# In search of Bass in a car with not much Space



## Neil_J (Mar 2, 2011)

This is a writeup in the footsteps of lycan, Patrick Bateman, and so many others here at diyma, which intends to answer a specific question regarding sub-bass reproduction down to 20 Hz. How do you do it in a subcompact car, without taking up the entire cargo area? Everyone's seen that walled-off CRX stuffed with MTX jackhammers or MMATS juggernauts. Or that civic with some kind of tapped horn / t-line enclosure that hits like a pissed off Irishman. But what if you actually want to carry passengers, or maybe a bag of groceries? And what if you want to reproduce that low cleanly? What compromises can be made? 

Patrick Bateman started an excellent thread last year entitled, "BASS! How Low Can You Go?" (this thread is kind of trying to pick up where he left off), where he states: 


Patrick Bateman said:


> To sum it up, if you're speakers only go to 30hz, you're probably not missing a whole lot. Almost all the "bass" energy is in the octave from forty to eighty hertz. But there *are* a handful of tracks with synthetic bass lines that can only be heard properly if your speakers are flat to 20, or even 18hz. And yes, there's even bass down to 3hz.


Later, he posted:


Patrick Bateman said:


> I went to the Skrillex / Knife Party show in Vancouver last week, and that had to be, without a doubt, the most bass I've ever heard in my life. ... Anyways, Skrillex was doing thes same trick, but to *the whole damn venue.* I have no freaken idea how much power and subwoofers it takes to do that, but it was EPIC. Even if you hate Skrillex, hate Dubstep, and think that dance music is for douchebags, it was a neat trick.
> 
> When I was walking up to the venue you could see the walls flexing. That is an absurd amount of power. This is the kind of sound system that could probably damage a venue. I wouldn't be shocked to hear that it could actually crack a wall.
> 
> Also, I want to stress that it wasn't that the show was *loud*. It was that there was a level of subharmonic bass that I've never seen attempted. My home subs do 15hz, and I have a train that goes by my house twice a day. So I know the difference between a 40hz bassline and a 10hz roar. You hear one, and FEEL the other.


I saw Skrillex in December and can confirm everything Patrick says above. My pants legs were flapping from all the sub-bass, and could literally feel the floor shake. I'm pretty sure a few pair of britches got crapped in that night :surprised: If you haven't experienced such an event, get out of your mom's basement and do so, right now.. this post will be here when you get back. 

Love it or hate it, Dubstep and other fledgling electronic genres of music including Complextro, Moombahcore, and Glitchhop will make your system work harder than just about any other type of music out there. And IMO there is definitely some overlap between the Bass-Head and the SQ junkie.. They are not mutually exclusive. I will wholeheartedly agree that classic rock sounds like **** when the bass is boosted. _This is because the information was never there in the first place, and the tonality goes to hell when most "bass boost" circuits increase the bands from 40 to 100 Hz_. The genres mentioned above, however, were mastered to include sub- and infra-sonic bass down to DC, and don't need to be boosted at all. So the tonality is still there. Combined with a great three-way setup, and a rear-fill with Logic-7 style phase steering, these tracks sound positively amazing. A quick note about the rear fill.. There's a lot of out-of-phase content mixed into electronic tracks these days -- If you have Logic 7, listen to Rusko - Hold On (feat. Amber Coffman) (Sub Focus Remix), I can't imagine listening to it with only a front stage.

I am still somewhat of a newb, but here are the facts as I understand them (I am over-simplifying some of them for sake of brevity):

Hoffman's Iron Law states that the efficiency of a woofer system is directly proportional to its cabinet volume and the cube of its cutoff frequency (the lowest frequency it can usefully reproduce). The obvious implication is that to reduce the cutoff frequency by a factor of two, e.g. from 40 Hz to 20 Hz, while still retaining the same system efficiency, you need to increase the enclosure volume by 23=8 times! In other words, to reproduce ever lower frequencies at the same output level you need an extremely large box! -- quoted from a PB thread
More often than not, larger subwoofers reproduce lower frequencies more easily than smaller ones, while being more efficient. Consequently, larger drivers require a larger enclosures.
Ported enclosures sacrifice low end extension for efficiency higher in the passband. Most other exotic enclosure types work in the same way, and therefore aren't well suited to infra-sonic duties.
Making an enclosure smaller will reduce low-end frequency response.
Multiple subwoofers may offer better performance than a single subwoofer due to power compression. Everything else being equal, the multiple driver setup can play 3 dB louder with the same xmax.
Playing a a sub near or past its xmax will usually start to develop non-linearities that results in harmonic distortion. Some speaker models use shorting rings and other "tricks" to reduce non-linearities
Isobarik designs attempt to reduce non-linearities by using a set of matched drivers in push-pull configuration. I've heard mixed results on how well this actually works.
Sub-bass frequencies take considerable power (wattage) to reproduce. For a small car, class D amps are the way to go.
Cabin gain = free bass, and you get a lot of it in a subcompact. My R56 gets around 27 dB on the low end.
The short story is... Bass needs space. If you got the space, sub-bass is a piece of cake. If not, you will have to work around a serious set of compromises. Cabin gain is the only silver lining in an otherwise bleak and hazy future.


And to quickly dispel one of the most common myths. For anyone that says there's not a lot of content down at 20 Hz, I give you this, a random dubstep mix out of my iTunes library. It's a spectral plot of Excision Shambhala 2010 compilation, at around 1:19:20. 










Here's another track entitled Scatta by Skrillex and Foreign Beggars. I consider this to be a excellent sub-bass reference track. Definitely worth a listen if your system is up to it.









For comparison, here's Hank Williams Sr. singing Your Cheatin' Heart, recorded in 1952. There's literally nothing past 40 hz.









So in the case of the first two tracks (and many others), the information is there waiting to be played. For my next post, I will explain the current setup I'm using and the measurements that I came up with.


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## Neil_J (Mar 2, 2011)

A Mini Cooper S has *5.7* cubic feet of cargo space in the hatch area (compare that to *21* cubic feet in a 2012 Ford Explorer). Before I had a sub box, there was barely enough cargo room to get a load of groceries home without folding down the rear seat. Adding even a small box is a huge compromise with an area this small.

So, with 5.7 cubic feet to work with, that's:


Room for 1x of your average 12 in a false-floor configuration, with room for your groceries.. 
Barely enough room for two ported JL 12W7's, with no usable cargo room.
Room for multiple drivers in a false-floor configuration, as long as they're designed to work in a small enclosure space. 
No way in hell of getting any amount of 15's back there.
The last option is to keep the cargo area and put a set of 15's where the rear seats are. The vehicle is now a two-seater with the stock cargo area.. No way to fold the seats down or get anything big in the vehicle. Also, the middle of the car isn't a great spot for them (no corner loading)

After enlisting XtremeRevolution and Pete from PWK, I was presented with a false floor sealed enclosure, designed to fit four 8" drivers with 0.3 cubic feet per driver. I went with the Alpine SWR-843D's, as they were the forum boner at the time. 










We knew compromises had to be made... So it was decided that the Alpines could hit greater xmax cleanly (thanks to the shorting rings and other trickery), and by having four of them, the surface area to xmax ratio would be favorable. The main advantage is that the box is extremely small and flat, and hides in the floor of the hatch area. The main disadvantage, however, was the F3 rolloff at 53 Hz. The first thing I did after the box was built and wired was to take some RTA measurements to see how bad the harmonic distortion would be below the F3. Here are my results:









This was my test setup. Three of the four subwoofers wired, as I'm currently missing an amp. TrueRTA is running on the laptop, with the M-Audio MobilePre's Microphone #1 input connected to a Behringer ECM8000, and Line Output #1 connected directly to the amplifier subwoofer channels. I'm doing this outside the car, as I'm currently only interested in measuring harmonic distortion, and the rattles in my car would make that quite hard. 









100 Hz sinewave. Very clean. 









60 Hz sinewave (just above the F3 cutoff). Still very clean.









30 Hz sinewave. The harmonic distortion is very obvious on the RTA display, and is somewhat audible. The 2nd harmonic is 14 dB down.

No picture at 20 Hz. At low volumes, it's masked by the ambient noise, and a higher volumes it sounded like utter crap. Lots of flappy noises from the driver suspension. No need for an RTA plot when it's that obvious.

When placed in the car, the cabin gain helped tremendously. I didn't really come up with any decent RTA measurements, however. The subs seem capable of shaking the car to pieces, but will do so with rich harmonics that sound offensive to the ear. 

The jury is still out on this one. While this design meets three of my requirements (small, low, and loud), it doesn't meet my third (to do so cleanly). I'm tempted to temporarily mount the subs in Isobarik configuration to see if the non-linearities go away.


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## Brian Steele (Jun 1, 2007)

Neil_J said:


> 30 Hz sinewave. The harmonic distortion is very obvious on the RTA display, and is somewhat audible. The 2nd harmonic is 14 dB down.
> 
> No picture at 20 Hz. At low volumes, it's masked by the ambient noise, and a higher volumes it sounded like utter crap. Lots of flappy noises from the driver suspension. No need for an RTA plot when it's that obvious.


I'm curious - did you take the measurements at the same drive level from the amp, or did you take them at the same SPL level (which would mean that you increased the amp's output for the lower frequency measurements).

Note: A sine sweep measurement with HolmImpulse will give you a quick idea of the THD across the range of the subwoofer's response.




Neil_J said:


> I'm tempted to temporarily mount the subs in Isobarik configuration to see if the non-linearities go away.


The non-linearities in your measurements appear to be mostly odd-order. Isobaric mounting is likely not going to reduce this by much.


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## Danometal (Nov 16, 2009)

Interesting thread. I wanted to get low, so I went simple. I bought a JBL P1224, and built a big low tuned ported box (2.5 cubes @ 25 hz) wherein the port takes up a third of the box (port makes a 90 degree turn and then a 180 degree turn). The result is zero in car rolloff all the way down to 20 hz and below. If anything, it gains steam as it gets subsonic vs rolling off. Never been happier, and did it with a single 12.

Edit: I'm thinking it's possible to sell off 2 of the Alpines, and use the rest of the space for box and port, and tune stupid low and go as big as can fit, and thus low bass in minimal space.


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## extremepaint (Apr 23, 2011)

Im going to be watching this thread closley i love the shambala mixes and i want to make sure i can feel it in my truck and i have similar space requirments. However im looking at a single 10 but not sure if its gonna be enough


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## trumpet (Nov 14, 2010)

I like the idea of this thread and the Patrick Bateman thread you linked, which I've read. Hopefully these discussions can help people understand a) inaudible bass is out there in professional tracks but only if you're searching for it b) the compromises we all make become much more severe, if that word is appropriate, if we choose to emphasize the less audible bass frequencies.


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## fish (Jun 30, 2007)

Danometal said:


> Edit: I'm thinking it's possible to sell off 2 of the Alpines, and use the rest of the space for box and port, and tune stupid low and go as big as can fit, and thus low bass in minimal space.


I'm with Dan here. Before you give up on these subs you might as well spend another $50 & get a ported design from Pete. Maybe he can give you some input on if there will be much of a benefit going with 2 ported over the 4 sealed.


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## Neil_J (Mar 2, 2011)

Brian Steele said:


> I'm curious - did you take the measurements at the same drive level from the amp, or did you take them at the same SPL level (which would mean that you increased the amp's output for the lower frequency measurements).
> 
> Note: A sine sweep measurement with HolmImpulse will give you a quick idea of the THD across the range of the subwoofer's response.
> 
> ...


I was adjusting the gain on the MobilePre and was looking for the distortion to increase at higher levels. The screenshots were taken at approximately the same SPL levels. Probably not the most scientific method, admittedly. I'll be doing more measurements in the days/weeks to come. I will look into the Holmimpulse application, thanks for the advice.

As for the Isobaric configuration, I'm still reading some papers on it to dispel any myths I might have come across.. I will heed your advice in the meantime.


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## Neil_J (Mar 2, 2011)

Danometal said:


> Interesting thread. I wanted to get low, so I went simple. I bought a JBL P1224, and built a big low tuned ported box (2.5 cubes @ 25 hz) wherein the port takes up a third of the box (port makes a 90 degree turn and then a 180 degree turn). The result is zero in car rolloff all the way down to 20 hz and below. If anything, it gains steam as it gets subsonic vs rolling off. Never been happier, and did it with a single 12.


Interesting setup. I might have to model something like that myself. It would take up over half my cargo area, but might be worth it if it gets low cleanly.

And come to think of it, I haven't really tried researching what it takes to port a box that low.. Most of the vented enclosures I've dealt with are tuned much higher. I will make a note to look into this..


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## Neil_J (Mar 2, 2011)

fish said:


> I'm with Dan here. Before you give up on these subs you might as well spend another $50 & get a ported design from Pete. Maybe he can give you some input on if there will be much of a benefit going with 2 ported over the 4 sealed.


One of Pete's original comments was to try exactly this. I resisted at the time, since the subs had already been purchased, and because it would have taken more cargo space than the design I ended up with. In retrospect, I should have made a compromise on cargo space, and just listened to Pete :blush: It was naive to think that I could get that much bass out of something that small. Newb mistake I guess.

My next detailed post here will be an analysis of a dual ported enclosure with an extremely low tuning frequency, including calculated response curves including cabin gain. Pete's designs are great, but quite slow, so I'll be trying my hand at WinISD and some other tools / spreadsheets. From my sealed box measurements, I can gather that the harmonic distortion of the 843D's only gets bad at high xmax, so if I can keep that down on the ported box model, it should stay pretty clean. I'll also be auditioning some other sub models, including (for kicks and giggles), the new HAT I8SW / I10SW. Likely not a bass monster, but worth throwing in for good measures.


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## trojan fan (Nov 4, 2007)

Danometal said:


> I'm thinking it's possible to sell off 2 of the Alpines, and use the rest of the space for box and port, .


x2...that's exactly what i was thinking


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## Danometal (Nov 16, 2009)

Neil_J said:


> Interesting setup. I might have to model something like that myself. It would take up over half my cargo area, but might be worth it if it gets low cleanly.
> 
> And come to think of it, I haven't really tried researching what it takes to port a box that low.. Most of the vented enclosures I've dealt with are tuned much higher. I will make a note to look into this..


Yea, I have to stuff groceries around the sides of my box, as I intended for the cone and the port opening to only be about port width or so from the back of the trunk lid (to avoid any wave cancellation), so not much useable trunk space. 

If, in your car, you would be willing to take your box to just under the rear window line (with a stealth cover), you could do nearly anything you want. 

My first ported box was 4 cubes @ 36 hz for a Digital Designs 1515 sub. I despised it so bad I just grumbled every time I got in the car. Kinda glad I toasted it trying to force it to play anything lower than 30 hz. Look on caraudio.com. 99% of the ported sub stage guys there are tuned to like 32-38 hz. That creates a hideous peak around 45-55 hz, and the subsonics sound like a box fan. No thanks. Not even a 30 hz tune sounds good to my ears. That still creates a peak in the wrong place so as to make you think your box won't hit the higher bass frequencies.

But... when you drop your tuning down to 23-26 hz, something magical happens, and you get it all - tight SQ like a sealed box, but without the high F3, unreal subsonic response, no need for a SSF, and effortless, efficient output from below the threshold of human hearing up to wherever your particular sub likes its LPF to be. I reject all these claims that low tuned boxes need to be low passed at like 50 hz or whatever. Mine is crossed at 110.

Bad news is you might have to load groceries in the back seat lol


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## Danometal (Nov 16, 2009)

Neil_J said:


> One of Pete's original comments was to try exactly this. I resisted at the time, since the subs had already been purchased, and because it would have taken more cargo space than the design I ended up with. In retrospect, I should have made a compromise on cargo space, and just listened to Pete :blush: It was naive to think that I could get that much bass out of something that small. Newb mistake I guess.
> 
> My next detailed post here will be an analysis of a dual ported enclosure with an extremely low tuning frequency, including calculated response curves including cabin gain. Pete's designs are great, but quite slow, so I'll be trying my hand at WinISD and some other tools / spreadsheets. From my sealed box measurements, I can gather that the harmonic distortion of the 843D's only gets bad at high xmax, so if I can keep that down on the ported box model, it should stay pretty clean. I'll also be auditioning some other sub models, including (for kicks and giggles), the new HAT I8SW / I10SW. Likely not a bass monster, but worth throwing in for good measures.


One thing that converted me to preferring a single sub ported from a past of always going multiple sealed is that, no matter how many sealed subs you add to increase the first octave response, the actual response CURVE stays the same. Basically, I wasn't satisfied at the prospect of having to cut a bunch of mid to high level sub bass (45ish - 80ish hz) just to match the first octave response, even considering the general cabin gain vs. rolloff balancing act. I like to roll down and open every window I got in the the summer months, so there goes most of my cabin gain to level things out. 

But, dang those groceries...


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## Neil_J (Mar 2, 2011)

Danometal said:


> If, in your car, you would be willing to take your box to just under the rear window line (with a stealth cover), you could do nearly anything you want.


Not sure exactly what you mean by placing the box under the rear window line… That is assuming up-firing drivers and up-firing port? I'm pretty ignorant with ported boxed, what exactly would that do?



Danometal said:


> But... when you drop your tuning down to 23-26 hz, something magical happens, and you get it all - tight SQ like a sealed box, but without the high F3, unreal subsonic response, no need for a SSF, and effortless, efficient output from below the threshold of human hearing up to wherever your particular sub likes its LPF to be. I reject all these claims that low tuned boxes need to be low passed at like 50 hz or whatever. Mine is crossed at 110.
> 
> Bad news is you might have to load groceries in the back seat lol


Exactly… Bass is easy to get if you have the space for it! That was the whole purpose of this thread: Where is the compromise point between flat output to the lowest octave, and smallest enclosure possible, given all of the other factors? In a car analogy, if the standard large ported box is a Chevy 350, what I am after is something more like a Porsche 911 engine… Just as fast, half the weight, and tolerances are a lot tighter.



Danometal said:


> One thing that converted me to preferring a single sub ported from a past of always going multiple sealed is that, no matter how many sealed subs you add to increase the first octave response, the actual response CURVE stays the same. Basically, I wasn't satisfied at the prospect of having to cut a bunch of mid to high level sub bass (45ish - 80ish hz) just to match the first octave response, even considering the general cabin gain vs. rolloff balancing act. I like to roll down and open every window I got in the the summer months, so there goes most of my cabin gain to level things out.
> 
> But, dang those groceries...


That's a good point that I should have included in my first post. From the beginning, I always knew that my 4x sealed enclosure would need a lot of equalization, and I was okay with that, it was one of the compromises I was willing to make. As for rolling the windows down -- I don't think my town is ready for the level of filth that is Dubstep  I'd better keep them up!


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## Danometal (Nov 16, 2009)

Neil_J said:


> Not sure exactly what you mean by placing the box under the rear window line… That is assuming up-firing drivers and up-firing port? I'm pretty ignorant with ported boxed, what exactly would that do?


Oh, sorry. I meant to make your box height less high than the window line so as to make it less visible, but still be ample box.



Neil_J said:


> Exactly… Bass is easy to get if you have the space for it! That was the whole purpose of this thread: Where is the compromise point between flat output to the lowest octave, and smallest enclosure possible, given all of the other factors? In a car analogy, if the standard large ported box is a Chevy 350, what I am after is something more like a Porsche 911 engine… Just as fast, half the weight, and tolerances are a lot tighter.


Yea, sorry I got away from that a little on your thread. But, IMO, the way to get that is to be willing to sacrifice a little bit of the actual output and just scale down the setup, but you can effectively get your curve and response right in return. For example, 2 of your Alpines in as big and low tuned of a ported box as they can function well in vs. the same configuration for a pair of 12 inch Type Rs. So, like (guesssing) 1.5 cubes vs. 4.5 cubes.

Another compromise is to stay sealed, but use as large a sub as possible, with as low of a Fs as possible, in as big a sealed box (always smaller than ported) as possible so as to get as close as possible to a .7 to .8 Qtc. I did that with a RE Audio SE/x 15 (has a Fs of 22 hz) in a big sealed box. It caught some sick lows for sure.



Neil_J said:


> That's a good point that I should have included in my first post. From the beginning, I always knew that my 4x sealed enclosure would need a lot of equalization, and I was okay with that, it was one of the compromises I was willing to make. As for rolling the windows down -- I don't think my town is ready for the level of filth that is Dubstep  I'd better keep them up!


lol Filth? I admit I know nothing about dubstep. I have a low bass capable setup, yet I play anything from death metal to bluegrass on it. Got some old school bass albums for some roof flex when I'm in the mood lol. BTW, I'm fascinated with your RTA results. I've never used or even so much as seen one.


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## Neil_J (Mar 2, 2011)

Danometal said:


> Yea, sorry I got away from that a little on your thread.
> 
> lol Filth? I admit I know nothing about dubstep. I have a low bass capable setup, and I play anything from death metal to bluegrass on it. BTW, I'm fascinated with your RTA results. I've never used or even so much as seen one.


No worries. I've got a ton of informative stuff now to keep me busy for a few days. Thanks for the advice.

As for Dubstep.. if you can handle death metal, you may have an ear for it. And at the very least, it will exercise the low end of your system. A few tracks if you want to give it a listen:


First Of The Year (Equinox) - Skrillex [OFFICIAL] - YouTube
La Roux 'In For The Kill' - Skrillex remix - YouTube
SKRILLEX - Scary Monsters And Nice Sprites - YouTube
Butch Clancy - There's No I In Team, But There Is ME (Preview) - YouTube
(HQ) Cory Enemy & Dillon Francis - Ultra [Ultra Mixtape] - YouTube
Massive Attack - Paradise Circus (Zeds Dead Remix) - YouTube
Shirley Bassey - Diamonds are forever (Butch Clancy Dubstep Remix) - YouTube
Spitfire (Original Mix) - Porter Robinson (HD) - YouTube
Blue Foundation - Eyes On Fire (Zeds Dead Remix) - YouTube
Dubstep - Javandee - Final Escape - YouTube
Fytch & Captain Crunch 'Raindrops' ft Carmen Forbes - YouTube

That should be enough to wear out an alternator or two


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## fish (Jun 30, 2007)

Neil,

Another option to keep your box size down would be the use of passive radiators.


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## extremepaint (Apr 23, 2011)

Could someone explain more indepth on passive radiators and if one would work with a good 12? Say a w6/7 or the wgti mkII im loving this thread and i hope it will help me figure out my sub and box set up.


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## rodburner (Dec 13, 2011)

Tried some of the tunes you linked to and they sounded pretty dang good,even to my 56y/o ears.
And after reading this thread,it seems that I might be more satisfied with my SWR12/sealed or one of my unused RF HX2 10's in a ported box. It might need that 4" vc to play some of that stuff..


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## The Baron Groog (Mar 15, 2010)

Neil_J said:


> No worries. I've got a ton of informative stuff now to keep me busy for a few days. Thanks for the advice.
> 
> As for Dubstep.. if you can handle death metal, you may have an ear for it. And at the very least, it will exercise the low end of your system. A few tracks if you want to give it a listen:
> 
> ...


Some of my favourite tracks there

Have you read PB's thread "does anyone understand cabin gain". Some interesting points in it but the main ones (paraphrased) you should be thinking about:

Below FB of a vented enclosure cabin gain begins to drop off as the rear wave and front wave are basically acting against each other and cannot produce pressure.

Sealed boxes extend further, with the front and rear wave separated they no longer cancel each other below FB so maintain pressure.

So, either tune low with a big ported or forget ported and go sealed. I've fitted 2x SWR1243 into a 2003 Cooper S boot (pretty sure your boot is the same) in a sealed enclosure, that fitted underneath the factory parcel shelf-no room for shopping but you can't have both!


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## Danometal (Nov 16, 2009)

fish said:


> Neil,
> 
> Another option to keep your box size down would be the use of passive radiators.


^ This.


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## Danometal (Nov 16, 2009)

extremepaint said:


> Could someone explain more indepth on passive radiators and if one would work with a good 12? Say a w6/7 or the wgti mkII im loving this thread and i hope it will help me figure out my sub and box set up.


A good couple rules of thumb are: 

1). use double the cone area of your active sub for passive radiators, or at least a size larger (1 x 12 inch sub + 2 x 12 inch PRs, or 1 x 15 inch PR)

2). Provide the same net volume as is optimal with traditional ported (but you save all the space used by big long ports to tune so low)

3). I've read it lends good results to mount the PRs on the sides of the box perpendicular to the side your actual sub is mounted on.

I've always wanted to try a PR setup myself, but it costs more than just adding extra walls to a MDF box. I will one day for sure though.


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## cubdenno (Nov 10, 2007)

3 ways to get low. This is from the Home theater crowd but applicable)

Sealed: You get a high displacement linear sub (super woofer) place it in a sealed enclosure and power/EQ the bejeebus out of it. Think TC Sounds LMS 5400.

IB: Displacement Displacement Displacement. running 4 to infinity 18"+ woofers to keep output up and excursion low. Requires some EQ.



Large low tuned (LLT): Name is self explanatory. Obviously in your application, you have issues with the large. Add in the requirements for adequate port volume and that further compounds the issues.

or use a Passive radiator as mentioned above. 

Here are some links for an idea.

AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.

Got my PSI Passive Radiator -- What For ?! - SSA Car Audio Forum


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## cubdenno (Nov 10, 2007)

Also remember tht a lot of equipment will not play low. Not the subs but the amplifiers. Non defeatable high pass filters etc... Again something I have noticed in the HT circuit. Just something to be aware of.


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## adrenalinejunkie (Oct 17, 2010)

Neil_J said:


> No worries. I've got a ton of informative stuff now to keep me busy for a few days. Thanks for the advice.
> 
> As for Dubstep.. if you can handle death metal, you may have an ear for it. And at the very least, it will exercise the low end of your system. A few tracks if you want to give it a listen:
> 
> ...



Thanks for the traks, they're dope!


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## lionelc5 (Oct 31, 2011)

Replace the 8s with TC Epic 8s and cut the box size in half.........


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## cubdenno (Nov 10, 2007)

lionelc5 said:


> Replace the 8s with TC Epic 8s and cut the box size in half.........


While the Epic 8 requires a very small sealed enclosure, that does not answer any of the questions he is wanting answered or achieve any of the goals he is trying to achieve. So going out and spending more money on a different 8" subwoofer is bad advice. The performance will be within a few DB of each other. plus, I am not sure if the Alpine is designed to have lower Le induced distortion over the Epic but I believe it does. Xmax is close to one another I believe. And fitting the Epic 8's in a box half the size would require fiberglassing a new enclosure from the looks of his original for the Alpines.


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## trojan fan (Nov 4, 2007)

lionelc5 said:


> Replace the 8s with TC Epic 8s and cut the box size in half.........


He's looking for sound quality, not a one note wonder.....:laugh:


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## trojan fan (Nov 4, 2007)

Talk to Pete about a T-line design for 1 or 2 subs...I seen one of his video's with a 6" sub in a T-line enclosure...Wow!!!! you want to talk about some output from a single 6" driver


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## The Baron Groog (Mar 15, 2010)

If you've been reading Patrick's post you'll have probably noticed I bang on about my linkwitz transform enclosure I did for my 2003 Cooper S-works really well for me in my 1st "SQ" focused system. The cabin gain has added loads of bottom end and still works at motorway speeds. I do listen to dub-step, but haven't geared the system around it as it's not a major genre for me-however I have to say I'm pleasantly surprised with my results-LT was a total gamble for me, read about it, tried it - it works

On another forum I stumbled across this thread:Pros/Cons of large voice coils? - diyAudio

The Audiobahn subs this guy has picked up gave a nice bump in sub bass levels when modeled in BBpro using my car's cabin gain (as found in Andy W's HK graph) and compared to the Aliante-plus it handles around 4x the power. 6db louder at 350wrms 12dB up at 1200wrms 0.329cf box.

Below is the modeled output of the Audiobahn (orange trace) Vs the Aliante, a pic of my box in footwell and the double SWR box I did for a customer (budget restraints meant basic box!)


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## lionelc5 (Oct 31, 2011)

trojan fan said:


> He's looking for sound quality, not a one note wonder.....:laugh:


I dont know where you get a one hit wonder out of the TCs, I have a pair of the 10s in my vet and they have out performed any other 10 I have tried.


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## subwoofery (Nov 9, 2008)

trojan fan said:


> He's looking for sound quality, not a one note wonder.....:laugh:


Ok... Your comment and opinion is just plain unnecessary and useless since you've obviously never the Epic 8" or any TC Sounds based driver. And if you had ever heard one, I can assure you that your above post would have never existed. 
And I'm not talking about videos posted on youtube... 

I've used 2xAudiopulse Epic 8" in my car and can tell you they are not one note wonder drivers. 

Kelvin


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## Neil_J (Mar 2, 2011)

cubdenno said:


> Also remember tht a lot of equipment will not play low. Not the subs but the amplifiers. Non defeatable high pass filters etc... Again something I have noticed in the HT circuit. Just something to be aware of.


I'm armed to the teeth with test equipment... :rifle: No problem there


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## Neil_J (Mar 2, 2011)

cubdenno said:


> 3 ways to get low. This is from the Home theater crowd but applicable)
> 
> Sealed: You get a high displacement linear sub (super woofer) place it in a sealed enclosure and power/EQ the bejeebus out of it. Think TC Sounds LMS 5400.
> 
> ...


So since all of those home-theater methods would be insane and/or impossible in a subcompact (I'm not walling of my brand new car with 18's, buddy!), how would these look when scaled down to MINI proportions:


*Sealed single high displacement linear sub*: A single 12" or a JL 13.5" sealed would be the biggest that I could fit. I'm thinking something like a JL 13W7AE-D1.5 ?? Tons of power and eq. I could certainly model this up and add in the measured cabin gain... They recommend a 1.875 cu ft enclosure, which is about 150% larger than my current sealed enclosure.
*IB Displacement Displacement Displacement*: For a MINI Cooper? Inconceivable! The closes would be something like the array I have now, which is obviously not IB... but it is an array, and does have more displacement than a pair of 12's fwiw. Probably the least desirable option.
*Large low tuned (LLT)*: Again, I could fit as large as a single 13.5 if I give up most of my trunk space.. or something smaller if they model well. _This is where my money's at right now._ Either with conventional ports or (possibly) passive radiators if they'll fit and the geometry works out.


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## cubdenno (Nov 10, 2007)

I noticed your results with harmonic distortion. What level were you playing these? 1w/1m? some random voltage? Just curious.

Are you asking to much from this design? You know, them stupid laws of physics... And that idiot Hoffman...

4 subs (love the multiple motors) in a 1.3 cubic foot sealed enclosure is just not going to have ultra low output. 

Next question is, does the actual performance mirror within reason what you see in WinISD or some other box modeling software?

Reason I ask is if so, could you model your subs in a bigger enclosure? See what the modeled results are. We know that going bigger sealed, reduces power handling but lowers Fs. So is there a happy medium that allows you to have the enhanced low end while keeping the enclosure reasonable in size? Or are you just going to have to bight the bullet and go ported/PR?


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## Neil_J (Mar 2, 2011)

cubdenno said:


> I noticed your results with harmonic distortion. What level were you playing these? 1w/1m? some random voltage? Just curious.
> 
> Are you asking to much from this design? You know, them stupid laws of physics... And that idiot Hoffman...
> 
> ...


It was a somewhat unscientific test (I explained a bit on a previous post). However, I plan to spend at least few days truly characterizing them (wasn't able to do that Sunday evening, as it was the day before spring classes). I'm well aware that I'm asking a lot out of this box (or any other box for that matter). The idea is to squeeze everything out of it that I can, since I can't just factor in a bigger box and call it a day. That's where the measurement and planning will come in. Before it gets put into daily use and abuse, it will be fully measured and the subsonic filter and gains adjusted to make sure I don't let the magic blue smoke out.


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## cubdenno (Nov 10, 2007)

Neil_J said:


> So since all of those home-theater methods would be insane and/or impossible in a subcompact (I'm not walling of my brand new car with 18's, buddy!), how would these look when scaled down to MINI proportions:
> 
> 
> *Sealed single high displacement linear sub*: A single 12" or a JL 13.5" sealed would be the biggest that I could fit. I'm thinking something like a JL 13W7AE-D1.5 ?? Tons of power and eq. I could certainly model this up and add in the measured cabin gain... They recommend a 1.875 cu ft enclosure, which is about 150% larger than my current sealed enclosure.
> ...


Yeah, I had no doubt IB would be nixed... Sissy! 

Pfft and no wall.... My gosh what a scaredy cat. Think Columbus would have said "No wall." ? Hell no. He would have put in a wall and a half. In the wrong place of course but that is another story and irrelevent in regards to your sissy-ness.:laugh:


This is the woofer I would look at for the sealed 

TC Sounds LMS-R 12" DVC Subwoofer 293-658

~30mm 1 way xmax LMS coil 1.5-2 cu/ft sealed with EQ on the low end. And keep in mind realistic power levels. The lower you go per octave, to keep the same volume/output as the octave above equires 4X more travel. Which is why the LMS coil. Partsexpress so good shipping/return if it doesn't work for your application etc. 

I just hate to recommend spending more money an another woofer when you have 4 right there. Even running 2 with a PR design makes me wonder what the end result will be and if it will be enough. 30 hertz and up, I would say port it and get ready for VBA. But no. You want subsonics in a tiny space...


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## Danometal (Nov 16, 2009)

If you went for that 13W7 sealed you'll likely hit much lower than the 4 8s.

FWIW, I modeled the Alpine 8 in WinISD Beta last night because I was curious. It recommended ~ .8 @ 30 hz each sub, so 1.6 for a pair. It models flat to 30 like that actually. I personally wouldn't tune to 30 hz with a big sub, but flat to 30 hz from a little 8 incher is pretty sick.

That said, 30 hz isn't that low, IMO. The W7 will perform far lower than that, even sealed. It has lots of excursion, which is what you want in a sealed sub.


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## subwoofery (Nov 9, 2008)

Neil_J said:


> As mentioned in my other write-up thread, the box WILL hit down to 20 Hz. The displacement is there (more surface area than a pair of 12's), it's just a matter of getting there cleanly, and I'm pretty sure I'm being more picky than most people would be. I will be rocking the 4 8's for a few months, and heck, I might even fall in love with them. They do play AWFULLY clean above 45 Hz


Wondering if the harmonic distortion you're hearing is actually the box flexing. I ask coz with the power you have available (1200 watts), you're only reaching up to 12mm out of 14mm Xmax. 14mm is hit with more or less 1650 watts according to WinISD... 
Do you know about the Fathom from JL? It uses a box too small for the sub to perform optimally but uses EQ to boost the low end to where it should be. Seen measurements and they don't suffer from too much harmonic distortion even in the lowest octave... 

How is your enclosure braced? I ask coz you have a lot of cone area and not a lot of air inside the enclosure to move freely. 
Any wool or similar used inside your enclosure? 

Kelvin


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## Neil_J (Mar 2, 2011)

subwoofery said:


> Wondering if the harmonic distortion you're hearing is actually the box flexing. I ask coz with the power you have available (1200 watts), you're only reaching up to 12mm out of 14mm Xmax. 14mm is hit with more or less 1650 watts according to WinISD...
> Do you know about the Fathom from JL? It uses a box too small for the sub to perform optimally but uses EQ to boost the low end to where it should be. Seen measurements and they don't suffer from too much harmonic distortion even in the lowest octave...
> 
> How is your enclosure braced? I ask coz you have a lot of cone area and not a lot of air inside the enclosure to move freely.
> Any wool or similar used inside your enclosure?


I doubt it was the box flexing, but that would give me an excuse to break out the accelerometer and firmly attach it to the baffle (I'm not sure my hands are calibrated to know exactly how much is too much). It's built entirely from 3/4" MDF (including three airtight inner walls between drivers), glued and stapled I believe (no screws). 

They're stuffed, the first three chambers are filled with Stovetop Stuffing, and the fourth with creamy nougat 



And as far as my initial measurements go -- I think the peer review process has succeed here and invalidated my initial measurements... I will be retesting with a more controlled setup, and posting my results back here.


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## Brian Steele (Jun 1, 2007)

cubdenno said:


> 4 subs (love the multiple motors) in a 1.3 cubic foot sealed enclosure is just not going to have ultra low output.


It just occurred to me - did you try reversing two of the drivers and wiring them out of phase? This would convert your box to a dual push-pull arrangement, which should reduce even-order distortion. Hopefully those Alpine 8s don't suffer from motor noise, which will negate any reduction achieved by the push-pull arrangement.


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## trojan fan (Nov 4, 2007)

subwoofery said:


> Ok... Your comment and opinion is just plain unnecessary and useless since you've obviously never the Epic 8" or any TC Sounds based driver. And if you had ever heard one, I can assure you that your above post would have never existed.
> And I'm not talking about videos posted on youtube...
> 
> I've used 2xAudiopulse Epic 8" in my car and can tell you they are not one note wonder drivers.
> ...


If you are a fanboi of the epic 8's great, but there is no need to be rude to me

I listened to these exact subs on two different occasions and was not impressed with what was coming out of them, plus IMO the efficiency on them is terrible...if i was looking for some perceived speed and texture from a 8" this one would not be on my short list


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## trojan fan (Nov 4, 2007)

lionelc5 said:


> I dont know where you get a one hit wonder out of the TCs, I have a pair of the 10s in my vet and they have out performed any other 10 I have tried.


Great....I appreciate your opinion..:rockon:


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## subwoofery (Nov 9, 2008)

trojan fan said:


> If you are a fanboi of the epic 8's great, but there is no need to be rude to me
> Ok... I apologize for being rude. However the comment you've posted was really just asking for retaliation. You've been on the forum for a really long time and therefore should know that close to 50% of the members have either used a TC Sounds/Audiopulse product, used a product made by TC Sounds (Audiomobile, RF, Eclipse, etc...) or at least heard one. Really not a fanboi, it's just the first time EVER that I've read someone state that a TC Sounds product was a "one note wonder".
> I've read the 10 first pages of my search on google and none stated that TC Sounds makes a "one note wonder" subwoofer - quite the contrary actually: https://www.google.com/search?q=%22tc+sounds%22+%22one+note+wonder%22&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:frfficial&client=firefox-a
> Are you saying that all those people have crappy hearing?
> ...


Efficiency is terrible? I'm sure you're talking about sensitivity coz the efficiency in the bottom octaves is much better than most 8"s I've used. Do you know about "Hoffman's Iron Law" - I'm sure you do. 
In car audio, I'd rather use a low sensitivity driver. Why? Coz I want to keep my enclosure on the small side. I don't see an 8" that needs 1.5cuft sealed in order to work optimally being a big seller in the stores. 
Here's a thread that explains why low sensitivity is actually good for low freqs: Car Audio Classifieds 

Kelvin


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## The Baron Groog (Mar 15, 2010)

subwoofery said:


> ..
> Do you know about the Fathom from JL? It uses a box too small for the sub to perform optimally but uses EQ to boost the low end to where it should be. Seen measurements and they don't suffer from too much harmonic distortion even in the lowest octave...


^This is Linkwitz Transform that I've been harping on about, I use my car as the EQ (though have 16bands of EQ for further boosting, if required). Provided you have enough X-max and power you should get great results using this technique. My sub has 4mm X-max and 300wrms power handling, so the Alpines should whallop it.


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## lionelc5 (Oct 31, 2011)

To the OP, I did not mean for the suggestion of the TCs to get this thread off target.

My car,C6 Corvette, though not as small as yours is very space limited also. Especially if I want to still be able to store the targa top.

I used 2- TC Epic 10s because 
1)good reviews I had heard on them
2) relatively shallow mounting depth in relation to power handling
3) very small box needed

I am running 1,500 watts at them and they take it in stride (2 - HD 750/1s)

I suggested the 8 to you because in my opinion, you could power the 8s with the same power as I do my 10s and use 2- 8s instead of 4 of them.

This is only a hobby for me so there are far smarter people to listen to on here but maybe model them with your car and see?

Oh, and in my car the 10s get very low with alot of impact, I am thrilled with the outcome.

Thanks,
LionelC


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## cubdenno (Nov 10, 2007)

lionelc5 said:


> To the OP, I did not mean for the suggestion of the TCs to get this thread off target.
> 
> My car,C6 Corvette, though not as small as yours is very space limited also. Especially if I want to still be able to store the targa top.
> 
> ...


And I apologize if I came off sounding snarky as well. If you notice in my sig, I use a TC sub. Love them. It's just that in this case, swapping from 1 8" to an ultra small box 8" will not yield much if anything more in output. This is really a perfect example of how the enclosure dictates performance. It also really shows how in system design there are often compromises that have to be made. Or a hell of a lot of planning and trial and error.


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## The Baron Groog (Mar 15, 2010)

Brian Steele said:


> It just occurred to me - did you try reversing two of the drivers and wiring them out of phase? This would convert your box to a dual push-pull arrangement, which should reduce even-order distortion. Hopefully those Alpine 8s don't suffer from motor noise, which will negate any reduction achieved by the push-pull arrangement.


IS that what he wants? Distortion is a lot to do with how loud we perceive something to be-lots of people enjoy their sub's distortion as it makes their system seem louder than it really is-maybe he actually needs to add distortion

Seriously though, not experimented with it much myself, but PB was discussing on some thread or another that he and a friend were listening to some very low distortion speakers (his Sumos IIRC) and only realised that they had them too loud when they both realised they were shouting-the lack of distortion had fooled them into thinking the speakers were playing at a much lower level then they thought.

Also as each sub has it's own chamber you'd end up with a different Fb for the chambers where the drivers were reversed.


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## Neil_J (Mar 2, 2011)

The Baron Groog said:


> IS that what he wants? Distortion is a lot to do with how loud we perceive something to be-lots of people enjoy their sub's distortion as it makes their system seem louder than it really is-maybe he actually needs to add distortion
> 
> Seriously though, not experimented with it much myself, but PB was discussing on some thread or another that he and a friend were listening to some very low distortion speakers (his Sumos IIRC) and only realised that they had them too loud when they both realised they were shouting-the lack of distortion had fooled them into thinking the speakers were playing at a much lower level then they thought.


Good point.. Pete Kuliki has talked about that as well. Most electronic synth basslines have already been compressed and distorted and bitcrushed to hell and back... Therefore they will sound loud without requiring your sub stage to color it. So my preference is nice and clean all the way down to 20 at moderate volume levels. The ideal goal, although not really possible, is to keep xmax low, which keeps harmonic distortion low. However, You have the headroom to turn it up and get a bit of distortion, which could be useful for the 99% of passengers that start to complain when they hear it undistorted.


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## trojan fan (Nov 4, 2007)

subwoofery said:


> parameters that show how good it can work in small sealed enclosures... but you need power for it to really WANK.





subwoofery said:


> Efficiency is terrible? I'm sure you're talking about sensitivity coz the efficiency in the bottom octaves is much better than most 8"s I've used. Do you know about "Hoffman's Iron Law" -



IMO...the point i was trying to make is that these subs are inefficient at converting electrical energy into sound energy compared to other 8' woofers i like better

...and you seem to feel the same in a round about way


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## cubdenno (Nov 10, 2007)

trojan fan said:


> IMO...the point i was trying to make is that these subs are inefficient at converting electrical energy into sound energy compared to other 8' woofers i like better
> 
> ...and you seem to feel the same in a round about way


I would bet that these two subs (Alpine and TC) are not that different efficiency-wise/sensitivity in comparable enclosures. most same sized woofs are within a db or two of each other. (obviously pro-audio drivers are not to be included. But they come with trade offs of there own.)

Edit: I looked, the Alpine is rated as 83.5 and the TC is 81.2 as far as their sensitivity spec goes.

XMAX is a little different with the TC having 22 followed by the 14 for the Alpine.


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## subwoofery (Nov 9, 2008)

cubdenno said:


> And I apologize if I came off sounding snarky as well. If you notice in my sig, I use a TC sub. Love them. It's just that in this case, swapping from 1 8" to an ultra small box 8" will not yield much if anything more in output. This is really a perfect example of how the enclosure dictates performance. It also really shows how in system design there are often compromises that have to be made. Or a hell of a lot of planning and trial and error.


He might not have much more output but the F3 goes down (-10Hz) considerably with the Epic 8", the Q goes down (0.558 vs 0.85) helping in flattening his response and he'll keep Xmax in check ([email protected]: 12mm/14mm = 86%; [email protected]: 15mm/22mm = 68%) lowering harmonic distortion quite a bit too. 
Other than buying yet other subs, it's a win-win situation IMO 

Kelvin


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## Neil_J (Mar 2, 2011)

subwoofery said:


> He might not have much more output but the F3 goes down (-10Hz) considerably with the Epic 8", the Q goes down (0.558 vs 0.85) helping in flattening his response and he'll keep Xmax in check ([email protected]: 12mm/14mm = 86%; [email protected]: 15mm/22mm = 68%) lowering harmonic distortion quite a bit too.
> Other than buying yet other subs, it's a win-win situation IMO
> 
> Kelvin


Hmmm, does anyone have four of them laying around, that they could lend me? I could run a few tests and return them, bikinpunk style


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## cubdenno (Nov 10, 2007)

Telling you stop screwing around and wall in that puppy!!!:laugh:


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## lionelc5 (Oct 31, 2011)

I dont have any, but I wanted to buy a couple of the 8s to use as a "Stealth" sub underneath my couch. I was going to have someone model them to see what type of enclosure I should use.

If I have them I would send them to you to try out though......

LionelC


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## subwoofery (Nov 9, 2008)

trojan fan said:


> IMO...the point i was trying to make is that these subs are inefficient at converting electrical energy into sound energy compared to other 8' woofers i like better
> 
> ...and you seem to feel the same in a round about way


It's totally normal for the Epic to require lots of power, have you seen what the linear Xmax figure is? 22mm for an 8". The only comparable subwoofer in terms of VD is the JL 8W7 @ 19mm. I've played with the 8W7 extensively and it needs as much power as the Epic to output the same SPL @ low freqs. It has more energy above 50Hz due to the increased cone area. 
"compared to other 8" woofers you like better", JBL GTO8? Arc 8? ID8? Xmax figure are much lower on those and therefore will need less power to get it movin'... 

Kelvin 

PS: sorry to the OP for the OT


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## Neil_J (Mar 2, 2011)

subwoofery said:


> It's totally normal for the Epic to require lots of power, have you seen what the linear Xmax figure is? 22mm for an 8". The only comparable subwoofer in terms of VD is the JL 8W7 @ 19mm. I've played with the 8W7 extensively and it needs as much power as the Epic to output the same SPL @ low freqs. It has more energy above 50Hz due to the increased cone area.
> "compared to other 8" woofers you like better", JBL GTO8? Arc 8? ID8? Xmax figure are much lower on those and therefore will need less power to get it movin'...
> 
> Kelvin
> ...


No worries. So the the xmax is huge, but has anyone actually measured it for harmonic distortion? Most subwoofers are nasty things with tons of non-linearities, which was what got me so happy about the Alpine type R's.


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## trojan fan (Nov 4, 2007)

Neil_J said:


> No worries. So the the xmax is huge, but has anyone actually measured it for harmonic distortion? Most subwoofers are nasty things with tons of non-linearities, which was what got me so happy about the Alpine type R's.


Instead of going out and buying new subs(epic8"} you need to try a pair of your Alpines in a ported enclosure

It sounds like you are staring to get a little spun ....hang in there


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## Neil_J (Mar 2, 2011)

trojan fan said:


> Instead of going out and buying new subs(epic8"} you need to try a pair of your Alpines in a ported enclosure
> 
> It sounds like you are staring to get a little spun ....hang in there


Yes, that's still the plan  First I want to go back and re-test the THD of the the current box, and then start modeling some low tuned ported enclosures. But it will be at least a month or two before I have the resources and time to have a second enclosure built (if I get Pete involved again, it may be even longer). In the meantime, I will have a full fledged testing rig as of Wednesday when my power 830W supply shows up. Throwing another set of 8's in the current enclosure would be a piece of cake. Logistics ftw


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## trojan fan (Nov 4, 2007)

subwoofery said:


> It's totally normal for the Epic to require lots of power, have you seen what the linear Xmax figure is? 22mm for an 8". The only comparable subwoofer in terms of VD is the JL 8W7 @ 19mm. I've played with the 8W7 extensively and it needs as much power as the Epic to output the same SPL @ low freqs. It has more energy above 50Hz due to the increased cone area.
> "compared to other 8" woofers you like better", JBL GTO8? Arc 8? ID8? Xmax figure are much lower on those and therefore will need less power to get it movin'...
> 
> Kelvin
> ...


 going out of xmax does not add distortion in real world situations, when using well engineered woofers. running out of amp headroom makes this distortion, not exceeding xmax. exceeding xlim will produce distortion. going 3-5mm over a 15mm xmax still means a driver in a enclosure will go lower or louder or both, and i dont think the negative effects are anywhere near what most people go on about.


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## trojan fan (Nov 4, 2007)

Neil_J said:


> Yes, that's still the plan  First I want to go back and re-test the THD of the the current box, and then start modeling some low tuned ported enclosures. But it will be at least a month or two before I have the resources and time to have a second enclosure built (if I get Pete involved again, it may be even longer). In the meantime, I will have a full fledged testing rig as of Wednesday when my power 830W supply shows up. Throwing another set of 8's in the current enclosure would be a piece of cake. Logistics ftw


Try shooting Jim Walter a PM and get his opinion on your situation....good luck


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## lionelc5 (Oct 31, 2011)

So your current box is 0.3 cubic feet per sub, or 1.2 total. You could use 2 10s if you have the depth?

Here are some models using .65 per sub and my car, just for referance...





If you notice they barely exceed X-Max at 750W at 25hz. (Thays why I chose the HD 750s)
Qtc is at .65


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## lionelc5 (Oct 31, 2011)

Im not trying to "sell" you on the TCs. Its just an option. You could just put a new face on the box you already have for 2 10s instead of 4 8s.

Too bad your so far away, this kina stuff is best decided in the garage listening to the cars while drinking a few beers....


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## cubdenno (Nov 10, 2007)

lionelc5 said:


> Im not trying to "sell" you on the TCs. Its just an option. You could just put a new face on the box you already have for 2 10s instead of 4 8s.
> 
> *Too bad your so far away, this kina stuff is best decided in the garage listening to the cars while drinking a few beers*....


Truth!!!


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## Neil_J (Mar 2, 2011)

trojan fan said:


> going out of xmax does not add distortion in real world situations, when using well engineered woofers. running out of amp headroom makes this distortion, not exceeding xmax. exceeding xlim will produce distortion. going 3-5mm over a 15mm xmax still means a driver in a enclosure will go lower or louder or both, and i dont think the negative effects are anywhere near what most people go on about.


I don't know if I buy that... Look at the klippel graph below (or any klippel for that matter), asymmetries happen as excursion increases... some more than others. The Alpine SWR-843D in question lists its 10mm xmax "at 10% distortion". That would clearly explain my third RTA graph. Not sure if it fits your category of a well engineered woofer. It has shorting rings and all that good stuff.

YMMV I guess... subwoofer-generated harmonic distortion does one thing well, it gives away the position of the subwoofer. The sub frequencies may not be localizable, but the higher harmonics are. They will pull your front stage towards the back of your car.


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## trojan fan (Nov 4, 2007)

Neil_J said:


> I don't know if I buy that... Look at the klippel graph below (or any klippel for that matter), asymmetries happen as excursion increases... some more than others. The Alpine SWR-843D in question lists its 10mm xmax "at 10% distortion". That would clearly explain my third RTA graph. Not sure if it fits your category of a well engineered woofer. It has shorting rings and all that good stuff.
> 
> YMMV I guess... subwoofer-generated harmonic distortion does one thing well, it gives away the position of the subwoofer. The sub frequencies may not be localizable, but the higher harmonics are. They will pull your front stage towards the back of your car.


Dude, not to be rude but you are getting all caught up in all this technical stuff and you're on information overload....let your ears decide what works for you........better yet see what happens when you're driving 60 mph down the road

BTW i'm talking about in the car ...not graphs produced from a microphone


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## Neil_J (Mar 2, 2011)

trojan fan said:


> Dude, not to be rude but you are getting all caught up in all this technical stuff and you're on information overload....let your ears decide what works for you........better yet see what happens when you're driving 60 mph down the road


I haven't lost the forest for the trees, dude. I work in test and measurement and like to test and measure things. So if that's all the contribution you're going to make, the unsubcribe button is that way ^^^^^


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## chad (Jun 30, 2005)

Neil_J said:


> I saw Skrillex in December and can confirm everything Patrick says above. My pants legs were flapping from all the sub-bass, and could literally feel the floor shake. I'm pretty sure a few pair of britches got crapped in that night :surprised: If you haven't experienced such an event, get out of your mom's basement and do so, right now.. this post will be here when you get back.
> 
> Love it or hate it, Dubstep and other fledgling electronic genres of music including Complextro, Moombahcore, and Glitchhop will make your system work harder than just about any other type of music out there. And IMO there is definitely some overlap between the Bass-Head and the SQ junkie.. They are not mutually exclusive. I will wholeheartedly agree that classic rock sounds like **** when the bass is boosted. _This is because the information was never there in the first place, and the tonality goes to hell when most "bass boost" circuits increase the bands from 40 to 100 Hz_. The genres mentioned above, however, were mastered to include sub- and infra-sonic bass down to DC, and don't need to be boosted at all. So the tonality is still there. Combined with a great three-way setup, and a rear-fill with Logic-7 style phase steering, these tracks sound positively amazing. A quick note about the rear fill.. There's a lot of out-of-phase content mixed into electronic tracks these days -- If you have Logic 7, listen to Rusko - Hold On (feat. Amber Coffman) (Sub Focus Remix), I can't imagine listening to it with only a front stage.



I'd highly recommend looking into the big bass pro subs and note how low they really go... You maybe shocked, it' not that low. and the ones that do go low you may note that you need a metric ****load of them. There's not much of a transfer function is a 15,000 seat shed.


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## Neil_J (Mar 2, 2011)

chad said:


> I'd highly recommend looking into the big bass pro subs and note how low they really go... You maybe shocked, it' not that low. and the ones that do go low you may note that you need a metric ****load of them. There's not much of a transfer function is a 15,000 seat shed.


House of Blues Orlando is 2100 person and they were pulling hair tricks


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## chad (Jun 30, 2005)

should be easy to look up the system online and see if it correlates to what you saw.... I've taken lots of aux gear into HOB shows 

At 2K seats and under I'm happy when it tries to rip the door handle out of your hands in soundcheck. I call it headroom


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## subwoofery (Nov 9, 2008)

Neil_J said:


> No worries. So the the xmax is huge, but has anyone actually measured it for harmonic distortion? Most subwoofers are nasty things with tons of non-linearities, which was what got me so happy about the Alpine type R's.


Yep, I read about the 14mm Xmax figure @ 10% distortion for the Alpine. 
Here are specs for the TC Sounds Epic 8": 
TLS < 1% BL deviation : 14mm 
Geometric Stroke : 18.1mm - Millimeters, (voice coil - gap) / 2 
70% BL : 22.9 - Millimeters, BL is 0.7 original value (one way) 

I was really excited too when the Alpine 8" got released ; especially after seeing the Klippel test. However, plugging specs into WinISD told me that it was not necessary to replace the Epic 8" I had... 

Kelvin


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## subwoofery (Nov 9, 2008)

trojan fan said:


> *going out of xmax does not add distortion in real world situations*, when using well engineered woofers. running out of amp headroom makes this distortion, *not exceeding xmax*. exceeding xlim will produce distortion. going 3-5mm over a 15mm xmax still means a driver in a enclosure will go lower or louder or both, and i dont think the negative effects are anywhere near what most people go on about.


:worried2: 

Going over Xmax does not make distortion???  Only if you hit xlim? 
So if I understand your post right, a well engineered subwoofer, if kept under its max Xmax figure of 14mm (0mm to 14mm range) will only show let's say 1% distortion - from 14mm to xlim (19mm) will only show let's say 2% and as soon as you hit 20mm distortion increases to more than 10% all of a sudden? 
Do you think that what Alpine calls Xmax is in fact xlim? Coz from the manual: "_Xmax (One-Way Xmax @ 10% Distortion)_" 

I'm not gonna comment much on your post, I think I've read enough... 

FYI, one thing you have to remember, for subwoofer frequencies, 10% distortion is 20dB down from the fundamentals and 10% harmonics @ 20Hz is heard as loud as the fundamentals. 

Kelvin


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## subwoofery (Nov 9, 2008)

Neil_J said:


> I don't know if I buy that... Look at the klippel graph below (or any klippel for that matter), *asymmetries happen as excursion increases...* some more than others. The Alpine SWR-843D in question lists its 10mm xmax "at 10% distortion". That would clearly explain my third RTA graph. Not sure if it fits your category of a well engineered woofer. It has shorting rings and all that good stuff.
> 
> YMMV I guess... subwoofer-generated harmonic distortion does one thing well, it gives away the position of the subwoofer. The sub frequencies may not be localizable, but the higher harmonics are. They will pull your front stage towards the back of your car.


Exactly... 

Kelvin


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## trojan fan (Nov 4, 2007)

Neil_J said:


> YMMV I guess... subwoofer-generated harmonic distortion does one thing well, it gives away the position of the subwoofer. The sub frequencies may not be localizable, but the higher harmonics are. They will pull your front stage towards the back of your car. ]


Natural harmonics will also have the same effect


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## trojan fan (Nov 4, 2007)

subwoofery said:


> FYI, one thing you have to remember, for subwoofer frequencies, 10% distortion is 20dB down from the fundamentals and 10% harmonics @ 20Hz is heard as loud as the fundamentals.
> 
> Kelvin






Neil_J said:


> I don't know if I buy that... Look at the klippel graph below (or any klippel for that matter), asymmetries happen as excursion increases... some more than others. The Alpine SWR-843D in question lists its 10mm xmax "at 10% distortion". That would clearly explain my third RTA graph. Not sure if it fits your category of a well engineered woofer. It has shorting rings and all that good stuff.]


because the ears have a low sensitivity to bass from 40HZ to 20HZ a large majority of people can not perceive 10% harmonic distortion @ 20HZ

So wouldn't compression be a bigger issue when a speaker is driven past xmax


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## subwoofery (Nov 9, 2008)

trojan fan said:


> because the ears have a low sensitivity to bass from 40HZ to 20HZ a large majority of people can not perceive 10% harmonic distortion *@ 20HZ*
> 
> So wouldn't compression be a bigger issue when a speaker is driven past xmax


You know what harmonic distortion is, right? Harmonic distortion doesn't happen *@ 20Hz*... Harmonic means even and odd distortion - for a 20Hz tone, 2nd harmonic happens @ 40Hz and third @ 60Hz. 
10% harmonic happening @ 40Hz *CAN BE HEARD*. Not everyone can hear it but a trained ear that tries to listen for it will. I'm not making this up: Woofer measurements (info below graph #10) 

Saying that the majority of people can not perceive harmonic distortion of a 20Hz fundamental is just making a blank statement. 

Also in that paragraph, 3rd harmonic needs to be below 40dB (1%) in order to be less loud than the fundamentals: aka 20Hz. 

Regarding power compression, it's a problem even if you don't go pass Xmax. I've modelled the Epic 8" in a 0.4cuft ported enclosure tuned to 30Hz - I then apply a subsonic filter set to 30Hz 4th order - I can apply 1500 watts and still be under the max Xmax of 22mm. I've never tried but in the long run I can tell you that the 2" voice coil won't handle 1500 watts even if I keep max Xmax under check... 

I'm really not picking on you but either your statements are too broad or it's just not correct... I do have some arguments and proofs to back up my statements though. 

Kelvin 

PS: lots of info if you search a bit: https://www.google.com/search?hl=en...638l63452l0l63764l4l4l0l1l0l0l273l743l2-3l3l0 
I did in order to know what is the threshold of hearing for which frequency but that's another story...


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## vitvit (May 3, 2011)

trojan fan said:


> Natural harmonics will also have the same effect


Nope. "Natural" harmonics will not pass to your sub in the first place. (if they are out of band)


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## chad (Jun 30, 2005)

I cry ********, you need to do more research on the show you saw.... There's a whole world out there WAY-HAY more scientific than car audio.


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## ErinH (Feb 14, 2007)

trojan fan said:


> going out of xmax does not add distortion in real world situations, when using well engineered woofers. running out of amp headroom makes this distortion, not exceeding xmax. exceeding xlim will produce distortion. going 3-5mm over a 15mm xmax still means a driver in a enclosure will go lower or louder or both, and i dont think the negative effects are anywhere near what most people go on about.


First, define Xmax and xlim so we all are on the same page. 

Second, distortion doesn't only occur >ax or xlim (yes, I know you haven't defined ten yet).


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## Neil_J (Mar 2, 2011)

chad said:


> I cry ********, you need to do more research on the show you saw.... There's a whole world out there WAY-HAY more scientific than car audio.


What exactly are you calling ******** on, I will try to better explain what I stated above.


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## trojan fan (Nov 4, 2007)

bikinpunk said:


> First, define Xmax and xlim so we all are on the same page.
> 
> Second, distortion doesn't only occur >ax or xlim (yes, I know you haven't defined ten yet).


Xmax is the amount by which the voice coil can move in one direction without it leaving the magnetic zone

Xlim is the amount the voice coil can move in one direction before the back of the voice coil former slams into the magnet, which could cause permanent to the speaker and would also be it's excursion limit 




It's my understanding at a speaker can operate in this zone between Xmax and Xlim without risk of physical damage, but it's where distortion would	increase as excursion increases


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## subwoofery (Nov 9, 2008)

trojan fan said:


> Xmax is the amount by which the voice coil can move in one direction without it leaving the magnetic zone
> 
> Xlim is the amount the voice coil can move in one direction before the back of the voice coil former slams into the magnet, which could cause permanent to the speaker and would also be it's excursion limit
> 
> ...


Taken from here, right?  

Got that website bookmarked a long time ago. 

Kelvin


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## trojan fan (Nov 4, 2007)

subwoofery said:


> Taken from here, right?
> 
> Got that website bookmarked a long time ago.
> 
> Kelvin


I'm a missing something 

Why so vague....


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## Danometal (Nov 16, 2009)

Xlim = Xmech?


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## trojan fan (Nov 4, 2007)

Danometal said:


> Xlim = Xmech?


xmech is how far parts of the cone coil and suspension can travel before physical interference limits further excursion.


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## Danometal (Nov 16, 2009)

trojan fan said:


> xmech is how far parts of the cone coil and suspension can travel before physical interference limits further excursion.


I know exactly what kinda noise that makes! lol

"Whappappappappapp!! Oh crap!! Turn it down!!"


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## bird333 (May 28, 2008)

subwoofery said:


> Taken from here, right?
> 
> Got that website bookmarked a long time ago.
> 
> Kelvin


Link doesn't work.


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## trojan fan (Nov 4, 2007)

bird333 said:


> Link doesn't work.


I think something just might be missing there


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## subwoofery (Nov 9, 2008)

bird333 said:


> Link doesn't work.


Guess it just got deleted  

Kelvin


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## Neil_J (Mar 2, 2011)

This thread got forcefully derailed at about page 3, but I'll try to pull it back on-topic. I spent a few hours taking THD measurements with HolmImpulse today. I'm by no means an expert in this, and will likely didn't do everything perfect, but the data I ended up with seems to be within reason. 

Frequency response, with 1/3 octave smoothing:








Boomy, as expected for a small sealed enclosure. I will be low-passing them somewhere around 60-100 Hz, a subsonic filter at 25 Hz, and applying equalization as needed.

Distortion:








THD plot taken with two out of four SWR's playing in the 0.3 sealed box. This was done in my garage with a 60 amp 13.8 VDC power supply, with the doors open and garage door open in an attempt to eliminate room transfer function. Notice the second harmonic distortion that starts getting bad at 40 Hz.

Distortion, when converted from dB to %, is approximately: 
17% at 20 Hz
17% at 30 Hz
10% at 40 Hz
3% at 50 Hz
0.5% at 100 Hz

Legend is as follows:
Black is total THD
Red is the 2nd harmonic
Orange is the 3rd harmonic
Yellow is the 4th harmonic
Green is the 5th harmonic
Blue is the 6th harmonic
Gray is what HolmImpulse calls "Noise" under the THD drop-down box


At the advice of Brian Steele, I flipped the second sub around and re-measured:

















Using this method seems to give a 12% decrease in THD at 30 Hz, and almost 7% decrease at 40 Hz. It didn't help much at 20 Hz, however.
17% at 20 Hz
5% at 30 Hz
3% at 40 Hz
1% at 50 Hz
0.5% at 100 Hz

The distortion on the low end is actually slightly better than shown above, as the ECM8000 itself exhibits around 3% THD at 30 Hz, 115 dB SPL. The only way around this is to keep the volume down and try to manage the background noise, or buying a nicer (i.e. expensive) reference mic, likely in the 3-4 figure range. I definitely won't be trying the latter any time soon.


In conclusion, I may be able to live with the configuration above until I have time/money to drop on a low-tuned ported enclosure. Over the next month or so, I'll be listening to the enclosure in both normal and push-pull configurations in the car, and start choosing crossover frequencies and equalization points. When I finally do get the ported enclosure built, I'll post back with comparative THD plots to see how they stack up.


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## rodburner (Dec 13, 2011)

Neil_J said:


> a low-tuned ported enclosure.


How low is a low tuned ported box? I cobbled up a vented box on some box calc program today,supposedly tuned to 30hz and was advised by Mr. Walter to up that to at least 33hz. I whacked 10 inches off the port and still ended up at 32/33 because of the added net volume. Guess I'll just try it and see,since it's my first ported box build ever.


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## Brian Steele (Jun 1, 2007)

Neil_J said:


> At the advice of Brian Steele, I flipped the second sub around and re-measured


I see you connected up only two of the subs. Did you short the terminals for the other unconnected two subs while you were doing your measurements? If not, I suggest shorting them and trying your measurements again.


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## Neil_J (Mar 2, 2011)

Brian Steele said:


> I see you connected up only two of the subs. Did you short the terminals for the other unconnected two subs while you were doing your measurements? If not, I suggest shorting them and trying your measurements again.


No, but the four subs each have their own air-tight chamber. I could see shorting the other two out if the enclosure was just one big open space, but I was under the impression that I didn't have to bother if the enclosures are separate.


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## Brian Steele (Jun 1, 2007)

Neil_J said:


> No, but the four subs each have their own air-tight chamber. I could see shorting the other two out if the enclosure was just one big open space, but I was under the impression that I didn't have to bother if the enclosures are separate.


I think it's a good idea to short them when taking FR measurements. They will tend to vibrate at and around Fb, which could affect your measurements.


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## Neil_J (Mar 2, 2011)

Brian Steele said:


> I think it's a good idea to short them when taking FR measurements. They will tend to vibrate at and around Fb, which could affect your measurements.


My uneducated guess is that a slight change of gain my USB preamp, or a change in distance to the microphone stand, or even a difference in background noise from run to run would probably have more effect. Either way, I'll give it a shot Monday or so, and post back here with new plots if they're different.


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## EmptyKim (Jun 17, 2010)

I assume you've thought about this, but why not try two of the Alpine 8s in a ported box to see if you like the way it sounds. No need to buy new drivers, but throw together a new box, probably the same dimensions of the box you have for the four 8s.


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## Danometal (Nov 16, 2009)

rodburner said:


> How low is a low tuned ported box? I cobbled up a vented box on some box calc program today,supposedly tuned to 30hz and was advised by Mr. Walter to up that to at least 33hz. I whacked 10 inches off the port and still ended up at 32/33 because of the added net volume. Guess I'll just try it and see,since it's my first ported box build ever.


33 hz is not a low tune.


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## Danometal (Nov 16, 2009)

Neil_J, awesome results of the inverted sub to kill the second order distortion. Thanks for posting. I will consider that method in the event I ever run dual subs again.


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## rodburner (Dec 13, 2011)

Danometal said:


> 33 hz is not a low tune.


After reading page after page of opinion by smarter people than I,last night,I thought 30hz was a good starting point. But I followed the advice of Mr Walter nonetheless,and the results are pretty satisfying. My quicky test box has a little more bottom end output than the SWR 12,in a 1.07cf sealed box,plays just as loud,if not a little louder at some frequencies and is noticeably "quicker". 
It has a lot of weight to the range I'm sending it [30-63] and is very clean output. And it's only getting the 500w [for now] from my HD 900/5.
Gonna buy a couple more too and put one more in the ported box and the other in a tiny sealed,center console box for some crushing midbass.


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## The Baron Groog (Mar 15, 2010)

Brian Steele said:


> I think it's a good idea to short them when taking FR measurements. They will tend to vibrate at and around Fb, which could affect your measurements.


Wouldn't the differing box volume from inverted to "normal" make more of a difference - an extra 0.035cf air space within the enclosure is over 10% increase if built on the the 0.3cf recommendation.


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## Danometal (Nov 16, 2009)

rodburner said:


> After reading page after page of opinion by smarter people than I,last night,I thought 30hz was a good starting point. But I followed the advice of Mr Walter nonetheless,and the results are pretty satisfying. My quicky test box has a little more bottom end output than the SWR 12,in a 1.07cf sealed box,plays just as loud,if not a little louder at some frequencies and is noticeably "quicker".
> It has a lot of weight to the range I'm sending it [30-63] and is very clean output. And it's only getting the 500w [for now] from my HD 900/5.
> Gonna buy a couple more too and put one more in the ported box and the other in a tiny sealed,center console box for some crushing midbass.


Are you running the 8 SWR(s) like the OP? If so, 33 hz would be acceptable. However, I modeled it in WinISD, and it preferred a 30 hz tune with (IIRC) .75-.8 cubes each 8 incher for the flattest response.


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## Cancerkazoo (Jul 21, 2006)

Neil_J said:


> At the advice of Brian Steele, I flipped the second sub around and re-measured:


Is this layout acceptable for installation? If so why not 2 ISO pairs and go ported @ 30hz or > ?

you could keep the box very small then.
or

```
_____________
                     |    |  |    |
                    /\    |  |    /\
                  [|  |]        [|  |]
                    \/            \/
                     |____________|
```
Maybe ISO with a common port in this config if it will fit where you need it?


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## trojan fan (Nov 4, 2007)

Danometal said:


> Are you running the 8 SWR(s) like the OP? If so, 33 hz would be acceptable. However, I modeled it in WinISD, and it preferred a 30 hz tune with (IIRC) .75-.8 cubes each 8 incher for the flattest response.


 Tuning an enclosure to increase the bottom end will also decrease power handling and impact. you also need to be aware that below the port's tuning frequency the speaker becomes unloaded, and behaves like it would in free air. Which means frequency response drops rapidly beyond that point, more importantly, the driver's excursion increases greatly, to the point that the driver could sustain mechanical damage. This is why I would recommend the use of a subsonic filter


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## rodburner (Dec 13, 2011)

Danometal said:


> Are you running the 8 SWR(s) like the OP? If so, 33 hz would be acceptable. However, I modeled it in WinISD, and it preferred a 30 hz tune with (IIRC) .75-.8 cubes each 8 incher for the flattest response.


Yes,2, SWR 823's. But my enclosure is much smaller than that at 1.15 total net. If I had 1.5 to 1.6cf to spend,I would have ported the 12".lol
I can add at least a foot more port length inside the box and still keep the net at about 1cf.
And I'm using the 30hz-24db/oct ssf on the amp.


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## Blue Angel (Feb 21, 2012)

Any follow up to this? Interested to see the updated distortion plots with all subs powered and two inverted on the box.

In my experience, any sub enclosure that is not shorted out will resonate out of phase with another sound source. The total effect may be small in terms of affected output, but I have no idea how it would affect distortion plots.

I have played around with the SWR-823D in WinISD. The Alpine recommended enclosure seems a bit too small and tuned a bit too high for a flat response and good LF extention. IIRC, 25-26Hz tuning and a Vb of .65 ft3 worked rather well and would offer strong response into the mid 20's. Power handling at 14mm Xmax was right around 450-500W.


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## sqshoestring (Jun 19, 2007)

Great thread. Only way I know to get low in small space is spend a lot on a good high xmax, and power it up with EQ.
(or)
I've run IB in hatches a few times, just make a baffle for the top and figure out how to somewhat seal it. I load stuff under it and if I have to flip the whole thing with the seats.

Once I had a strange box that really worked well. It was a hatch I fit a 4cf in there with some old 10s in the rear side corners there was a space, it seemed to horn the bass out up to the hatch. The old 10s needed 2cf each to get low. So of course looking for more I put a 2.5" port in the center of the box (this was run on old school 2x60 and 2x75 12v rated amps). It helped a little, in retrospect likely too small a port. I had about 25% poly in the box all I had on hand. To the point I cut the port smaller and smaller and only then I got an improvement in low bass? I don't know why it seemed to unload the subs so they worked more like IB, almost like the port worked like an AP. I'm sure it was ported quite high, but I had more 30-35Hz I was happy. Way back then I was using formulas for porting in a speaker building book was all I had. Today I would go IB.

The issue with multiple small drivers is you typically get a higher Fs and less bottom from it, when you put multiple drivers together sure you get more but you get more of the same FR. To get bottom that is why I like larger drivers with lower Fs they seem to be more capable. The smaller multiple setup will hit hard in the FR it covers, just make sure that is where you want to be. If you want 30Hz and less the 15s tend to be ideal or a single 18 even. And under 35hz you really need to move some air, so big cone area or xmax makes it way easier to do.

Last you could consider going IB and venting to the outside, it depends on the car and would include chopping holes in it lol.

Given I tend to tune my subs, and when you go high xmax/power and EQ that does not matter much. 500rms is great on my current pair of 15s IB (cheap 15s lol) and is about as much power as I use on subs. They are very capable IMO down to 25hz at least.


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## sqshoestring (Jun 19, 2007)

I would also add, subs like the AEs are geared for more efficiency while getting low. If you are not out for massive output, and you can implement a sub like that which can reach a pretty high xmax on relatively low power...you will be ahead of the game. Many car subs are geared towards 30-80+Hz the way I see it, and big power numbers. Or like I did just go for more cone area to make up for it as my pyles don't have giant xmax likely don't have as good efficiency either...but run IB and pair of them works for me.


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## Danometal (Nov 16, 2009)

Super low bass capability is a priority for me, whatever the cost.


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## Neil_J (Mar 2, 2011)

I'll start playing with different sub box configurations and different subs in the next few months, in the meantime I have to finish fabrication on my amp rack. I tend to post back here when/if i get any new results.


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## chithead (Mar 19, 2008)

Subscribed. I just nabbed a 12W7 and am looking for the most bass in the smallest possible enclosure for my 2007 WRX Wagon.


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## captainscarlett (Mar 15, 2011)

People say (to the effect of) "Nothing really happens below 40Hz". I would say the vast majority of bass is in the 40-80 region, however I don't know if anyone else has noticed, but music seems to be dropping lower and lower from what it was 5, 10 years ago. Maybe I could throw in the issue of the recording itself. 

*Kaskade - I'll Never Dream* for some reason the beginning bass line rattles my car like nothing else.

Kaskade - I'll Never Dream - YouTube

With the little experience I do have, from prefabs to exotica, I've still yet to hear a 12 or 15 that sounds as sweet and tight as an 8.


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