmosphere?


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## ca90ss

In the doors. I used them in sealed kick panels in my previous car and they sound better in the doors of my current car. I do need to do a lot more deadening though.


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## Elgrosso

Super interesting, i'd be really curious to hear some big coax like that.
How did you manage to fit them with this big depth in doors?
And so 80hz is ok? (i have hard time playing my 8mbx51 crossed here)


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## ca90ss

I have pretty deep doors, the only issue I had was the terminals for the hf driver are on the bottom of the driver so if you use connectors instead of soldering the wire to them it adds another 1/2" or so to the depth. I had to zip tie the wire to the basket to keep it from hitting the window. If I really needed to I could have added another spacer and fit something up to about 5" deep. They do pretty good at 80hz, not as good as the ported 12ndl76's in my other car but I really have no complaints all things considered.


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## ca90ss

Hadn't checked the B&C website in a while but I think I may have found something suitable for a pillar install in my next car.
B&C Speakers


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## Elgrosso

ca90ss said:


> I have pretty deep doors, the only issue I had was the terminals for the hf driver are on the bottom of the driver so if you use connectors instead of soldering the wire to them it adds another 1/2" or so to the depth. I had to zip tie the wire to the basket to keep it from hitting the window. If I really needed to I could have added another spacer and fit something up to about 5" deep. They do pretty good at 80hz, not as good as the ported 12ndl76's in my other car but I really have no complaints all things considered.


And did you have to aim them a bit? Horizontally or vertically
Must say this thread made me re-consider my next install (3way kick midbass/mids in door/mini horns).
Seems to ask for such a different layout of the drivers!

(And ported 12s in front! That must be something)


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## thehatedguy

If I can't get the TAD 2001s I have and the 2119s in up front, I am really thinking about radian 5210 coaxes in front.


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## ca90ss

Elgrosso said:


> And did you have to aim them a bit? Horizontally or vertically
> Must say this thread made me re-consider my next install (3way kick midbass/mids in door/mini horns).
> Seems to ask for such a different layout of the drivers!
> 
> (And ported 12s in front! That must be something)


No aiming, just a simple baffle. The 12's in my other car are rear mounted just behind the front seat but probably not for much longer. Still haven't made a decision, was leaning towards pulling the 12's and subs and replacing them with a pair of AE TD15's and then replacing the B&C 6mdn44's with a pair of PHL1120's I have and keep the horns but may just simplify things and try a pair of BMS 8cn552's with a single McCauley 6174.


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## Elgrosso

Great I just learned about another brand! This Mc Cauley it's something!

Thanks for the pic, so you said you prefered them over your horns.
So, just guessing here, does this mean that if there was any trade off on the radiation pattern (going off axis in doors compare to under dash horns),
it was counterbalanced by the fact that it's point source?
Coherence over stage maybe?


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## sh.moto.2

thehatedguy said:


> Did Eric make those for you?


YES sir


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## thehatedguy

I had asked him to build me some last year...or talked about the possibility of building some 8s or 10" coaxes for me.

Does the compression driver screw in the rear of the mid?


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## sh.moto.2

thehatedguy said:


> I had asked him to build me some last year...or talked about the possibility of building some 8s or 10" coaxes for me.
> 
> Does the compression driver screw in the rear of the mid?


YES the driver does screw on from the rear and the terminals are upside down to have good mounting clearance


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## chefhow

Its not exactly what you are looking for, but the Tannoy CMS801DC is a HE Coax that should work in a kickpanel install.

http://www.fullcompass.com/common/files/13325-datasheet.pdf


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## bassfromspace

ca90ss said:


> Hadn't checked the B&C website in a while but I think I may have found something suitable for a pillar install in my next car.
> B&C Speakers


Jeedus!

Are they available yet?


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## ca90ss

I couldn't find them for sale anywhere in the US otherwise I'd have a pair on the way. This is the only place I saw that had them for sale.
https://h-audio.de/Lautsprecher-PA/B-C/Coaxials/B-C-4CXN36-Coax-Neodym::2973.html

I may try emailing PE and US Speaker to see if either one can get them and how much they are.


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## bassfromspace

What's cool about the 4's, is you could do some metal dash pods from the guy in Germany. That'll allow for a relatively quick and simple install.

That 88db rating is worrying. That's for the woofer. The tweet is 99db.

Did you have to pare back the horn in your current system?


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## ca90ss

The 88db rating on the mid worries me a little too but I'm hoping that if they were on axis at ear level it may not be as much of a problem. Even if they don't work in car I could make a pair of computer speakers or something with them.

I have the gain on the mid channels up a little bit relative to the hf drivers but for the most part use the DSP to match them.


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## Patrick Bateman

ca90ss said:


> I couldn't find them for sale anywhere in the US otherwise I'd have a pair on the way. This is the only place I saw that had them for sale.
> https://h-audio.de/Lautsprecher-PA/B-C/Coaxials/B-C-4CXN36-Coax-Neodym::2973.html
> 
> I may try emailing PE and US Speaker to see if either one can get them and how much they are.


I hate to be a wet blanket, but here's why you don't want to use most of the coaxes out there. I'd be curious to get Erin's input because he scrapped his Kef coaxes in a hurry.









Vance Dickason measured the B&C 5FCX44 five inch coaxial. Note how the tweeter response is abysmal. This is caused by interference between the woofer and the tweeter. 20khz is less than an inch long, due to the very short wavelengths even the smallest bit of reflection or diffraction will trash your high frequency response.









Here's a pic that Erin posted of the LS50 woofer, note how Kef put all kinds of effort into minimizing the profile of the woofer surround, and the transition from woofer to tweeter. That's to address the things that I've mentioned.









Tom Danley knows what he's doing, and note how his own designs that use a coax woofer "feature" these peaks and dips in the high frequency response. I personally built a speaker using the 5" B&C coax, and while they're very easy to work with, I don't think the treble is competitive with what you can (easily) achieve from a Synergy Horn.









Here's the response of Danley's SH50. Note that the treble isn't perfect, but it's a lot better than a coax. Danley once told me that the current performance is much better; this is a nine year old measurement and he said that the current models are performing at a higher level.

Again, not trying to be a wet blanket, just suggesting that there's an affordable/easy way to take this up a notch. And if you don't believe me, look at the data that Vance Dickason and Tom Danley have posted:

http://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/40_Voice_Coil/2012/2012_11_Nov.pdf

Danley Loudspeakers | Danley Sounds Labs | Danley Sound Labs, Inc.


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## Focused4door

Building a bridge for the tweeter like Patrick mentioned before is worth trying, it should be really cheap and fairly easy to build. Seems like it would be as good as many other options.


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## Elgrosso

Patrick Bateman said:


> I hate to be a wet blanket, but here's why you don't want to use most of the coaxes out there. I'd be curious to get Erin's input because he scrapped his Kef coaxes in a hurry.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Vance Dickason measured the B&C 5FCX44 five inch coaxial. Note how the tweeter response is abysmal. This is caused by interference between the woofer and the tweeter. 20khz is less than an inch long, due to the very short wavelengths even the smallest bit of reflection or diffraction will trash your high frequency response.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Here's a pic that Erin posted of the LS50 woofer, note how Kef put all kinds of effort into minimizing the profile of the woofer surround, and the transition from woofer to tweeter. That's to address the things that I've mentioned.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Tom Danley knows what he's doing, and note how his own designs that use a coax woofer "feature" these peaks and dips in the high frequency response. I personally built a speaker using the 5" B&C coax, and while they're very easy to work with, I don't think the treble is competitive with what you can (easily) achieve from a Synergy Horn.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Here's the response of Danley's SH50. Note that the treble isn't perfect, but it's a lot better than a coax. Danley once told me that the current performance is much better; this is a nine year old measurement and he said that the current models are performing at a higher level.
> 
> Again, not trying to be a wet blanket, just suggesting that there's an affordable/easy way to take this up a notch. And if you don't believe me, look at the data that Vance Dickason and Tom Danley have posted:
> 
> http://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/40_Voice_Coil/2012/2012_11_Nov.pdf
> 
> Danley Loudspeakers | Danley Sounds Labs | Danley Sound Labs, Inc.


Do you think this high Q dip will be audible? 
With real dynamic music not sweeps or rta.
I don't know but I feel like it might just be an acceptable trade off.
Especially in car where we already have these dips everywhere.
Even if we tune the average etc, they're still there.


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## ca90ss

Patrick Bateman said:


> I hate to be a wet blanket, but here's why you don't want to use most of the coaxes out there....... I don't think the treble is competitive with what you can (easily) achieve from a Synergy Horn.


I'm not going to argue that a synergy horn isn't a better option because they do have the potential to be better. I think we differ greatly on our definition of easy though unless you know of a prefab synergy horn that is already molded to my dash that I can buy off the shelf. I personally don't have the time or desire to spend hundreds of hours modeling and printing dozens of different designs that look like they were carved with a butter knife until I find one that may hopefully work in my car and then try to install them in a way that doesn't look like someone took a dookie on my dash. On the other hand I can install a pair of coax drivers in less than a day and get on with my life.


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## bassfromspace

ca90ss said:


> I'm not going to argue that a synergy horn isn't a better option because they do have the potential to be better. I think we differ greatly on our definition of easy though unless you know of a prefab synergy horn that is already molded to my dash that I can buy off the shelf. I personally don't have the time or desire to spend hundreds of hours modeling and printing dozens of different designs that look like they were carved with a butter knife until I find one that may hopefully work in my car and then try to install them in a way that doesn't look like someone took a dookie on my dash. On the other hand I can install a pair of coax drivers in less than a day and get on with my life.


Yep... I've got a 4 year old. Time's not my friend.


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## Elgrosso

Just got a pair of the 8CXN51 that I'm eager to try, really intrigued by these.
If they fit my door boxes for a temp test I'll check next week end, if not it will take time I'll finish my midbass first.
There are so many coold coaxial drivers out there!
Ex: RCF - CX10N251
Or
12cn860


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## Patrick Bateman

ca90ss said:


> On the other hand I can install a pair of coax drivers in less than a day and get on with my life.












but what if audio is your life?


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## oabeieo

Elgrosso said:


> Just got a pair of the 8CXN51 that I'm eager to try, really intrigued by these.
> If they fit my door boxes for a temp test I'll check next week end, if not it will take time I'll finish my midbass first.
> There are so many coold coaxial drivers out there!
> Ex: RCF - CX10N251
> Or
> 12cn860



 
Wow. 
That rcf looks mysteriously good. 
In fact , it might be a must try driver by all means.
has everything a car audio person would want. 

Nice find .


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## Izay123

oabeieo said:


> Wow.
> 
> That rcf looks mysteriously good.
> 
> In fact , it might be a must try driver by all means.
> 
> has everything a car audio person would want.
> 
> 
> 
> Nice find .




Looks tasty Except for the Low-ish Xmax potential & FIVE INCH MOUNTING DEPTH.

I feel like the best drivers that fall into this category have already been made--(& discontinued, unfortunately):












I wish these were still in production. Earlier this year, I got in contact with the (Now Former) CEO of Denon/MARANTZ/Boston Acoustics who was at the top when these were made. I was looking into whether someone still had the investment castings used to produce the woofer Baskets & waveguides.

Unfortunately, He told me that the SPZ speaker designer had since died, Boston Acoustics has now been sold twice since then, & The key components, I believe, were made in France. He Gave me the name of the Frenchman in charge of production at the time--Who has moved on as well--But it seems unlikely that any of those castings would still be hanging around-Especially when a new takeover company could destroy them & potentially claim a "loss" for a tax writeoff.....


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## oabeieo

Izay123 said:


> Looks tasty Except for the Low-ish Xmax potential & FIVE INCH MOUNTING DEPTH.
> 
> I feel like the best drivers that fall into this category have already been made--(& discontinued, unfortunately):
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I wish these were still in production. Earlier this year, I got in contact with the (Now Former) CEO of Denon/MARANTZ/Boston Acoustics who was at the top when these were made. I was looking into whether someone still had the investment castings used to produce the woofer Baskets & waveguides.
> 
> Unfortunately, He told me that the SPZ speaker designer had since died, Boston Acoustics has now been sold twice since then, & The key components, I believe, were made in France. He Gave me the name of the Frenchman in charge of production at the time--Who has moved on as well--But it seems unlikely that any of those castings would still be hanging around-Especially when a new takeover company could destroy them & potentially claim a "loss" for a tax writeoff.....


4.8mm linear is actually very good for a driver with a fs of 72hz, 
It's 30mm peak to peak, I wouldn't call that low-ish. I would say it's right where it should be for its design. 

You can do quite a bit with 4.8mm, most 6mm drivers fs is in the 50s-60s 
Almost everything with fs over 100hz is more like 3-0.5mm 

It just means this driver will play at full power down to about 125hz (12db) or lower with steeper filters. No doubt you could cross it at 70LR4 or 90BW4 safely without it getting spitty. 

With a sensitivity over 100db this thing would play effortlessly. would work fantastic as a midrange and horn with another midbass or woofer.

Yeah the Boston pro car coax miss were good, I used to sell a lot of those with prime series amps and entry level alpine 1bit cd decks back in the day.
The rcf is a totally different critter, Requires gobs of eq to work and a true engineer at the helm. Nothing against the Boston, like a says I sold those like no other , it was the only way to get garbage amps and cd decks to sound good out of the box with zero processing.

Pro audio drivers ; require a professional to set them up and need professional gear to use them the way they were intended. If you threw that rcf in a car with no proper eq it would be a disaster hands down. Where as the Boston would be listenable, put the right gear and the right ear at the controls and it's no comparison. The rcf would **** all over the Boston before 1/4 volume.


Iazy123 
How ya been buddy 
Do you have a build thread goin yet? We never finished talking last time, I saw a pic of the truck you were putting 10s in the door. 
I wanna check it out!


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## Izay123

oabeieo said:


> 4.8mm linear is actually very good for a driver with a fs of 72hz,
> 
> It's 30mm peak to peak, I wouldn't call that low-ish. I would say it's right where it should be for its design.
> 
> 
> 
> You can do quite a bit with 4.8mm, most 6mm drivers fs is in the 50s-60s
> 
> Almost everything with fs over 100hz is more like 3-0.5mm
> 
> 
> 
> It just means this driver will play at full power down to about 125hz (12db) or lower with steeper filters. No doubt you could cross it at 70LR4 or 90BW4 safely without it getting spitty.
> 
> 
> 
> With a sensitivity over 100db this thing would play effortlessly. would work fantastic as a midrange and horn with another midbass or woofer.
> 
> 
> 
> Yeah the Boston pro car coax miss were good, I used to sell a lot of those with prime series amps and entry level alpine 1bit cd decks back in the day.
> 
> The rcf is a totally different critter, Requires gobs of eq to work and a true engineer at the helm. Nothing against the Boston, like a says I sold those like no other , it was the only way to get garbage amps and cd decks to sound good out of the box with zero processing.
> 
> 
> 
> Pro audio drivers ; require a professional to set them up and need professional gear to use them the way they were intended. If you threw that rcf in a car with no proper eq it would be a disaster hands down. Where as the Boston would be listenable, put the right gear and the right ear at the controls and it's no comparison. The rcf would **** all over the Boston before 1/4 volume.
> 
> 
> 
> 
> 
> Iazy123
> 
> How ya been buddy
> 
> Do you have a build thread goin yet? We never finished talking last time, I saw a pic of the truck you were putting 10s in the door.
> 
> I wanna check it out!




Hey! I'm doing ok--Had a few setbacks, but overall I'm moving forward & progressing on the build. The 10's Sound just as good/or better & get louder than any other front subs I've heard so far! 

BTW those Boston's are the ~$1200 SPZ's: One step up from the Pro's. IMO they nailed SQ performance, output, Frequency range, Power handling, & Ease of install with this setup: Particularly with the SPZ50(in the picture above). They came with 24db biampable crossovers the size of bricks for each channel, & The provided crossover's performance in coaxial configuration with waveguides is as good or better than I could have done with Active crossovers myself. Check out the HUGE center channel crossover in the lower left center of the image below:












Once I get it sounding how I want, Ill plan to take the subs back out & trim down & Beautify LOADS of extra length of wiring, & put the DSP(s)? / Line drivers/I-O Contact blocks, etc down over the wheel well. Looks like I'll stay with the current Subs until I get serious about SPL--Maybe next year.

Looking forward to getting the tuning/wiring done so I can Make Beauty Panels for the top, front, & Back of the sub Enclosure, As well as Trim panels above that to flush/recess the amp until it's time to add more power.


I was able to score some sweet custom Team Z DC1500.4 Amps in exchange for my pair of LX's--Which worked out as a win-win: I could find the room for the DC's, & I liked the idea of fans & Low impedance capability, & My buddy needed amps that would fit in his trunk & sound great, because He's competing at SQ World finals in IASCA and MECA with those amps this month! I hope he wins!


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## Izay123

One more thing: YES, that is dual 12AWG OFC wire going to the center mid, with another pair for the tweet: I also ran Dual pairs of 12AWG OFC for each 4" mid upfront & same for Each 10" Front door Midbass/sub. Now I can get Max damping [email protected] 4ohms or Bridge each 10 at 1ohms & still sound decent with minimal line voltage droop!


Sent from my iPad using Tapatalk


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## oabeieo

Jimminy Christmas, that's a lot of power. 

Nice man! What's that in is that an expedition? 
You should get a build thread going, 
Post up measurements, pics of installs , it's a lot of fun. 



On the Boston , 
Aah yes , I remember those, your right , those were different. In fact an installer on mine has a set in his immaculate 90 civic 
He swears by them, they were very nice indeed , I've only herd his set. And seen them in magazines. 
The rcf would still walk it with its efficiency rating and proper eq and xo 
I'm sure it's a superb low efficiency driver that requires almost no eq, and for low level listening it could be a better chiloice especially with its ultra low resonance, but in the world of HLCD co-ax , the rcf would get a good 20db louder before breaking up. And the horn has a airy sound characteristic that is proffered to certain types of listeners, also the dynamic range because of the sensitivity, no heavy materials weighing it down absorbing all the detail at normal listening levels....etc ; diffrent animal all together. 

Start a build thread, just do it , it's fun!


----------



## Izay123

oabeieo said:


> Jimminy Christmas, that's a lot of power.
> 
> 
> 
> Nice man! What's that in is that an expedition?
> 
> You should get a build thread going,
> 
> Post up measurements, pics of installs , it's a lot of fun.
> 
> 
> 
> 
> 
> 
> 
> On the Boston ,
> 
> Aah yes , I remember those, your right , those were different. In fact an installer on mine has a set in his immaculate 90 civic
> 
> He swears by them, they were very nice indeed , I've only herd his set. And seen them in magazines.
> 
> The rcf would still walk it with its efficiency rating and proper eq and xo
> 
> I'm sure it's a superb low efficiency driver that requires almost no eq, and for low level listening it could be a better chiloice especially with its ultra low resonance, but in the world of HLCD co-ax , the rcf would get a good 20db louder before breaking up. And the horn has a airy sound characteristic that is proffered to certain types of listeners, also the dynamic range because of the sensitivity, no heavy materials weighing it down absorbing all the detail at normal listening levels....etc ; diffrent animal all together.
> 
> 
> 
> Start a build thread, just do it , it's fun!




I do personally like the sound of the "tamer" or "better behaved" horns for home speakers. I haven't had the chance of hearing horns in a car though. I think I was a bit too young to hear them in the Eric Stevens/ID horn Heyday.



Nice--I may start a build thread... still thinking about it.

It's a Range Rover in answer to your question..





Sent from my iPad using Tapatalk


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## Patrick Bateman

Focused4door said:


> Building a bridge for the tweeter like Patrick mentioned before is worth trying, it should be really cheap and fairly easy to build. Seems like it would be as good as many other options.


Did you see this? It worked extraordinarily well. It's what I listen to at my desk now.





































In particular, notice how the phase plug makes the sound of the loudspeaker consistent whether your ON axis or OFF. This is particularly important in car audio, where we're always listening off axis. It means that the reflected sound is consistent with the on-axis sound.

More here: Synergy Eggstravaganza - diyAudio


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## Elgrosso

oabeieo said:


> Wow.
> That rcf looks mysteriously good.
> In fact , it might be a must try driver by all means.
> has everything a car audio person would want.
> 
> Nice find .


Yep a must try! Maybe next car, if I take the older one I'm thinking of.
In the actual one I think I'll loose too much width.

Here's another one, found out following a link from Raimonds yesterday:
Building a Better Coax | Fulcrum Acoustic


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## oabeieo

Elgrosso said:


> Yep a must try! Maybe next car, if I take the older one I'm thinking of.
> In the actual one I think I'll loose too much width.
> 
> Here's another one, found out following a link from Raimonds yesterday:
> Building a Better Coax | Fulcrum Acoustic



Yeah but it's twelve inches! 

Might be ok for you lol a bit big for me ....hehehehe 



I need to find a good .....I mean very good HE 4" or 3" speakers 

I was fiddling with some LE small 3" speakers and it seems small drivers make the stage a lot wider when mounted up high. (Beamwidth??) 

so I want to try something different. But I need a recommendation on a good small loudspeaker that can be crossed at 200hz (BW) or 130hz (LR) 

Or a pair of solid 100db 2" drivers would be good also. 

Anything ring a bell ?


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## bassfromspace

A 4" coax with horn was linked earlier in the thread.


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## Patrick Bateman

oabeieo said:


> Yeah but it's twelve inches!
> 
> Might be ok for you lol a bit big for me ....hehehehe
> 
> 
> 
> I need to find a good .....I mean very good HE 4" or 3" speakers
> 
> I was fiddling with some LE small 3" speakers and it seems small drivers make the stage a lot wider when mounted up high. (Beamwidth??)
> 
> so I want to try something different. But I need a recommendation on a good small loudspeaker that can be crossed at 200hz (BW) or 130hz (LR)
> 
> Or a pair of solid 100db 2" drivers would be good also.
> 
> Anything ring a bell ?


Yep, that's beamwidth. What's happening is that the 3" driver goes omnipolar at 4500Hz, so you get a lot of energy radiated towards the windshield and the windows, and those secondary reflections make everything sound more spacious.

If you really want to go crazy with this, go listen to some of the Bose "direct/reflecting" speakers. I know Bose is a dirty word on audio forums, but their science isn't wrong. A clone of a Bose speaker beat the Linkwitz speaker in a blind test. The designer of that speaker has largely quit all audio forums, after spending the better part of the 90s trying to convince everyone that Bose had some good ideas:

https://www.google.com/search?q=gary+eickmeier+rec.audio.high-end

_"There are basically two "camps" or theories of speaker design and how stereo should work. Most are in the direct sound camp, the "accuracy" theory of getting the sound that went into the microphones as directly and purely to your ears as possible. Under this banner, the search for better reproduction has been a search for greater and greater accuracy.

Sounds pretty good doesn't it? But if we are operating on the wrong model, or theory of how stereo works, then we have been working without a stereo theory for the last 75 years or so. I presented a paper at the AES with a different theory to model the reproduction after, An Image Model Theory for Stereophonic Sound. The goal of good reproduction should be realism, not accuracy. This is not to throw the noble concept of accuracy out the window, but rather to ask accuracy of what compared to what?

I hope to show that it is an acoustical problem, not a direct transfer of a waveform from the microphones to your ears. What the reproduction should be modeling is the image model of live sound in a real room - the typical pattern of direct and reflected sounds that occurred live vs the patterns in your listening room are the correct accuracy of what compared to what that we should be after. I want to show that the role of the STEREO loudspeaker should not be as a direct radiator, but rather an Image Model Projector.

That paper was some 30 years ago, but it hasn't been until now that I could have some speakers made after my theory, and this month's meeting will be the public debut of them. You be the judge as to whether direct and reflected sound can be happy together in the pursuit that we all are after and love so much."
_


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## Patrick Bateman

Elgrosso said:


> Yep a must try! Maybe next car, if I take the older one I'm thinking of.
> In the actual one I think I'll loose too much width.
> 
> Here's another one, found out following a link from Raimonds yesterday:
> Building a Better Coax | Fulcrum Acoustic












Check out the polar response of various coaxes and you'll see the same problem over and over - there are serious issues with the polar response of the tweeter. This is basically the 'achilles heel' of a coax.

I still *like* coaxes, I have one at my desk here, and a Kef coax in my family room. But that problem is still there.










For comparison's sake, here's a cheap two way with a waveguide. (Behringer B2031P) Waveguides really smooth out that treble. The cone of a woofer doesn't make a very good waveguide.


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## Elgrosso

oabeieo said:


> Yeah but it's twelve inches!
> 
> Might be ok for you lol a bit big for me ....hehehehe
> 
> 
> 
> I need to find a good .....I mean very good HE 4" or 3" speakers
> 
> I was fiddling with some LE small 3" speakers and it seems small drivers make the stage a lot wider when mounted up high. (Beamwidth??)
> 
> so I want to try something different. But I need a recommendation on a good small loudspeaker that can be crossed at 200hz (BW) or 130hz (LR)
> 
> Or a pair of solid 100db 2" drivers would be good also.
> 
> Anything ring a bell ?


Ho man you're asking a lot for a 3" here!
Maybe a good 5" could do that, but not so low probably.
Here's one I'd like to try, but can't find it anywhere:
http://www.bmsspeakers.com/fileadmi...160_2011-04_neodymium_low_midrange_driver.pdf
Compact, powerfull, and should be good up to 3k

This one too, but bigger: FaitalPRO | LF Loudspeakers | M5N8-80

Or something like that if it fits:
Beyma Coaxial Speakers - Beyma 5CX200Nd 5" Neodymium coaxial speakers - Beyma 5CX200Nd 300 watt 5" coaxial speakers for all 2-way applications. Beyma 5CX200Nd 5" coxial speaker and other Beyma coaxial speakers here.

But if you want tiny maybe you should try the gb25, big power for super small.
Well IDK, I don't regret them much, sure width was better in pillars but I'm still in love with the horns


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## Elgrosso

Thanks for previous link PB, some more good readings.
I agree there's a sense of space that disappear a bit with the horns (in car), but the greater dynamic more than balance the loss for me.

Also maybe a good surround can give best of both world.
I wanted to try logic7 with my horns, but never took the time.




Patrick Bateman said:


> Check out the polar response of various coaxes and you'll see the same problem over and over - there are serious issues with the polar response of the tweeter. This is basically the 'achilles heel' of a coax.
> 
> I still *like* coaxes, I have one at my desk here, and a Kef coax in my family room. But that problem is still there.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> For comparison's sake, here's a cheap two way with a waveguide. (Behringer B2031P) Waveguides really smooth out that treble. The cone of a woofer doesn't make a very good waveguide.


Sure a good waveguide is better but within these space constrains it's not bad.
And it seems pretty constant, horizontally at least, so manageable with eq.
I need to try some, some time ago I had some kef but only listened to them in home, couldn't fit in the car.


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## oabeieo

Ha! 
Where do you find these gems

That 5ND BC looks excellent. But it's a 5" 

I need 3 or 4" max 

Although that 5 is awfully shallow. Dang that might work pretty good 

Okay how about if I can get down to 300HZ LR 
I could manage with that


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## SPLEclipse

You're going to have to go big to get the kind of efficiency and response you want.

I'm using the B&C 8pe21 (link to spec sheet below) in my upcoming build from ~300-~3khz, and it's an oversized 8" mid. The benefit, however, is a little over 4% n0, which is the highest I've ever seen for a midrange (and in the top 3 I've seen for _any_ direct radiator) Most of the speakers posted above have an n0 of around 1-1.5%, and most "typical" speakers are in the 0.5-1% range. It should be pretty feasible to make a 3" or 4" with a high reference efficiency, but you'd only see that north of 800hz-1khz with everything below dropping off quickly.

https://www.parts-express.com/pedocs/specs/294-652--8pe21-spec-sheet.pdf


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## oabeieo

SPLEclipse said:


> You're going to have to go big to get the kind of efficiency and response you want.
> 
> I'm using the B&C 8pe21 (link to spec sheet below) in my upcoming build from ~300-~3khz, and it's an oversized 8" mid. The benefit, however, is a little over 4% n0, which is the highest I've ever seen for a midrange (and in the top 3 I've seen for _any_ direct radiator) Most of the speakers posted above have an n0 of around 1-1.5%, and most "typical" speakers are in the 0.5-1% range. It should be pretty feasible to make a 3" or 4" with a high reference efficiency, but you'd only see that north of 800hz-1khz with everything below dropping off quickly.
> 
> https://www.parts-express.com/pedocs/specs/294-652--8pe21-spec-sheet.pdf



Where I want to put it I can't go bigger than maybe maybe a shallow 5


I think PBs theory on off axis reflection from a small drivers beamwidth making a wider stage might be questionable. 

I've been doing a lot of study's on reflections and refraction and diffraction are bad for good SQ and I don't think a reflection that close makes ambiance. Quite the contrary. 

I totally could be wrong too,

It seems a small driver up on top of a dash sounds wider , 1st guess , a uniform on/off axis responce. Mostly because of its wide dispersion at higher frequencies. 
So on and off axis FR and magnitude are more linear. 

But also......and this is my own thinking.....its size. It's relative size compared to the rest of the dash (car shapes and size). A smaller driver is easier to make sound farther away by shaping than a very large driver in close proximity. A lot less moving mass , so the point of origin is simply smaller , smaller point source means the environment is bigger relative to the speaker. 

Kinda like at 150' away from a outdoor arenas main hangs an 8" midrange in that PA stack at 150' away is the same relative size as a 3" speaker at 3'away (or whatever just an example) I'm fairly certain modulation would also play a role. 

It's a strange phenomenon, it's peaked my interest as of lately, maybe PB is right and the off axis HF that is more Omnidirectional from lack of bimming and reflections make it sound wider, but I'm my experience diffraction and refraction suck, now if it's just transfer that could work too....but I'm not convinced that's why it does that....


Btw nice 8"!  

i think PHL has a 4" , if I have to go LE maybe seal off the basket , bump the efficiency and dump power to it with an enclosure. Idk .....

Wanna find the right driver first


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## ca90ss

https://solen.ca/products/speakers/pro-speakers/pro-midranges/pr4neo8/


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## Elgrosso

I think I'm with you, PB is never wrong... but never totally right as well 
My 2 cts. Sure small drivers on dash can fit really far, since small with more homogenous spfr, and then sound wider (but maybe because they are placed at wider position at first) but also creates a bunch of issues.
Glass reflection, or opposite reflections and comb mess can help to create an ambiance for sure. But let's say poor man ambiance no? Like you said it's all in the time delay.

The bad thing with small drivers is that they're anemic.
I'm not picky about all this I just take my best compromise, it's all trade off (diyma copyright). But usually I prefer big sound, plentyfull and dynamic, over spatially pinpointed. Then once I have the dynamic I'll try to get the focus.
I can't see myself going back to small cones.

It's all personal of course, the way we enjoy music etc.
Well I just think we already have way too much reflections/diffractions in car.
Why not using horns/waveguide to try to control them a bit?
That's why I also want to try small coax on top, or in kicks, just for fun.
If they have a narrow dispersion.

Btw where do you want the 4 or 5" to fit?


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## oabeieo

ca90ss said:


> https://solen.ca/products/speakers/pro-speakers/pro-midranges/pr4neo8/


Oew la la ! Me likee....

Thank you for posting that. It looks perfect.


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## oabeieo

Elgrosso said:


> I think I'm with you, PB is never wrong... but never totally right as well
> My 2 cts. Sure small drivers on dash can fit really far, since small with more homogenous spfr, and then sound wider (but maybe because they are placed at wider position at first) but also creates a bunch of issues.
> Glass reflection, or opposite reflections and comb mess can help to create an ambiance for sure. But let's say poor man ambiance no? Like you said it's all in the time delay.
> 
> The bad thing with small drivers is that they're anemic.
> I'm not picky about all this I just take my best compromise, it's all trade off (diyma copyright). But usually I prefer big sound, plentyfull and dynamic, over spatially pinpointed. Then once I have the dynamic I'll try to get the focus.
> I can't see myself going back to small cones.
> 
> It's all personal of course, the way we enjoy music etc.
> Well I just think we already have way too much reflections/diffractions in car.
> Why not using horns/waveguide to try to control them a bit?
> That's why I also want to try small coax on top, or in kicks, just for fun.
> If they have a narrow dispersion.
> 
> Btw where do you want the 4 or 5" to fit?




Yeah , maybe it's just a terminology issue. 

"Ambience " is special reverberations. A reflection less than 28ms away would be the opposite. It would be like an extended (prolonged) narrow Q frequency band. It would be more like an irritating echo sound, not a pleasant sound. 


Also reverbant reflection in the upper dash and windshield sounds robotic and is not anything I would want to listen to lots of. 


So I think maybe PB is simply meaning even on/off axis responce and wide dispersion with reflective transfer that makes ambiance in the recording come out more. 


Reflections may have some good qualities, but almost always have something bad in it as well 

2c


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## Elgrosso

oabeieo said:


> Oew la la ! Me likee....
> 
> Thank you for posting that. It looks perfect.


Wow what a strange driver! 100db really?
What's the impact of the super low qts here, can it still work in a small sealed box without exploding?

I was looking at this one too, or the 3" version:
Single Product |
Seems really close to all faital/beyma etc or even gb25/40, just a little better sensitivity maybe with still good power.

Or bigger: http://www.zh-pro.com/d/5/phl_audio_950Nd.pdf
Did you see the new phl stuff? I thought phl was sold recently but didn't find much details.
Here's a nice list of the newest: ????,PHL Audio???????????????
And one that I'd really like to try: http://www.zh-pro.com/d/6.5/phl_audio_1660NdM-SQ2.pdf


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## Patrick Bateman

oabeieo said:


> Where I want to put it I can't go bigger than maybe maybe a shallow 5
> 
> 
> I think PBs theory on off axis reflection from a small drivers beamwidth making a wider stage might be questionable.
> 
> I've been doing a lot of study's on reflections and refraction and diffraction are bad for good SQ and I don't think a reflection that close makes ambiance. Quite the contrary.


I think there are basically two ways to attack the problem:

*method 1)* Minimize the energy that's radiated into the room/car. This approach requires waveguides, horns, arrays, dipoles or cardioids. Basically you use some type of device to put more energy towards the listener and less energy into the room/car. Examples of this are any speaker with a waveguide, as well as any speaker that uses an array to control directivity. (Dynaudio MTMs, the B&O 90, pretty much all JBL speakers, etc.)

*method 2)* Intentionally illuminate the surfaces of the room with sound energy. This approach requires arrays, omnipolar speakers, etc. The most obvious variant here is the Bose 801. Other examples are the MBL and Duvel omnipolars, the B&O omnis, and the Mirage bipoles (to an extent.)

So, they're two different approaches, and to me they both sound good subjectively.

They sound very different. For instance, a Danley Synergy Horn sounds like a big set of headphones. It definitely falls into the first category. The good thing about it is that it's very revealing of great recordings. The bad thing is that it's very revealing of bad recordings. When I had Synergy Horns in my car, one of my bummer realizations was that a lot of my music is recorded like crap and the Synergy Horn made these crappy recordings sound crappy. (I basically like EDM and a lot of old punk rock.)

The second approach produces a big stage. The additional reflections off the room add ambience and make everything sound "big." The downside is that it makes recordings sound very similar. IE, you could have a really good recording, and a really bad recording, and they'll both sound "big." I think this is part of the reason that you're always hearing the MBL omnipolar speakers demo'd with orchestral recordings. Orchestral recordings are supposed to sound big, so the omnipolar complements it well. I think that the added ambience can hurt the articulation of recordings.


I've long wondered why both approaches seem to sound so much better than conventional two way and three way loudspeakers. Here's my opinion:

With a conventional speaker, you basically have a device where it's both DIRECTIONAL and OMNIPOLAR but at different frequencies. For instance, a two way loudspeaker will be directional above about 2000Hz, and then it goes omni below that frequency. (This is because 2000hz is seven inches long, so when the wavelengths get long enough, they wrap around the baffle. The frequency that this happens will depend on the width of the baffle.)

In summary: I think that the fact that conventional speakers have two different radiation patterns creates a cognitive dissonance when you're listening to a recording. You have one set of frequencies that's beaming, you have another set that isn't. And I think that think are probably complicatd even further when you realize that the way that our hearing system works is fundamentally different ABOVE 1000hz.

So you're basically creating this audible dissonance, smack dab in the octave where our ears are particularly sensitive to aberrations.

Again, both solutions are admirable I think. If I had more money I'd have two different listening rooms, with two different type of speakers. 









For the past few years my reference speakers are these. They use a baffle that gets gradually wider, to combat the effect I described above. They also use felt to reduce diffraction. They're far from perfect, one of these days I build a proper set of synergy horns, but for the money I can't complain. I think they're better than 95% of the speakers that I've heard at a similar price.


----------



## Patrick Bateman

ca90ss said:


> https://solen.ca/products/speakers/pro-speakers/pro-midranges/pr4neo8/


I've been spending the better part of a decade looking for small woofers with a lot of motor force*, so when I see a spec sheet like this one I have to call "shenanigans" on it 

No offense, but a lot of these manufacturers like to lie on spec sheets.









I took their specs and plugged them into Hornresp for verification, and Hornresp indicates an efficiency of around 93dB.

I've seen a lot of Faital spec sheets where they exaggerate the efficiency by a couple dB, but methinks Max Fidelity is exaggerating the efficiency by around 6-7dB.


The very very very low QES is making this behave a lot like a compression driver, basically it's rolling off in the midrange. In an infinite baffle this driver rolls off around 600Hz.


By the way, this isn't a condemnation of the driver, it is VERY efficient! Just not as efficient as the spec sheet indicates, and I have a feeling that the QES figure is wildly off.

* Suitable midrange cone, for bandpass mid in Unity horn. - Page 5 - diyAudio

^^ Here's the thread that has all the collective wisdom about "high efficiency small midranges." After years of buying and evaluating drivers I'd probably say that the Celestion TF0410MR is probably the one to get if you want really REALLY high efficiency. It's a beast, an array of four will easily put out 100dB. The spec sheet says it has an efficiency of 90dB, but the frequency response measurement indicates it's higher than that. Kef and Celestion are the same company and I think their spec sheets are generally honest. It took us years of pleading to get someone to stock that driver, Celestion didn't want anything to do with the DIY crowd, and Loudspeakers Plus sells it now.


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## oabeieo

Patrick Bateman said:


> I've been spending the better part of a decade looking for small woofers with a lot of motor force*, so when I see a spec sheet like this one I have to call "shenanigans" on it
> 
> No offense, but a lot of these manufacturers like to lie on spec sheets.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I took their specs and plugged them into Hornresp for verification, and Hornresp indicates an efficiency of around 93dB.
> 
> I've seen a lot of Faital spec sheets where they exaggerate the efficiency by a couple dB, but methinks Max Fidelity is exaggerating the efficiency by around 6-7dB.
> 
> 
> The very very very low QES is making this behave a lot like a compression driver, basically it's rolling off in the midrange. In an infinite baffle this driver rolls off around 600Hz.
> 
> 
> By the way, this isn't a condemnation of the driver, it is VERY efficient! Just not as efficient as the spec sheet indicates, and I have a feeling that the QES figure is wildly off.
> 
> * Suitable midrange cone, for bandpass mid in Unity horn. - Page 5 - diyAudio
> 
> ^^ Here's the thread that has all the collective wisdom about "high efficiency small midranges." After years of buying and evaluating drivers I'd probably say that the Celestion TF0410MR is probably the one to get if you want really REALLY high efficiency. It's a beast, an array of four will easily put out 100dB. The spec sheet says it has an efficiency of 90dB, but the frequency response measurement indicates it's higher than that. Kef and Celestion are the same company and I think their spec sheets are generally honest. It took us years of pleading to get someone to stock that driver, Celestion didn't want anything to do with the DIY crowd, and Loudspeakers Plus sells it now.



Interesting.......


----------



## oabeieo

so PB? I have a ?????


I’m making a custom horn and putting this 4” mid under the horn in a sealed enclosure.
Do you think it would affect the horn by a lot of one of the horn mouths has some small perforations in it to allow the mid to play through? Most the mid will play through a hole but I want to perforate the custom horn mouth just a little bit to allow the mid to get through a bit more only on one side......


Should still work right? The mouth of horn loads it’s lowest frequencies which will be at crossover with mid. As long as levels are matched the perforations will be “invisible “ to the wave ....no????????

I can’t seem to add this in hornresp


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## Patrick Bateman

Though it's counter intuitive, here's how it works:

1) you would think that a sealed box would need to be perfectly sealed to work well, but it doesn't. A bunch of leaks can actually extend the F3 a little bit. That's an "aperiodic box."

2) you would think that a horn or ported box wouldn't be sensitive to leaks, since there's already a big hole in the box. (The mouth of the port or the mouth of the horn.) But the opposite is true; horns and ported boxes must be absolutely 100% airtight or you'll lose a ton of efficiency. This can be really maddening; back in 2010 I built a subwoofer horn that had a few tiny tiny leaks, we're talking about a millimeter or two in diameter. And those leaks reduced the output on the low end by about 6-10dB. Leaks in a horn are really really bad news.

Bose has a patent on a horn design where the mouth has a bunch of holes in it. I've never built one, but this design basically leverages the fact that *leaks in a horn are a bigger problem at the throat than at the mouth.* Basically air will take the path of least resistance, and air will quickly escape from leaks near the throat.


----------

