# Shallow subs have poor low frequency extension...



## BEAVER

Opinions seem to differ here. Let's hear yours.


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## Victor_inox

JL shallow pretty awesome.


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## Hoye0017

Victor_inox said:


> JL shallow pretty awesome.



Agreed. Prefer the tw3's myself.


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## Ultimateherts

Yes the Stereo Integrity is quite awesome too


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## iasca judge

Also look at the illusion audio carbons. I promise you, my c12 has no issues playing extremely low (20-30hz range)


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## 2010hummerguy

My Stereo Integrity BM MKIII and MKIV both have very deep low end extension. Deeper than many conventional subs I've owned or heard.


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## lizardking

Alpine Type R does an outstanding job that would rival any.


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## 2010hummerguy

lizardking said:


> Alpine Type R does an outstanding job that would rival any.


These have very poor extension despite their hefty price tag. Very inefficient too.


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## SkizeR

Architect7 said:


> These have very poor extension despite their hefty price tag. Very inefficient too.


The ones I installed did fine


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## etroze

My shallow Skar VD10s do great. The only thing I am not impressed with is you still need a box that is .75^3 or bigger to get really low.


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## knever3

SkizeR said:


> The ones I installed did fine


I agree, but I don't have anything to measure it with except my ears though. Better than my MB Quart RSH 304 I had in there. Yes they are power hungry but a Zapco Studio 500 is doing nicely.

If I had known about the Studio integrity I might have tried it.


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## 2010hummerguy

SkizeR said:


> The ones I installed did fine


High Fs with those keeps them from digging very well below 40hz. Put an SI sub next to it and you'll wonder how you missed so much low content. Plus the SI will play much louder with half the power.  I had my SWR-T installed for less than a couple days, couldn't stand it.


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## TheDavel

Architect7 said:


> These have very poor extension despite their hefty price tag. Very inefficient too.


Not arguing but my experience was vastly different... the two I had in my tacoma did very well for shallow subs.


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## ErinH

I felt the same way Architect did. But, it was due to the enclosure. Which, in and of itself is the purpose of a shallow sub. Why buy a shallow sub if you need a large box. And in the size recommended by Alpine (0.35ft^3 net), my shallow 10" type-r sounded like a midbass than a _sub_-woofer. I had one installed in my wife's civic for some extra low end but it didn't do much below 50hz in that car. Even with cabin gain. Should have came as no surprise because the models of said enclosure indicated as much.


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## BEAVER

I appreciate all of the recommendations, but I was hoping for a technical discussion as to why (some) shallow subs suffer from poor LFE... And why others do not. I wanted to learn something here.


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## BEAVER

I have a Kenwood shallow 12. I hate it. It's boomy and had very little output below 50 Hz. Before wasting money on another shallow sub, I'm hoping to learn what to look for and make an educated decision. Otherwise, I'm gonna throw a bigass ported enclosure/sub in there just to be sure I have enough output down low... then EQ any excessive bloat... All of this would cause me a great deal of work and/or money, though.


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## sirbOOm

Stereo Integrity BK mkIV, as suggested above.

Shallow subs with poor low-end usually suffer from (1) poor excursion (especially in comparison to a similarly priced "regular" sub); (2) reduced/less effective mechanical control / reduced power handling; (3) placed in boxes too small relative to actual parameters so as to restrict their ability to reproduce low frequencies (limits of physics).

Making a shallow sub work is expensive and the technology is relatively newer and sometimes less effective. Cheaper ones are really only appropriate for rock music in most applications I've seen them. On the other side of the debate is the Stereo Integrity - an excellent flat sub suited for small enclosures. Somehow I will fit one of these into my truck. That said, the JL 13" flat is good, too - heard these in a "side of the trunk fiberglass enclosure" setup - got low but took some crafty EQ apparently. Illusion Audio's are good - heard a couple of those in an install once down in Florida. Image Dynamics IDQ flat subs are something I'd like to see someone try.


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## SkizeR

BEAVER said:


> I appreciate all of the recommendations, but I was hoping for a technical discussion as to why (some) shallow subs suffer from poor LFE... And why others do not. I wanted to learn something here.


because you cant have it all. hoffmans iron law. high sensitivity, plays low, doesnt require large box. pick 2

shallow subs just make this law stand out even more by being super limited on space (physical space, not box space)


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## TheDavel

SkizeR and sirbOOm pretty well covered it.


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## BEAVER

What I want to know is how the BM MKIV can work as well as a traditional sub... In half a cube... Why do the rules not apply to this sub?


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## SkizeR

BEAVER said:


> What I want to know is how the BM MKIV can work as well as a traditional sub... In half a cube... Why do the rules not apply to this sub?


like siriboom said, shallow subs are fairly new and technology and improvements for them are still advancing, as you can see with the stereo integrity sub. i havent really looked into it enough to know why it performs so well though.


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## ErinH

BEAVER said:


> What I want to know is how the BM MKIV can work as well as a traditional sub... In half a cube... Why do the rules not apply to this sub?


The rules apply... there's just a lot of variables when comparing shallow subs.

First, surface area. Some 10's have the surface area of most 8's. And on and on. Then there's how shallow it is. Some 'shallow' subs are under 3" mounting depth and others are closer to 3.5". So, compare apples to apples here. The SI is a 12" shallow sub at almost 3.5" mounting depth, IIRC. And it has a fair amount of linear excursion. If you compare it to an Alpine at 3.5" mounting depth and almost 14mm linear excursion (based on their supplied Bl data at 70% Bl for 20% THD), you see these two are similar here. Now, what about Fs, Vas, Qt*s*, efficiency and surface area? What about them is different. Which one plays more of a role (ie; if surface area is pretty close then toss that out). 

Hoffman's iron law pretty much tells you what you need to know. It could very well be that the SI strikes the balance better than the other options. Simple winISD models will typically tell you what you need to know.


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## ErinH

you want the "in a nutshell" reason shallow subs typically don't get as low as other options, all things essentially being equal? the depth itself. that limits excursion and (potentially) cooling of the VC (depending on the design). IMHO, of course.


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## alpinem

I am using two of these in my living room for theater use. They do a fantastic job and have no trouble getting into the 20s......

The Madisound Speaker Store


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## sirbOOm

And as you can see - they are more expensive! $295 each. G'damm!!!!


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## CrossFired

I still like the original shallow subs, Earthquake SWS. They got it correct from the start. I first installed a couple of EQ SWS 10's back in 03. At the time I was skeptical of the design, but I could find no other shallow subs, so I took a chance on the Earthquakes, and was amazed by there sound. Are there better shallow subs? Maybe, but I have not tried the Johnny come lately shallows, because the SWS work very well.


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## 2010hummerguy

BEAVER said:


> I appreciate all of the recommendations, but I was hoping for a technical discussion as to why (some) shallow subs suffer from poor LFE... And why others do not. I wanted to learn something here.


Low FS, good linearity (Bl stays linear through full excursion). Good excursion as well.



CrossFired said:


> I still like the original shallow subs, Earthquake SWS. They got it correct from the start. I first installed a couple of EQ SWS 10's back in 03. At the time I was skeptical of the design, but I could find no other shallow subs, so I took a chance on the Earthquakes, and was amazed by there sound. Are there better shallow subs? Maybe, but I have not tried the Johnny come lately shallows, because the SWS work very well.


My Earthquake SWS12X arrived last week and I was able to use it for a couple days before encountering an unrelated RCA issue. But for the couple days I did use it I was very impressed, definitely the 2nd best shallow sub I've ever used. It did not sound as good as an SI BM MKIV in a small box but in .7cuft. and 1cuft it was a monster with only 300 watts. It needed the extra volume to match the SI's extension and was not as low distortion (I was able to localize it better compared to the SI). But for $105 shipped it is hard to beat and definitely performed better than the Alpine Type R or JL Tw5v2 I have heard/used. Anyone on a budget looking for a shallow sub won't find better than the Earthquake


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## BEAVER

I appreciate all of the input, guys. Thanks a ton. Does anyone happen to have the rd parameters for the SI BM MKIV? I haven't been able to find them with a brief search. I need to look into the Earthquake, too.


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## Bigfx

Where did you get the earthquake from for 105$


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## 2010hummerguy

BEAVER said:


> I appreciate all of the input, guys. Thanks a ton. Does anyone happen to have the rd parameters for the SI BM MKIV? I haven't been able to find them with a brief search. I need to look into the Earthquake, too.


SI BM MKIV T/S specs (Nick may correct me since this is from the prototype thread here: http://stereointegrity.com/forums/si-products/1319-bm-mkiv-prototype-update-t-ss-inside.html):
Re: 6.26
Fs: 19 Hz
Qes: 0.54
Qms: 7.97
Qts: 0.50
Le: 3.97
Sd: 453.7 cm^2
Vas: 71.3 liters
BL: 19.9
Mms: 287.5
Xmax: 14mm
Xsus: 19mm
SPL: 82 dB (1W/1M)

Earthquake SWS12X specs (per this PDF...hard to find since it is not listed on the USA site: http://www.earthquakeeurope.com/Products/Car-Audio/Subwoofers/SWS/SWS-12X/Pdf/US/SWS_manual_US.pdf):
Re: 3.7
Fs: 24hz
Sd: 53msqM (530cm^2?)
BL: 10.642 (TM)
Qms: 3.56
Qes: .515
Qts: .45
SPL: 89.4db
Vas: 149.612 (liter)
Xmax: 31mm (one direction)



Bigfx said:


> Where did you get the earthquake from for 105$


Onlinecarstereo.com but big caveat emptor there...they shipped the SWS VERY fast so I became confident and ordered 3 PPI Atom amps from them. They sent me the wrong 4 channel and then told me the mono amps were shipping...then processing...then shipping...then backordered indefinitely. So I canceled my orders and I'll be buying those elsewhere. Call ahead to make sure they're in stock or buy somewhere else to avoid supporting those crooks.


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## rockford33

Sonic electronics sells the Earthquake subs also. I was set on the SI, but for a third of the price the earthquake may be a good bargain. Wish I could listen to either of them...


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## Bigfx

So quick question would you recommend this sub (earthquake) in a smallish enclosure I have a tundra crewmax max and have literally no room and all the other subs are really expensive...this would be ran off the bridged channels from my ppi 900.4


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## 2010hummerguy

The SI will be a better choice for a smaller enclosure. The Earthquake didn't like .5 cu. ft. very much. Though you could probably use its big xmax to add more low end eq but then you're facing distortion issues...I found that the harder I pushed the Earthquake beyond ~50% xmax, the less clean it sounded. And this was in a very well sealed box, no air leaks, etc.


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## Bigfx

Man no cheap alternatives..that si is really expensive. .some one told me hertz shallows weren't bad either? Anyone listen to those?


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## strakele

The problem with a lot of them is enclosure size. You see a shallow sub and you think small box. But when you actually model the specs, you find that, in almost all case, the shallow sub requires MORE airspace than it's full size counterpart. So when you put them in these tiny boxes that the manufacturers "recommend" you get the typical big hump at 40-50Hz and rapid roll off after that.

One of the only shallow subs I've ever seen that models well in a small box is the 8 ohm SB Acoustics SW26DAC76-8. .707 Qtc in like .28 cubic feet. On the other hand, I've modeled many many shallow subs and most want between 3 and 6 cubic feet - some even more.

The SI BM Mk4 models extremely well in 2.75 cubic feet. F3 is an amazing 27Hz. Reduce the enclosure to .5 cubic feet recommended, and you get a bump at 60Hz, increase the F3 to 48Hz, cut response at 20Hz by 8dB, and raise Qtc over 1.15. Obviously from user reviews, it still sounds good. Most shallow subs model much worse than this in small boxes. With a box that large, it reduces power handling to around 250W with a 20Hz high pass. In the .5 cubic foot box, it takes 650W with no high pass.

Most people probably don't bother trying, cause it kinda defeats the purpose, but I'd bet most shallow subs would sound just fine with good extension in a big box.


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## 2010hummerguy

Bigfx said:


> Man no cheap alternatives..that si is really expensive. .some one told me hertz shallows weren't bad either? Anyone listen to those?


I might have an MKIII for sale soon...selling my wife's Jeep and the next rig will be leased so no audio allowed. Or I'll stockpile it for another car someday lol.


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## Bigfx

Let me know!!


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## subwoofery

strakele said:


> The problem with a lot of them is enclosure size. You see a shallow sub and you think small box. But when you actually model the specs, you find that, in almost all case, the shallow sub requires MORE airspace than it's full size counterpart. So when you put them in these tiny boxes that the manufacturers "recommend" you get the typical big hump at 40-50Hz and rapid roll off after that.
> 
> One of the only shallow subs I've ever seen that models well in a small box is the 8 ohm SB Acoustics SW26DAC76-8. .707 Qtc in like .28 cubic feet. On the other hand, I've modeled many many shallow subs and most want between 3 and 6 cubic feet - some even more.
> 
> The SI BM Mk4 models extremely well in 2.75 cubic feet. F3 is an amazing 27Hz. Reduce the enclosure to .5 cubic feet recommended, and you get a bump at 60Hz, increase the F3 to 48Hz, cut response at 20Hz by 8dB, and raise Qtc over 1.15. Obviously from user reviews, it still sounds good. Most shallow subs model much worse than this in small boxes. With a box that large, it reduces power handling to around 250W with a 20Hz high pass. In the .5 cubic foot box, it takes 650W with no high pass.
> 
> Most people probably don't bother trying, cause it kinda defeats the purpose, but I'd bet most shallow subs would sound just fine with good extension in a big box.


Yup, the SW26DAC76 would be the only other shallow sub I would like to try. 
Have modelled quite a few and it's true that the SI doesn't model as well as a SW26DAC76 but it goes much much lower than everything out there... 
The other 2 subs that models well are the RE Audio SL (10" or 12") or the MTX Shallow series. 

Did model the Earthquake SWS and from what I remembered, it did not model well... 

The only shallow sub I did not model/compare is the Illusion Audio Carbon slim

Low FS (heavy cone) and High BL (strong motor) would be a requirement for a shallow subwoofer IN ORDER TO PLAY IN A SMALL BOX - problem with that is that it won't play very loud without dropping some power. Then you have a problem: cooling of the voice coil - shallow subwoofers don't have the necessary area to cool coz the coil is, well, short. 
So creating a good shallow sub is a science

Kelvin


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## Electrodynamic

I think this has been pretty well covered but you can not bend Hoffman's Iron Law. The BM mkIV has a very low inductance voice coil which gives it the nice effortlessly blending quality with your front stage. Add to the latter the 14mm of Xmax and you have a completely different shallow subwoofer than anything else out there. Are other drivers louder? Possibly. Do said drivers have higher distortion than the BM mkIV? Yes. 

Most of the shallow subs are designed with only one thing in mind and that one requirement is shallow mounting depth. The requirement to play low or sound clean was not in the cards when they designed the woofer. The neat feature of the BM mkIV is that it does play low...very low. In-car response is flat to 20 Hz and it keeps extending below that. Regarding Qtc and WinISD you should throw those figures out the window since you are installing your subwoofer system in a vehicle. I have made many many posts about this throughout the years but if, and only if, you are listening to your subwoofer system in an anechoic chamber you can take the Qtc and WinISD plots pretty accurately. But if you are installing the subwoofer system in a home those figures go out the window. Now place that subwoofer system in a tiny high-pressure car audio environment and you can throw those figures even further out the window. The BM mkIII and mkIV are not in a low Qtc alignment when installed in its proper 0.5 ft^3 enclosure yet you will not find a single user saying that they put it in a larger box and it sounded better. 0.5 ft^3 to 0.6 ft^3 is optimum for the BM mkIV woofer regardless of what a WinISD says. 

You have to ask yourself one question: Do you want nothing else than to be known for going "boom boom boom" down the road, or do you actually care about the quality of your sound reproduction? If you care about how it sounds the BM mkIV is for you because power is affordable these days and the BM mkIV does not _need_ a lot of power to perform at optimum. 300 watts is more than enough power for a single BM mkIV in 0.5 ft^3 sealed.

And as mentioned above, a BM mkIV in 0.5 ft^3 sealed is usually flat down to/below 20 Hz in a vehicle.


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## vette_werks

I run the earthquake sws 15; running a 15 was a must for me, as its my subwoofer preference. Idk how it does in limited space, but I run it in a fairly large sealed box and its lower extension is comparable to a regular sub in all honesty. The xmax is huge on this sub, at least for a shallow one, of nearly 3 inches. I bet in a small enclosure, its probably terrible, even if that's what it was primarily designed for. I noticed it does have an odd characteristic of localization when crossed over a little to high, its really happy at around 50hz but I am able to crossover at 40 with my front stage midbass now with a small slope. It really blends very nicely and no one can ever guess its a shallow mount when even when it was crossed at 63hz with an 18db slope. It hauls ass, and I wouldn't go for a traditional sub in any case. Hell I had to do a loading board to help quell the sub. Of course my car is small and a hatchback so its better suited for this setup. In a trunk setup, I think you could find its limitations compared to a traditional sub fairly easily when trying to push it.
I wish they made more of the 15 shallows, its lighter more efficient etc.


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## Electrodynamic

vette_werks said:


> I run the earthquake sws 15; running a 15 was a must for me, as its my subwoofer preference. Idk how it does in limited space, but I run it in a fairly large sealed box and its lower extension is comparable to a regular sub in all honesty. *The xmax is huge on this sub, at least for a shallow one, of nearly 3 inches.* I bet in a small enclosure, its probably terrible, even if that's what it was primarily designed for. I noticed it does have an odd characteristic of localization when crossed over a little to high, its really happy at around 50hz but I am able to crossover at 40 with my front stage midbass now with a small slope. It really blends very nicely and no one can ever guess its a shallow mount when even when it was crossed at 63hz with an 18db slope. It hauls ass, and I wouldn't go for a traditional sub in any case. Hell I had to do a loading board to help quell the sub. Of course my car is small and a hatchback so its better suited for this setup. In a trunk setup, I think you could find its limitations compared to a traditional sub fairly easily when trying to push it.
> I wish they made more of the 15 shallows, its lighter more efficient etc.


What data is available that can attest your claim of 75+mm of one-way linear excursion? Xmax is one-way linear excursion (70% BL previous, more accurate standards, or 82% via the newer standards). I don't care how deep the driver is, I want to see Klippel data for 75+mm of one-way linear excursion. 

I just did a quick search and found they spec the Xmax at 34mm one-direction, not 75mm. Even if you took it upon yourself to merge both forward and rearward you would end up with 68mm of total (rearward and forward) linear travel, not 75mm. 

Does Earthquake have any Klippel data to back up their Xmax claim on thier design? I'm curious because that's an awesome amount of linear stroke in such a shallow depth package.


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## 2010hummerguy

Electrodynamic said:


> What data is available that can attest your claim of 75+mm of one-way linear excursion? Xmax is one-way linear excursion (70% BL previous, more accurate standards, or 82% via the newer standards). I don't care how deep the driver is, I want to see Klippel data for 75+mm of one-way linear excursion.
> 
> I just did a quick search and found they spec the Xmax at 34mm one-direction, not 75mm. Even if you took it upon yourself to merge both forward and rearward you would end up with 68mm of total (rearward and forward) linear travel, not 75mm.
> 
> Does Earthquake have any Klippel data to back up their Xmax claim on thier design? I'm curious because that's an awesome amount of linear stroke in such a shallow depth package.


I am willing to send my SWS12X I bought for science to anyone to be Klippel tested.


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## vette_werks

Electrodynamic said:


> What data is available that can attest your claim of 75+mm of one-way linear excursion? Xmax is one-way linear excursion (70% BL previous, more accurate standards, or 82% via the newer standards). I don't care how deep the driver is, I want to see Klippel data for 75+mm of one-way linear excursion.
> 
> I just did a quick search and found they spec the Xmax at 34mm one-direction, not 75mm. Even if you took it upon yourself to merge both forward and rearward you would end up with 68mm of total (rearward and forward) linear travel, not 75mm.
> 
> Does Earthquake have any Klippel data to back up their Xmax claim on thier design? I'm curious because that's an awesome amount of linear stroke in such a shallow depth package.


Its 2 3/4 peak to peak excursion, my apologies for jumping the gun there. I do have another sws 15 that I'd love to be tested also.


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## strakele

Electrodynamic said:


> The BM mkIII and mkIV are not in a low Qtc alignment when installed in its proper 0.5 ft^3 enclosure yet you will not find a single user saying that they put it in a larger box and it sounded better. 0.5 ft^3 to 0.6 ft^3 is optimum for the BM mkIV woofer regardless of what a WinISD says.
> 
> And as mentioned above, a BM mkIV in 0.5 ft^3 sealed is usually flat down to/below 20 Hz in a vehicle.


I haven't ever seen a user post that they put a BM in anything other than ~.5 cubic feet. I assume that since that's what you recommend, you've tried many different size enclosures. What was different about the larger enclosures that made you decide to recommend .5 cubic feet? Was that just the best balance of low extension in car, size, and retaining the best power handling and limiting xmax?


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## AtlasMick

I've got the SI BM mkIV's in a small sports car. Before EQ I was bottoming them out around 45hz due to gain of the cabin. EQ'd that peak down and they play at damn good volume all the way below 20hz.


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## quality_sound

A peak because of cabin gain won't make a sub bottom out.


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## AtlasMick

I was sending it a bit more power than required.


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## quality_sound

I just noticed your screen name. Aren't your enclosures a little smaller than recommended as well?


Sent from my iPhone using Tapatalk


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## AtlasMick

quality_sound said:


> I just noticed your screen name. Aren't your enclosures a little smaller than recommended as well?
> 
> 
> Sent from my iPhone using Tapatalk


I've got 3 boxes, 2 of them are smaller at about .4 with 1 woofer each, and one common chamber with two of the subs is about 1.1, so slightly larger than required. All of the subs behave the same.


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## quality_sound

Interesting. I've never seen that in any
Of the others. I wonder if it's equipment related then. Like a built in bass boost somewhere. Bertholomey never mentioned a peak in his BRZ but it could have just been an omission. I'm thinking about picking up a pair of the MkIVs myself but I haven't decided yet. 


Sent from my iPhone using Tapatalk


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## BuickGN

Displacement and enclosure size. 

Those complaining of slow, boomy bass that doesn't extend much below 50hz describe a classic example of being in too small of an enclosure.

I've been wanting to use some good shallow subs like the JL 13TW5 in an IB configuration like an easily removable baffle for my new BMW. I wouldn't be worried about low frequency extension at all. Output at low frequencies might not be the best due to displacement but I'm sure the response will be plenty flat down to 30hz. 

I think the shallow subs' reputation for poor low frequency extension is the same as a 15" sub's reputation for being slow and boomy compared to it's smaller versions. The larger sub is less likely to have enough airspace due to trunk space limitations just like a shallow sub is more likely to be put into a tiny enclosure that won't allow it to "breathe" and go low without EQ and more power.

Last, I can't see a shallow sub in it's optimal airspace having any less extension than a "regular" sub with the same cone area and excursion. If your shallow sub does not have enough low end and you're not pushing it's excursion limits, it can benefit from EQ or a larger box to get the desired extension. I'm sure my IDMax15s would have no low end either if they were squeezed into a 1 cube box.


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## fcarpio

Alpine shallows drop pretty nicely for me, and they have good output to boot.


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## Infinity

Do any of the "shallows" model well for IB use? I LOVE doing stealthy installs, and I can think of lots of uses for IB shallow mounts. I fear lack of excursion would be an issue with most


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## rxonmymind

So if you were to take two subs of equal size say Pioneer 10" TS-SW2502 shallow sub and a JL audio 10" Tw3 and put them both in the exact same size enclosure would they not sound the same essentially? Especially once it's ran through a dsp to further control and improve sonic frequency? Guess bottom line will a $500 or $300 sub have better sound than a $150 in the exact same controled parameters?


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## 2010hummerguy

Infinity said:


> Do any of the "shallows" model well for IB use? I LOVE doing stealthy installs, and I can think of lots of uses for IB shallow mounts. I fear lack of excursion would be an issue with most


The Earthquake SWS series may work IB.


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## Thumper26

I started with a pair of earthquake sws 10's IB, but ended up making aperiodic enclosures for them. They weren't bad IB, just were better with some resistance. I was also trying to fix blending issues on a MECA stock install, so a better processor would have also helped. I plan on pulling mine soon, let me know if you want them.


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## Electrodynamic

BuickGN said:


> Displacement and enclosure size.
> 
> Those complaining of slow, boomy bass that doesn't extend much below 50hz describe a classic example of being in too small of an enclosure.
> 
> I've been wanting to use some good shallow subs like the JL 13TW5 in an IB configuration like an easily removable baffle for my new BMW. I wouldn't be worried about low frequency extension at all. Output at low frequencies might not be the best due to displacement but I'm sure the response will be plenty flat down to 30hz.
> 
> *I think the shallow subs' reputation for poor low frequency extension is the same as a 15" sub's reputation for being slow and boomy compared to it's smaller versions.* The larger sub is less likely to have enough airspace due to trunk space limitations just like a shallow sub is more likely to be put into a tiny enclosure that won't allow it to "breathe" and go low without EQ and more power.
> 
> Last, I can't see a shallow sub in it's optimal airspace having any less extension than a "regular" sub with the same cone area and excursion. If your shallow sub does not have enough low end and you're not pushing it's excursion limits, it can benefit from EQ or a larger box to get the desired extension. I'm sure my IDMax15s would have no low end either if they were squeezed into a 1 cube box.


Most shallow subwoofers are simply not designed for low frequency extension in a small box but are rather designed for output in the 50 Hz region because that is considered "low" to most consumers.

Excursion has nothing to do with how low a woofer will play in a sealed box. Linear excursion does, however, determine how LOUD a woofer will play down low in a sealed box. A less sensitive subwoofer will play lower louder than the more sensitive subwoofer in a small sealed box. 

Transient response in subwoofers is directly proportional to Re:Le as you can read here in this document.  Shallow woofers are optimized to reach a specific target audience. Different companies target different audiences. For instance, the BM mkIII/mkIV subwoofers offer the best low frequency extension in a 0.5 ft^3 sealed box than all other shallow woofers regardless of manufacturer name. Couple that with low Le per Re and you have yourself a "fast" response subwoofer in a tiny sealed box that is capable of respectable output to where 99% of customers look towards their subwoofer install and say "is that shallow woofer really digging that deep?"


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## cajunner

since most pop/rock music has most bass content reaching down to 40 hz, on 85% of tracks it makes sense that large corporation/bean counters, would spec their shallow/low cost subs, to have higher output a bit higher up, than make the compromises required to squeeze out that last octave on the bottom. MORE output across the spectrum trumps the need for bottom octave rendering, and that's why most shallow subs operate slightly above the normal subwoofer FR drop-offs.

SI took a sound quality approach to their system and most people are happy here, with the choice to produce a subwoofer that is mildly less potent, in the big 60 hz whack region so that it could extend down cleanly. 

Someone on the street may prefer the output of a maximized for 40 hz and up presentation, and that's going to drive a lot of woofers out of the door based on initial impressions, and for those bass-driven motorheads that don't really give a **** if the sub goes flat to 20 hz or not, as long as the 40 hz and up is available without blowing up and comes close to regular basket designs.


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## Electrodynamic

cajunner said:


> since most pop/rock music has most bass content reaching down to 40 hz, on 85% of tracks it makes sense that large corporation/bean counters, would spec their shallow/low cost subs, to have higher output a bit higher up, than make the compromises required to squeeze out that last octave on the bottom. *LESS output across the subwoofer bandwidth trumps the need for bottom octave rendering, and that's why most shallow subs operate slightly above the normal subwoofer FR drop-offs.*


I completely disagree and I have edited your post to accurately portray what is really going on. If you agree that subwoofers should only be playing from 40 Hz up to 80 Hz why not cut off your tweeters at 12,000 Hz? After all, there isn't much information above 12,000 Hz anyway.  I doubt most customers that look at the BM mkIV and read up on the woofers performance and its target abilities listen to rock/pop music on their FM radio, haha. 



cajunner said:


> SI took a sound quality approach to their system and most people are happy here, with the choice to produce a subwoofer that is mildly less potent, in the big 60 hz whack region so that it could extend down cleanly.


What you are referring to as the "whack" in the 60 Hz region is actually mechanical and BL distortion. If you like the sound of distortion via those specific attributes you are correct in the BM mkIV does not have those. However, I'm sure many people have not read up on the shallow BM mkIII/mkIV series and actually want that punch more than a flat linear frequency response.


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## quality_sound

Exactly. Impact comes from your midbasses and quite a bit higher than most people associate with bass. 


Sent from my iPhone using Tapatalk


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## Ultimateherts

quality_sound said:


> Exactly. Impact comes from your midbasses and quite a bit higher than most people associate with bass.
> 
> 
> Sent from my iPhone using Tapatalk


Then what frequency range makes bass travel so far (hearing a car before seeing it)?


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## cajunner

Electrodynamic said:


> I completely disagree and I have edited your post to accurately portray what is really going on. If you agree that subwoofers should only be playing from 40 Hz up to 80 Hz why not cut off your tweeters at 12,000 Hz? After all, there isn't much information above 12,000 Hz anyway.  I doubt most customers that look at the BM mkIV and read up on the woofers performance and its target abilities listen to rock/pop music on their FM radio, haha.
> 
> *
> 
> 
> 
> so if I read you correctly, you are saying that your shallow XBL sub is actually more efficient across the subwoofer bandwidth, and this is true because it can play louder lower? I am not sure if I understand, but my observation is that the cross-section of the gap usually determines overall sensitivity and underhung geometry is flux-limited, and XBL aligns more to the underhung side, so although you may have more usable flux across the gap, the ability of an XBL sub to make 40-80 hz bass, is less than the comparable overhung motor. I have read people say XBL can be more efficient than overhung, but in commercial/retail application and practice there is the rule, and no exceptions. Show me where a sub that excels at 20 hz is able to produce as much bass in the 40-90 hz region, as one that is engineered for a 40-90 hz response curve, and you'll have me.
> 
> Click to expand...
> 
> *
> What you are referring to as the "whack" in the 60 Hz region is actually mechanical and BL distortion. If you like the sound of distortion via those specific attributes you are correct in the BM mkIV does not have those. However, I'm sure many people have not read up on the shallow BM mkIII/mkIV series and actually want that punch more than a flat linear frequency response.


this "whack" is less properly defined, I would submit that the 60 hz fundamental is where most of the subwoofers' work ends up, and a sub that can produce this note with more authority is going to wow people who don't need the 20 hz flat capability. 

I also will add that your suggestion that response above 12 Khz is necessary for audio, is dependent on source material, and I believe many people with systems that have response roll off above 12 Khz, are in fact, enjoying their sound and may not notice the missing part of the spectrum.

Also, many people are hearing impaired, from damage and age and would hardly notice the loss of those higher frequencies in normal listening.

I am not saying your shallow sub is lacking when I say it trades efficiency for a balanced presentation that allows the sub to produce very low tones.

I believe you would have to admit, the XBL motor design you implement is able to be beaten on output/sensitivity based on the inherent limitations of XBL geometry, since most people have noted that although they love the sound, it's not as loud as most subs that don't have shallow design compromise, and that includes the motor.

You say yourself, if you want to boom, the BM is not your woofer. I am just agreeing with you, after all.


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## quality_sound

Ultimateherts said:


> Then what frequency range makes bass travel so far (hearing a car before seeing it)?



Depends on where you're standing. Bass waves are incredibly long. 


Sent from my iPhone using Tapatalk


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## Ultimateherts

quality_sound said:


> Depends on where you're standing. Bass waves are incredibly long.
> 
> 
> Sent from my iPhone using Tapatalk


That's what she said... Thanks for the response


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## captainobvious

quality_sound said:


> Interesting. I've never seen that in any
> Of the others. I wonder if it's equipment related then. Like a built in bass boost somewhere. Bertholomey never mentioned a peak in his BRZ but it could have just been an omission. I'm thinking about picking up a pair of the MkIVs myself but I haven't decided yet.
> 
> 
> Sent from my iPhone using Tapatalk



That's probably because both he and I use EQ. The sub may have more output at 60 hz than 20hz in some cabins, but using eq to bring down the extra output and level it out means you get more efficient use of your amplifier power  You already know this of course, but just pointing it out for others.

Also, each vehicle will have different effects on the overall response.

I'm still amazed at how low this extends and how cleanly it plays. I'd love to hear a setup with several of these. It's the cleanest, most accurate I've ever had bass in any one of my vehicles over the years. Would I like more output, sure, but not at the sacrifice of accuracy. I'll simply add more of them


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## captainobvious

BuickGN said:


> Displacement and enclosure size.
> 
> Those complaining of slow, boomy bass that doesn't extend much below 50hz describe a classic example of being in too small of an enclosure.
> 
> I've been wanting to use some good shallow subs like the JL 13TW5 in an IB configuration like an easily removable baffle for my new BMW. I wouldn't be worried about low frequency extension at all. Output at low frequencies might not be the best due to displacement but I'm sure the response will be plenty flat down to 30hz.
> 
> I think the shallow subs' reputation for poor low frequency extension is the same as a 15" sub's reputation for being slow and boomy compared to it's smaller versions. The larger sub is less likely to have enough airspace due to trunk space limitations just like a shallow sub is more likely to be put into a tiny enclosure that won't allow it to "breathe" and go low without EQ and more power.
> 
> Last, I can't see a shallow sub in it's optimal airspace having any less extension than a "regular" sub with the same cone area and excursion. If your shallow sub does not have enough low end and you're not pushing it's excursion limits, it can benefit from EQ or a larger box to get the desired extension. I'm sure my IDMax15s would have no low end either if they were squeezed into a 1 cube box.



For the absolutely tiny enclosure size required, I'd be MUCH more inclined to do 2 or 3 of the BM mkIV's in a shallow back wall enclosure. I had my JL 13TW5 in a full cube and it still couldn't play as low as the mkIV does, in half the enclosure size. The JL will be louder, but you'll be missing some low end. 3 mkIV's on a back wall enclosure would be unbelievably sick. Wish I had the space for that. I'd have to do mine in the trunk floor since I have a hatchback. :blush:

If it were a price difference thing, I could see it. But since 3 BM mkIV's can be had for the cost of a pair of 13TW5's, you get better low end extension, lower distortion AND more output. Win-Win-Win


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## Electrodynamic

cajunner said:


> this "whack" is less properly defined, I would submit that the 60 hz fundamental is where most of the subwoofers' work ends up, and a sub that can produce this note with more authority is going to wow people who don't need the 20 hz flat capability.
> 
> I also will add that your suggestion that response above 12 Khz is necessary for audio, is dependent on source material, and I believe many people with systems that have response roll off above 12 Khz, are in fact, enjoying their sound and may not notice the missing part of the spectrum.
> 
> Also, many people are hearing impaired, from damage and age and would hardly notice the loss of those higher frequencies in normal listening.
> 
> I am not saying your shallow sub is lacking when I say it trades efficiency for a balanced presentation that allows the sub to produce very low tones.
> 
> I believe you would have to admit, the XBL motor design you implement is able to be beaten on output/sensitivity based on the inherent limitations of XBL geometry, since most people have noted that although they love the sound, it's not as loud as most subs that don't have shallow design compromise, and that includes the motor.
> 
> You say yourself, if you want to boom, the BM is not your woofer. I am just agreeing with you, after all.


So you are agreeing with yourself that if you after "boom boom boom" and nothing more do not look at a linear subwoofer. I agree. If you are after a linear RESPONSE do not look at linear motor topology suboofer. I agree as well.

However, I do *NOT* agree /*KNOW* that XBL^2 has "trade-off's" as the split gap nature simply divides the flux. XBL^2 does not REDUCE flux, but rather divide the lines of flux like a small pebble does the same thing in a large stream. The small rock/pebble doesn't reduce the amount of water flowing through the stream, but rather it diverts the flow of water through the stream with the same overall flow. Once again your "understanding" is flawed much like your "understanding" of BL symmetry in the TM65 thread. It is one thing to question but it is another thing to state erroneously.


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## cajunner

Electrodynamic said:


> So you are agreeing with yourself that if you after "boom boom boom" and nothing more do not look at a linear subwoofer. I agree. If you are after a linear RESPONSE do not look at linear motor topology suboofer. I agree as well.
> 
> However, I do *NOT* agree /*KNOW* that XBL^2 has "trade-off's" as the split gap nature simply divides the flux. XBL^2 does not REDUCE flux, but rather divide the lines of flux like a small pebble does the same thing in a large stream. The small rock/pebble doesn't reduce the amount of water flowing through the stream, but rather it diverts the flow of water through the stream with the same overall flow. Once again your "understanding" is flawed much like your "understanding" of BL symmetry in the TM65 thread. It is one thing to question but it is another thing to state erroneously.


show me, the example that proves the rule, or show me the exception, then.

if you look at the long line of XBL subs to hit the market, they all do not quite reach the efficiency and sensitivity marks of the better performing examples from the majors. 

Start from the Brahma and work your way, each new entry into the market promises linearity and if the QC is good, you get linearity. I like low distortion, I like staying clean in an extraordinary BL plateau, I like the whole bit of it, I never said I didn't and since Neo-Radial underhung is probably more closely related to the XBL architecture, I like that about it as well.

And you have Neo-Radial capable of massive SPL, in the Aura 1808. What XBL product would resemble that performance, if you don't mind my asking?

Somehow, you see my posts as challenges, when I'm just learning here. If it appears that somehow I am pushing against your expertise, let me clear that right up. You are the expert, and I'm just a yahoo on the internet, I hope that I don't have to make that observation on a regular basis, not because I'm vain, but because it's tedious.


Now that you have put your best foot forward, give us the skinny on XBL examples that do not leave anything on the table in terms of performance any one of us can easily understand.


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## Electrodynamic

cajunner said:


> show me, the example that proves the rule, or show me the exception, then.
> 
> if you look at the long line of XBL subs to hit the market, they all do not quite reach the efficiency and sensitivity marks of the better performing examples from the majors.
> 
> Start from the Brahma and work your way, each new entry into the market promises linearity and if the QC is good, you get linearity. I like low distortion, I like staying clean in an extraordinary BL plateau, I like the whole bit of it, I never said I didn't and since Neo-Radial underhung is probably more closely related to the XBL architecture, I like that about it as well.
> 
> And you have Neo-Radial capable of massive SPL, in the Aura 1808. What XBL product would resemble that performance, if you don't mind my asking?
> 
> Somehow, you see my posts as challenges, when I'm just learning here. If it appears that somehow I am pushing against your expertise, let me clear that right up. You are the expert, and I'm just a yahoo on the internet, I hope that I don't have to make that observation on a regular basis, not because I'm vain, but because it's tedious.
> 
> 
> Now that you have put your best foot forward, give us the skinny on XBL examples that do not leave anything on the table in terms of performance any one of us can easily understand.


It is one thing to question, but is a completely different thing to state something as fact to a manufacturer when it is not fact. If you are asking, then ASK, do not STATE. 

It is very late and I will entertain a response after I come back from CES. Have fun guys.


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## 2010hummerguy

Electrodynamic said:


> It is one thing to question, but is a completely different thing to state something as fact to a manufacturer when it is not fact. If you are asking, then ASK, do not STATE.
> 
> It is very late and I will entertain a response after I come back from CES. Have fun guys.


Have fun and travel safe Nick!


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## sundownz

cajunner said:


> if you look at the long line of XBL subs to hit the market, they all do not quite reach the efficiency and sensitivity marks of the better performing examples from the majors.


I'll toss something out there in the mix for you.

Sensitivity vs. excursion -- as BL falls so does sensitivity -- in a linear BL design sensitivity doesn't fall as much over stroke.

So sensitivity, as with the flux itself, is "moved around" rather than tossed out for the most part.


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## cajunner

sundownz said:


> I'll toss something out there in the mix for you.
> 
> Sensitivity vs. excursion -- as BL falls so does sensitivity -- in a linear BL design sensitivity doesn't fall as much over stroke.
> 
> So sensitivity, as with the flux itself, is "moved around" rather than tossed out for the most part.


I get this, and it does make up for some of the difference, "in my mind" haha..

but, I read things like "XBL designed 99 db sensitivity" and I don't see any available.

I mean, it might just be me, living in a bubble or whatever, that I don't have access to these magical subs and speakers that are just 1 db off the 'top of the realm' in sensitivity, or even max output.

And, I also understand that the lack of distortion adds, to the perception that loud, isn't really loud.

But, I try to keep a footing in both camps, I come from the old school distortion memory collective, and I make room for increasingly linear and less distorted options as they come available, hoping that I'll eventually see the XBL woofer with the same output capability as the near-pro sound stuff that sets the bar, and ruled the scene way back when.

here's a question:

would it be the added pressure gradient of the automobile interior, that drives the need for more clarity in the bass, that helps make XBL a superior topology for those looking for loud, but clear? Is it the environment that sets XBL as the superior topology, since it is able to keep cone control further into the stroke, which adds definition, even if it is not augmented by higher distortion products?

And is that why XBL is not as entrenched in home audio designs, or why the Adire Extremis didn't last as a marketable entry? I know, we have the Anarchy and all, SDX7 or subduction, but it doesn't appear to have been picked up by the majors, overall.

And as a response to your position, I would say the added BL over stroke, is at the same importance level as the sharper drop-off at the ends of stroke, in relating to audible distortion with still increasing output.

IOW, a regular overhung will get sloppy, but it will continue to increase in SPL where an XBL design will just simply stop getting louder as you turn the knob.

For SQ guys, that's a general sign of abuse and most will set their levels to below the audible distortion, but the average "bass head" will need to push their woofers to the 10% THD range on a regular basis, and it doesn't matter where the SPL sits at that point. 

The XBL woofer could be pushing 144 db, cleanly and the guy will choose the overhung sub doing 140 db with distortion, as their clear favorite. I don't know if that's just being agreeable, but I'd like to see that as the case and not the other way around, with the XBL woofer doing 140 db cleanly, and the overhung woofer doing a sloppy 144 db, and it be a no-brainer...


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## sundownz

You would be really surprised if you knew how many things DO actually use XBL^2 technology. I cannot mention any names -- and many of the products do not list the fact that it is used (magic sauce). Dan is a *very* busy man in the background.

-----

"IOW, a regular overhung will get sloppy, but it will continue to increase in SPL where an XBL design will just simply stop getting louder as you turn the knob."

An over-hung will start getting quieter sooner ; as it's BL drops off almost from the beginning. At the absolute maximum limit, which I'd say isn't seen often, the XBL does drop off quicker -- which can also help prevent soft part damage.

Within the linear range -- the XBL driver will actually do the opposite of what you suggest; it will keep getting louder for longer ranges of stroke.


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## captainscarlett

A few quotes;



> The main reason why they suck--most of them--is because they comply with small / tight spaces only by the virtue of their physical geometry. From an electro-mechanical perspective, they're just as space-hungry as the next sub, if not more so. As for thin / shallow boxes, that presents it's own set of acoustic issues. If you've ever modeled a Voigt pipe or even a completely closed-end waveguide, you may be aware of the standing wave cross-cancellation that such chamber geometry suffers from.





> Are you talking about the 13TW5? Given 0.8 cubic feet of loading volume, there aren't even that many 8" drivers that I'd consider appropriate, let alone a 13.5" driver. How are you modeling this thing to arrive at 0.8 cubes as "spot on"?





> Yep... There's really nothing about the parameters that makes these particularly suitable for small enclosures, they just have a shallow mounting depth which, as you've pointed out, does more harm than good. As for manufacturer recommendations, I think we've beat that issue well into the ground; they're bull****.





> Not really. Shallow subs are just that - physically shallow. You don't determine the proper size (or shape) of an enclosure by the woofer's mounting depth. This is just a gimmick to make implementing a compromised size/shape enclosure physically possible.


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## 2010hummerguy

sundownz said:


> You would be really surprised if you knew how many things DO actually use XBL^2 technology. I cannot mention any names -- and many of the products do not list the fact that it is used (magic sauce). Dan is a *very* busy man in the background.


Exactly, I've heard he spends up to half the year at the factories in China. Crazy!


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## Hillbilly SQ

How bout some comic relief in this thread? Who all remembers this hilarious gems?
https://www.youtube.com/watch?v=IZllYbwz5Tw


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## captainscarlett

Hillbilly SQ said:


> How bout some comic relief in this thread? Who all remembers this hilarious gems?
> https://www.youtube.com/watch?v=IZllYbwz5Tw


.... Ah the good ol' days, when xmax wasn't what 99.9% of the populous considered to be the mark of good subwoofer!

Look at the magnet on that! That wasn't a euphemism


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## Black Rain

captainobvious said:


> For the absolutely tiny enclosure size required, I'd be MUCH more inclined to do 2 or 3 of the BM mkIV's in a shallow back wall enclosure. I had my JL 13TW5 in a full cube and it still couldn't play as low as the mkIV does, in half the enclosure size. The JL will be louder, but you'll be missing some low end. 3 mkIV's on a back wall enclosure would be unbelievably sick. Wish I had the space for that. I'd have to do mine in the trunk floor since I have a hatchback. :blush:
> 
> If it were a price difference thing, I could see it. But since 3 BM mkIV's can be had for the cost of a pair of 13TW5's, you get better low end extension, lower distortion AND more output. Win-Win-Win


Ok, I've been readingthis thread and of course its got my complete attention. Now, I've had the chance to hear the MkIV, 13tw5, C12 and the T12, but I do have to say this, of all of these shallow subs, the MKIV has better overall low frequency extension.

Now, going to what you were saying Steve, you think that having 3 MKIV, say in my Sorento, would be mind blowing? What are yours and even Nick's views on this?

Reason for this question is, everyone all speaks of the shallow and how they perform, but 95% of those using and commenting have them in a small sports car or a sedan. There is never any talk about how it has performed in a bit larger cabin with the same enclosure sizes.


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## captainobvious

Hey Juan 

I'd be willing to bet it would be killer. 3 12's is a lot of cone area. I have an open cabin as well with the hatchback so there's a good amount of cubic space there. Not as much as the Sorrento I'm sure, but still. 
I'm going to add 2 in the back for more cone area and I fully expect it to kick some nuts.


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## 2010hummerguy

My MKIII had lower extension in my Grand Cherokee than my MKIV has in my tiny truck. Big cabin=big bass; vans, wagons and SUVs are the best for getting low. Sedans on the other hand are the dealbreakers for output. Little spaces may be good for output but are challenging for extension.


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## Electrodynamic

Black Rain said:


> Ok, I've been readingthis thread and of course its got my complete attention. Now, I've had the chance to hear the MkIV, 13tw5, C12 and the T12, but I do have to say this, of all of these shallow subs, the MKIV has better overall low frequency extension.
> 
> Now, going to what you were saying Steve, you think that having 3 MKIV, say in my Sorento, would be mind blowing? What are yours and even Nick's views on this?
> 
> Reason for this question is, everyone all speaks of the shallow and how they perform, but 95% of those using and commenting have them in a small sports car or a sedan. There is never any talk about how it has performed in a bit larger cabin with the same enclosure sizes.


Ok, why not comment on how 24" woofers have performed in small vehicles? Would it be "mind blowing" as you stated in your reply? Apples to apples.

It all depends on your reference and your actual, honest, requirement. Many people say they want a certain requirement (SQ) when they really want another (SPL). SQ is subjective and that is the quintessential "issue" with "sound quality" in that sound quality is subjective. SPL, on the other hand, is NOT subjective. When you arrive in the lanes in your sanctioned body class and you compete and are beat by 0.01 dB you have lost to your competitor that scored 0.01 dB higher than you.


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## captainscarlett

Electrodynamic said:


> SPL, on the other hand, is NOT subjective. When you arrive in the lanes in your sanctioned body class and you compete and are beat by 0.01 dB you have lost to your competitor that scored 0.01 dB higher than you.



But isn't there mass confusion between audible loudness, and Sound Pressure?


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## Black Rain

I wonder if anyone has attempted to place more than 2 of them in a vehicle? Nick, can give some insight on this?


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## 2010hummerguy

Black Rain said:


> I wonder if anyone has attempted to place more than 2 of them in a vehicle? Nick, can give some insight on this?


I've seen setups on the web running 3-4 of them. Wish I had that kind of space to work with!


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## Electrodynamic

Architect7 said:


> I've seen setups on the web running 3-4 of them. Wish I had that kind of space to work with!


What are we talking about regarding "them"? Are you asking about HS-24's used in a vehicle? Or just a pair of 18's, 15's or 12's in a vehicle? To the best of my knowledge [I build each HS-24 by hand] there is only one vehicle with two 24's here in the states and that vehicle's subwoofer system is in the very beginning stages of being built.


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## Electrodynamic

captainscarlett said:


> But isn't there mass confusion between audible loudness, and Sound Pressure?


Yes there is. Distortion is confused with SPL far too often. Case in point was back in the day when the Brahma 12 was introduced. Customers went into the lanes putting up 144 dB scores only to report that it "wasn't loud" compared to their previous setup. It wasn't "loud" because the subwoofer was CLEAN.


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## Bayboy

Subscribed..


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## 2010hummerguy

Electrodynamic said:


> What are we talking about regarding "them"? Are you asking about HS-24's used in a vehicle? Or just a pair of 18's, 15's or 12's in a vehicle? To the best of my knowledge [I build each HS-24 by hand] there is only one vehicle with two 24's here in the states and that vehicle's subwoofer system is in the very beginning stages of being built.


That was back in January and my memory is pretty fuzzy but I believe I was referring to 3-4 MKIVs in a vehicle, not the 24's. Two 24's in a rig is going to be INSANE!


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## Nismo

Electrodynamic said:


> Yes there is. Distortion is confused with SPL far too often. Case in point was back in the day when the Brahma 12 was introduced. Customers went into the lanes putting up 144 dB scores only to report that it "wasn't loud" compared to their previous setup. It wasn't "loud" because the subwoofer was CLEAN.


Humans have such short memory. Thanks for the reminder!

Eric


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## Electrodynamic

Nismo said:


> Humans have such short memory. Thanks for the reminder!
> 
> Eric


Long time no see.


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## gckless

Electrodynamic said:


> What are we talking about regarding "them"? Are you asking about HS-24's used in a vehicle? Or just a pair of 18's, 15's or 12's in a vehicle? To the best of my knowledge [I build each HS-24 by hand] there is only one vehicle with two 24's here in the states and that vehicle's subwoofer system is in the very beginning stages of being built.


SI is not the only company with 24" drivers 

In fact, I have one sitting about 10 feet from me that you did not build.


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## Electrodynamic

gckless said:


> SI is not the only company with 24" drivers
> 
> In fact, I have one sitting about 10 feet from me that you did not build.


WHAT?!?!?!?! 

Good to know.


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## Pianista

Jlaudio 13tw5 - 3 on a recommended thin closed enclosure... sounds very very nice and controlled. Audison av5.1k pushing it... 

Un saludo del pianista


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