# Sq subs



## Jahuntley79 (Jan 5, 2020)

I’ve been away from car audio for the past year or so. Recently a GB12 was stole from my truck. I’m considering replacing it with either another GB12, esostar 1200 or something different. Whatever I get will be in a sealed enclose and will be powered by the sub channel of a mosconi pro 5/30 (so 660w at 4ohms or 1000w at 2ohms).

Interested in thoughts/suggestions for SQ subs and budget is open. The GB12 was probably the best sub I’ve owned, but I’m also open to trying something new.

Current build in 2017 Toyota Tundra crew cab

Pioneer 4400nex hu
Brax ml3 dash mids
Morel mt230 tweeters in sail panels
Center channel: dynaudio e430 + Audiofrog gb10
Audiofrog gb60 in front doors
Morel hybrid mw6 in rear doors
Mosconi pro 5/30 amp
Mosconi pro 4/10 amp
DD dm1000a amp
Addictive Audio p13.4 amp
Helix Ultra dsp
Two JL audio 10tw3s
Audiofrog GB12 sub - No longer there 
Focal Ibus20 8" sub
370a ces alt
Ces 0.8v voltage booster
2 full throttle agm batteries
Big 3 upgrade
Hushmat cld on all doors, rear wall and headliner


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## cdlowe30907 (Nov 21, 2018)

Look into the Stereo Integrity SQL-12


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## ckirocz28 (Nov 29, 2017)

Jahuntley79 said:


> I’ve been away from car audio for the past year or so. Recently a GB12 was stole from my truck. I’m considering replacing it with either another GB12, esostar 1200 or something different. Whatever I get will be in a sealed enclose and will be powered by the sub channel of a mosconi pro 5/30 (so 660w at 4ohms or 1000w at 2ohms).
> 
> Interested in thoughts/suggestions for SQ subs and budget is open. The GB12 was probably the best sub I’ve owned, but I’m alsoopen to trying something new.


I'd suggest an Adire Audio Brahma or a CSS Audio SDX 12 or the SI SQL 12 already mentioned, if those are too large just get another Audiofrog.


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## UNBROKEN (Sep 25, 2009)

I’ve said since 2013 when I got my first one the Illusion C12XL is the best of the best…I won’t use anything else.


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## miniSQ (Aug 4, 2009)

I think Audiomobile makes a great SQ sub too.


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## Jahuntley79 (Jan 5, 2020)

Illusion audio is an interesting idea. I’ve never heard one. How does it compare to a GB12?


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## UNBROKEN (Sep 25, 2009)

Jahuntley79 said:


> Illusion audio is an interesting idea. I’ve never heard one. How does it compare to a GB12?


I’ve never personally even heard a GB12…but I’ve used quite a few top of the heap subs and the C12XL just does it better. I’ve always said…even on this forum years ago…that they have W7 bottom end with Morel Ultimo finesse…and I’ve used both of those in the same vehicle along with the C12XL.


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## Bass Face (May 31, 2021)

The GB12 has a massive value proposition. They are just that damn good. Very few can be that good at that price. A friend of mine compared the Adhire Brahma and the GBs through software. The GB easily outgunned it.


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## 619Tundra (Sep 24, 2020)

GB12 for the win.


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## cman (Aug 24, 2020)

The GB12 specs out on paper and sounds really good, that is what i am running and it would be hard to ask for more.. especially with some EQ it is quite a good sub... but i would also consider morel ultimo titanium (not the cheaper ultimo sc the good one), focal e30kx12, or the raven XL 12 (but the raven is 4 ohm so a bit less power.. i guess it depends on how loud you listen and the drivers sensitivity..


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## ckirocz28 (Nov 29, 2017)

Bass Face said:


> The GB12 has a massive value proposition. They are just that damn good. Very few can be that good at that price. A friend of mine compared the Adhire Brahma and the GBs through software. The GB easily outgunned it.


Nothing wrong at all with the Audiofrog stuff, but they are definitely NOT a bang-for-the-buck item.
Regarding your friend's comparison, Audiofrog's subs are more sensitive than Brahma's, so with the same wattage the GB12 always wins. Here's where the fun starts, feed them both 2000 watts, the GB12 goes up in smoke and the Brahma 12 kicks your ass and begs for more while remaining as clean as the GB12 and delivering 1-2 more db than the GB12 can muster.
GB12 $600
Brahma 12 $500
To be fair, amplification included, they are pretty much about the same value, unless you want that extra loudness, then the Brahma wins.


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## Jahuntley79 (Jan 5, 2020)

In my case, I will “only” have 1k watts. I know it is ample for a GB12, but I’d kind of like to try something different. 

Has anyone used two or more of the following? In my case it will be driven by 660w at 4ohms or [email protected] in a sealed enclosure.

esotar 1200
GB12
JL W7
Morel Ultimo
ID SQL
Illusion C12XL
Raven 12xl


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## Slow Cruiser (Aug 21, 2016)

Acoustic Elegance SBP12


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## SkizeR (Apr 19, 2011)

Bass Face said:


> The GB12 has a massive value proposition. They are just that damn good. Very few can be that good at that price. A friend of mine compared the Adhire Brahma and the GBs through software. The GB easily outgunned it.


The GB12 is one of my favorite subs to date, but this is just not correct or the right way to look at things.

1) Modeling software is ONLY used to calculate how the driver behaves in certain enclosures at and around its resonant frequency. It does not tell you how it'll actually sound overall or how they will behave in the long run. No transient response, distortion, power compression, reliability, etc.. none of that is factored into modeling. You can manipulate modeling to make one look better than the other if you want, but looking at the whole picture, someone who knows what they're looking at can tell that while the GB12 caps out with 1000 watts in a 1 cube enclosure, the Brahma can still match (actually, do just a hair better) it in output and low-frequency extension in the same enclosure, while still having 8.25mm more linear excursion to go. So if you really wanted to, you can throw another 1k of power at it and beat it in all regards if needed. After modeling, accounting for xmax to be reached at 20hz, the brahma is capable of 4db more output from 100hz down, and match output at 180hz. Now messing with it a bit, this same situation but sticking the brahma in a 0.5 cube enclosure while leaving the gb12 in a 1 cube enclosure, it still has more output from 200hz down to 0hz.
TLDR: learning how to actually use the modeling software and understanding what you are looking at is important.

2) The Adire Brahma, frankly, is more capable on paper outside of a higher inductance spec. I was skeptical of them when they were first re-announced, but after tuning a friend's car with them, I realized they weren't playing around. Much higher real-use power handling, even smaller box allowances, and similar sound overall. I actually just used these in a customers car for myself the first time the other day. We did 0.5 cubes per 12" sub. Fvcking insane, and I told Matt "bull. shiit." when he told me manufacture spec was 0.6 cubes for a 0.7 QTC. So we said screw it, let's see how it does in that. Turned out to be 0.5 after displacement, and they were flat down to as low as my microphone preamp could read (something like 8 or 9 Hz). For those that occasionally (or often) get down and dirty with their subs while still having a great sounding system, this is a new standard. Haven't heard or used the SQL12 yet, so cannot compare.


That said, there's not a single sub mentioned in this thread so far that I would hesitate to put in my car besides the w7.


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## MF Toker (Jan 10, 2011)

I'm sure the Audiofrogs at are awesome. Measurements on their mids and tweeters show that they are very low distortion, sure the subs fallow suit. 

That being said I'm one of those people that think subs don't have to be super high performance to keep up with a flagship front stage, at least not when lowpassed at typical points, 60/80hz. If you want to run them higher then buy the best subs you can afford even with a high budget I'd likely take a chance on something like the new Reference HE Daytons, if you have the depth look into the RSS315HE-22. Half to a quarter or so of the price of the subs your considering with likely more xmax.


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## MF Toker (Jan 10, 2011)

SkizeR said:


> That said, there's not a single sub mentioned in this thread so far that I would hesitate to put in my car besides the w7.


What don't you like about the W7? Haven't heard one personally but have read many positive reviews but I'm pretty skeptical of the average expectation.. most people are easily impressed.

Saw earlier that you're not a fan of their amps.


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## nadams5755 (Jun 8, 2012)

i've had two raven 10xls on 500w each, they sound great with extension down to 20hz.

currently i have two illusion c12xls on 1100w each, they also sound great with extension down to 20hz. i made the change to have more effortlessness (less excursion/tactile feedback) in that bottom octave.

both setups 1-1.1cu each, up-firing in a hatchback.

i've heard the adire tumult 12s in 1.2cu each with like 900w each, they sounded really good as well.


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## Jahuntley79 (Jan 5, 2020)

Thanks, Nick. I was hoping you would respond. Here is an example of how small of a world we live in, guess who built the enclosure and installed my GB12 last year, Matt K. Hope you guys are doing well.

Now I’m leaning towards the Brahma. Being able to get by with a smaller enclosure is a big plus and it’s fun to try out a different sub.


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## MF Toker (Jan 10, 2011)

Jahuntley79 said:


> Thanks, Nick. I was hoping you would respond. Here is an example of how small of a world we live in, guess who built the enclosure and installed my GB12 last year, Matt K. Hope you guys are doing well.
> 
> Now I’m leaning towards the Brahma. Being able to get by with a smaller enclosure is a big plus and it’s fun to try out a different sub.


If I went for some high end subs Adire would be the front runner, maybe Acoustic Elegance if IB... 2-3 of the Adire Kali 18"s would be used in my dream build.


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## SkizeR (Apr 19, 2011)

MF Toker said:


> That being said I'm one of those people that think subs don't have to be super high performance to keep up with a flagship front stage, at least not when lowpassed at typical points, 60/80hz.


I _used _to agree with you. I've come to realize that with everything else in your system being good, a sub that isn't great will stick out and make its presence known.


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## SkizeR (Apr 19, 2011)

Jahuntley79 said:


> Thanks, Nick. I was hoping you would respond. Here is an example of how small of a world we live in, guess who built the enclosure and installed my GB12 last year, Matt K. Hope you guys are doing well.
> 
> Now I’m leaning towards the Brahma. Being able to get by with a smaller enclosure is a big plus and it’s fun to try out a different sub.


ayyy whats up. We are doing great. We were supposed to be in Oklahoma together right now but I missed my flight lol


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## Berk (Jul 11, 2021)

Have you heard Brax? I have the ML10. Amazing sub.


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## Jahuntley79 (Jan 5, 2020)

I have brax ml3 mids, but I’ve never heard their subs.


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## Jahuntley79 (Jan 5, 2020)

@skizer….

Besides the stolen GB12, I’m doing great as well. Going to put an alarm on my truck before the next sub gets installed.


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## daloudin (Nov 2, 2020)

Personally have had the Brahma 12, 12W7, 12 GTi MK2, GB12 and currently running SQL12 (along with a bunch of 15s as well) all in sealed enclosure at 0.7 Qts or a little lower. 

12W7 went into power compression due to thermal limits to fast. Needed big box. 

GTi MK2 was all slam with no finesse. Bigger box. 

GB12 was probably the most accurate but ran out of steam too fast - takes 2 of them to keep up with these others. 

Brahma and SQL are neck and neck and only time will tell if the SQL has the durability long term. The SQL seems more efficient to me as it comes on a little sooner but they were not in identical vehicles or signal paths.

The SQL also wants 0.7 cuft and is a little more affordable but both want big power. 



Sent from my SM-G965U using Tapatalk


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## MF Toker (Jan 10, 2011)

SkizeR said:


> I _used _to agree with you. I've come to realize that with everything else in your system being good, a sub that isn't great will stick out and make its presence known.


What is good, in terms of subs? Low distortion with adequate xmax and power handling?

Serious question.


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## nadams5755 (Jun 8, 2012)

the other reason i like the raven/illusion subs: neo magnets. they don't take a lot of effort to wrestle them around a vehicle.


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## SkizeR (Apr 19, 2011)

MF Toker said:


> What is good, in terms of subs? Low distortion with adequate xmax and power handling?
> 
> Serious question.


Depends on how much output you really need. If it's a lot, I would say Brahma. If you don't need as much and want something that matches the GB12, the C12XL/Raven like nadams5755 mentioned above is also really good. I use the shallow version in my car and love them.


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## ckirocz28 (Nov 29, 2017)

SkizeR said:


> The GB12 is one of my favorite subs to date, but this is just not correct or the right way to look at things.
> 
> 1) Modeling software is ONLY used to calculate how the driver behaves in certain enclosures at and around its resonant frequency. It does not tell you how it'll actually sound overall or how they will behave in the long run. No transient response, distortion, power compression, reliability, etc.. none of that is factored into modeling. You can manipulate modeling to make one look better than the other if you want, but looking at the whole picture, someone who knows what they're looking at can tell that while the GB12 caps out with 1000 watts in a 1 cube enclosure, the Brahma can still match (actually, do just a hair better) it in output and low-frequency extension in the same enclosure, while still having 8.25mm more linear excursion to go. So if you really wanted to, you can throw another 1k of power at it and beat it in all regards if needed. After modeling, accounting for xmax to be reached at 20hz, the brahma is capable of 4db more output from 100hz down, and match output at 180hz. Now messing with it a bit, this same situation but sticking the brahma in a 0.5 cube enclosure while leaving the gb12 in a 1 cube enclosure, it still has more output from 200hz down to 0hz.
> TLDR: learning how to actually use the modeling software and understanding what you are looking at is important.
> ...


You should look at the CSS Audio SDX12's, lower inductance, a bit different specs, but roughly the same power handling and output as Brahma's. SHOP | css-audio
Full disclosure: 1 of those reviews is mine.


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## SkizeR (Apr 19, 2011)

MF Toker said:


> What don't you like about the W7? Haven't heard one personally but have read many positive reviews but I'm pretty skeptical of the average expectation.. most people are easily impressed.
> 
> Saw earlier that you're not a fan of their amps.


The more experience I get with JL, the less I like how most of their equipment sounds. The W7's just don't sound all that accurate. I think their shallow subs sound better than their regular subs.


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## SkizeR (Apr 19, 2011)

ckirocz28 said:


> You should look at the CSS Audio SDX12's, lower inductance, a bit different specs, but roughly the same power handling and output as Brahma's. SHOP | css-audio
> Full disclosure: 1 of those reviews is mine.


I have tuned cars with them. They're sweet.


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## ckirocz28 (Nov 29, 2017)

Jahuntley79 said:


> Thanks, Nick. I was hoping you would respond. Here is an example of how small of a world we live in, guess who built the enclosure and installed my GB12 last year, Matt K. Hope you guys are doing well.
> 
> Now I’m leaning towards the Brahma. Being able to get by with a smaller enclosure is a big plus and it’s fun to try out a different sub.


Check these out before you go with a Brahma, almost the same, lower inductance. They are built in China if that matters to you, Brahma's are American made.
Forgot the link SDX12








SHOP | css-audio







www.css-audio.com


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## SkizeR (Apr 19, 2011)

ckirocz28 said:


> Check these out before you go with a Brahma, almost the same, lower inductance. They are built in China if that matters to you, Brahma's are American made.
> Forgot the link SDX12
> 
> 
> ...


you just said that and I commented that I have used them.. lol


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## ckirocz28 (Nov 29, 2017)

SkizeR said:


> I have tuned cars with them. They're sweet.


You can't beat the pre-order deal they had either, I believe it was $279.99 each, shipped.


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## ckirocz28 (Nov 29, 2017)

SkizeR said:


> you just said that and I commented that I have used them.. lol


That one was for @Jahuntley79.


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## Old'sCool (May 16, 2021)

I recently bought a pair of Kappa 1200W subs as "temporary" replacements for my older 10 inch PG subs. Though I'm swapping in an IB 15 with an aperiodic membrane, I have to say, the Kappa 1200W is no joke. They are astonishingly cheap, as well. 

If the box for a pair of 12s wasn't consuming 1/3 of my trunk, the Kappas would stay.

I've had JLs, JBL 1500GTIs, JBL 1200GTIs, Phoenix Gold (old school) 10s and 12s, MTX, OZ, Strokers, and even a Velodyne 12. The Kappas have more accurate bass than almost all of the above, only rivalled by the JBL 1500GTI (which was in a $2000 aperiodic setup) and the Velodyne 12, which was a $500+ woofer, running off a $1000 Zed amp.

I highly recommend the Kappa 1200W. Hell, worst-case, you're out $106 if you don't like it.

I guess after 30+ years of installing and dropping "mad coin," I'm getting more frugal. That said, the Kappas are running off an LC-1.1500, and will not only rattle your eyeballs with rap, they will soothe your soul with string bass and jazz, etc.


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## Thomasluke7899 (Jan 4, 2020)

Old'sCool said:


> I recently bought a pair of Kappa 1200W subs as "temporary" replacements for my older 10 inch PG subs. Though I'm swapping in an IB 15 with an aperiodic membrane, I have to say, the Kappa 1200W is no joke. They are astonishingly cheap, as well.
> 
> If the box for a pair of 12s wasn't consuming 1/3 of my trunk, the Kappas would stay.
> 
> ...


I'm using two 8s right now. Ported in 1.4 at 34 and they are better than the type r 8s I loved in 2012.


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## Bass Face (May 31, 2021)

ckirocz28 said:


> Nothing wrong at all with the Audiofrog stuff, but they are definitely NOT a bang-for-the-buck item.
> Regarding your friend's comparison, Audiofrog's subs are more sensitive than Brahma's, so with the same wattage the GB12 always wins. Here's where the fun starts, feed them both 2000 watts, the GB12 goes up in smoke and the Brahma 12 kicks your ass and begs for more while remaining as clean as the GB12 and delivering 1-2 more db than the GB12 can muster.
> GB12 $600
> Brahma 12 $500
> To be fair, amplification included, they are pretty much about the same value, unless you want that extra loudness, then the Brahma wins.


Thats what I love about the GB, the sensitivity rating. They can do significantly more with less. Can the Brahma get a few Decibal louder with more power and not blow up, absolutely. For me personally, I will likely never drive 2k watts into a sub. I just don’t see the value at that point. And to be honest, I think the GB can only do about 800watts rms. 1k would probably make it explode. Still, GB one of my favorite subs. I run two of them now sealed box. The accuracy and equal parts slam is mind blowing.

Not sure if op stated, but will he be running 2k of juice to a sub?


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## SkizeR (Apr 19, 2011)

Bass Face said:


> Thats what I love about the GB, the sensitivity rating. They can do significantly more with less. Can the Brahma get a few Decibal louder with more power and not blow up, absolutely. For me personally, I will likely never drive 2k watts into a sub. I just don’t see the value at that point. And to be honest, I think the GB can only do about 800watts rms. 1k would probably make it explode. Still, GB one of my favorite subs. I run two of them now sealed box. The accuracy and equal parts slam is mind blowing.
> 
> Not sure if op stated, but will he be running 2k of juice to a sub?


I've had to have conversations with past customers to not get their expectations out of wack regarding this exact thing... Beware of the sensitivity ratings listed on the Audiofrogs site. You need to understand how sensitivity is derived and what can affect it. Audiofrogs site shows 95db for the GB12d2..... at 1 ohm with 2.83v. That is NOT standard. There are two typical ways to measure sensitivity. One being at 2.83v, and the other being 1 watt. With 8 ohm drivers (which used to be essentially standard), they are the same. But when you start dropping impedance, 2.84v changes. at 4 ohms, 2.83v is 2 watts. Frogman is hoping that people like you read this sensitivity spec of his and don't think anything of it, since the GB12d2 is measured at 2.83v with the coils in parallel, they're getting 8 watts. No shiit it looks like it's high efficiency lol. In an apples-to-apples comparison vs say, the Adire Brahma 12d2 (which is 84.6db at 1 watt wired in series), the GB12D2 would come in at 86db at 1 watt wired in series. You can use TS parameters to calculate sensitivity as well. According to WinISD, GB12d2 comes in at 86, and the Adire comes in at 85...

Lets also not forget the GS8 sensitivity debacle lol


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## Jahuntley79 (Jan 5, 2020)

SkizeR said:


> I've had to have conversations with past customers to not get their expectations out of wack regarding this exact thing... Beware of the sensitivity ratings listed on the Audiofrogs site. You need to understand how sensitivity is derived and what can affect it. Audiofrogs site shows 95db for the GB12d2..... at 1 ohm with 2.83v. That is NOT standard. There are two typical ways to measure sensitivity. One being at 2.83v, and the other being 1 watt. With 8 ohm drivers (which used to be essentially standard), they are the same. But when you start dropping impedance, 2.84v changes. at 4 ohms, 2.83v is 2 watts. Frogman is hoping that people like you read this sensitivity spec of his and don't think anything of it, since the GB12d2 is measured at 2.83v with the coils in parallel, they're getting 8 watts. No shiit it looks like it's high efficiency lol. In an apples-to-apples comparison vs say, the Adire Brahma 12d2 (which is 84.6db at 1 watt wired in series), the GB12D2 would come in at 86db at 1 watt wired in series. You can use TS parameters to calculate sensitivity as well. According to WinISD, GB12d2 comes in at 86, and the Adire comes in at 85...
> 
> Lets also not forget the GS8 sensitivity debacle lol


I’m thinking of buying the adire Brahma in the adire sealed enclosure (its 1.0 cu ft). Using a mosconi pro 5/30 I’ll have 660w at 4ohms or 1060w at 2ohms (the Brahma is rated 1000w rms). Do you think that is sufficient power based on your work with the Brahma?

I really appreciate the input, thank you.


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## Jahuntley79 (Jan 5, 2020)

Ps the post on GB12 sensitivity is very interesting. Without skizer’s insight, I would have assumed it was 95db at 1w and all else equal would have used that as part of my rationale to get another GB12.


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## SkizeR (Apr 19, 2011)

Jahuntley79 said:


> Ps the post on GB12 sensitivity is very interesting. Without skizer’s insight, I would have assumed it was 95db at 1w and all else equal would have used that as part of my rationale to get another GB12.


Marketing, baby!

But still cant take away from how they sound. They're good.


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## Jahuntley79 (Jan 5, 2020)

SkizeR said:


> Marketing, baby!


Totally, but I’ve always thought Andy was one of the more honest and straightforward people in the industry. That’s very interesting.


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## daloudin (Nov 2, 2020)

Jahuntley79 said:


> Totally, but I’ve always thought Andy was one of the more honest and straightforward people in the industry. That’s very interesting.


AF isn't the only one doing this... ALWAYS look at the way sensitivity is rated. Dayton got burned for doing this years ago when they first got in to the Big Excursion drivers. All the guys using PA Subs in huge boxes with 101dB sensitivity bought 15" Ultimaxes thinking their 2 Ohm Parallel rating was the same as the 18" 8 Ohm SVC rating and got pissed...

But 2 x GB12 is usually more than enough for all but the bassheads... 🤘

Yes, 1,060 Watts from Mosconi will be perfect for a Brahma.


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## Bass Face (May 31, 2021)

SkizeR said:


> I've had to have conversations with past customers to not get their expectations out of wack regarding this exact thing... Beware of the sensitivity ratings listed on the Audiofrogs site. You need to understand how sensitivity is derived and what can affect it. Audiofrogs site shows 95db for the GB12d2..... at 1 ohm with 2.83v. That is NOT standard. There are two typical ways to measure sensitivity. One being at 2.83v, and the other being 1 watt. With 8 ohm drivers (which used to be essentially standard), they are the same. But when you start dropping impedance, 2.84v changes. at 4 ohms, 2.83v is 2 watts. Frogman is hoping that people like you read this sensitivity spec of his and don't think anything of it, since the GB12d2 is measured at 2.83v with the coils in parallel, they're getting 8 watts. No shiit it looks like it's high efficiency lol. In an apples-to-apples comparison vs say, the Adire Brahma 12d2 (which is 84.6db at 1 watt wired in series), the GB12D2 would come in at 86db at 1 watt wired in series. You can use TS parameters to calculate sensitivity as well. According to WinISD, GB12d2 comes in at 86, and the Adire comes in at 85...
> 
> Lets also not forget the GS8 sensitivity debacle lol


Ironically enough I’m thankful for Frogman aka Andy for the information he provides to “people like like me.” The end result being he’s happy with his design and I’m a happy user of his products. Everyone makes out in this situation. That being said, even at 86, it’s leans on being the more efficient sub. And it definitely doesn’t need 1k or 2k of sauce to get rowdy. 

As far as those GS8, dem things clap.


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## MF Toker (Jan 10, 2011)

SkizeR said:


> I've had to have conversations with past customers to not get their expectations out of wack regarding this exact thing... Beware of the sensitivity ratings listed on the Audiofrogs site. You need to understand how sensitivity is derived and what can affect it. Audiofrogs site shows 95db for the GB12d2..... at 1 ohm with 2.83v. That is NOT standard. There are two typical ways to measure sensitivity. One being at 2.83v, and the other being 1 watt. With 8 ohm drivers (which used to be essentially standard), they are the same. But when you start dropping impedance, 2.84v changes. at 4 ohms, 2.83v is 2 watts. Frogman is hoping that people like you read this sensitivity spec of his and don't think anything of it, since the GB12d2 is measured at 2.83v with the coils in parallel, they're getting 8 watts. No shiit it looks like it's high efficiency lol. In an apples-to-apples comparison vs say, the Adire Brahma 12d2 (which is 84.6db at 1 watt wired in series), the GB12D2 would come in at 86db at 1 watt wired in series. You can use TS parameters to calculate sensitivity as well. According to WinISD, GB12d2 comes in at 86, and the Adire comes in at 85...
> 
> Lets also not forget the GS8 sensitivity debacle lol


It is odd, maybe some what deceptive. If you look at the manual it has the predicted response around 86db and the response with cabin gain shows it closer to that 92db at 1 watt figure. I think it should be noted as in car sensitivity or they should just rate them at 86db


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## MF Toker (Jan 10, 2011)

Jahuntley79 said:


> Ps the post on GB12 sensitivity is very interesting. Without skizer’s insight, I would have assumed it was 95db at 1w and all else equal would have used that as part of my rationale to get another GB12.


Always best to model up all your options. If the T/S specs are accurate then it gives you a solid idea of how they compare in sensitivity and response.


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## Jahuntley79 (Jan 5, 2020)

Just to be clear on my prior comments, I loved my GB12 and wouldn’t be in the market for another sub if someone didn’t steal mine. But, I’m also excited to try something new.

My build also has two JL tw3 10s and a focal 8” under seat sub. The GB12 augmented the JLs and definitely added to the overall sq. That is something that I should have mentioned up front. I just went back to the first post and included my current build.


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## Bass Face (May 31, 2021)

MF Toker said:


> It is odd, maybe some what deceptive. If you look at the manual it has the predicted response around 86db and the response with cabin gain shows it closer to that 92db at 1 watt figure. I think it should be noted as in car sensitivity or they should just rate them at 86db


This sounds right. They are dumb loud, clean, and effortless in their playback.


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## Bass Face (May 31, 2021)

Jahuntley79 said:


> Just to be clear on my prior comments, I loved my GB12 and wouldn’t be in the market for another sub if someone didn’t steal mine. But, I’m also excited to try something new.
> 
> My build also has two JL tw3 10s and a focal 8” under seat sub. The GB12 augmented the JLs and definitely added to the overall sq. That is something that I should have mentioned up front. I just went back to the first post and included my current build.


I didn't know you had other JL drivers. Either way very cool setup. Regardless what was said here, the W7 is still a very good subwoofer. It is one of the old school subs that has done very well through the years. I only bring this up because you have other JL gear and it all will play well together. 

But that GB still one of the best, prob why you love them.


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## daloudin (Nov 2, 2020)

Jahuntley79 said:


> In my case, I will “only” have 1k watts. I know it is ample for a GB12, but I’d kind of like to try something different.
> 
> Has anyone used two or more of the following? In my case it will be driven by 660w at 4ohms or [email protected] in a sealed enclosure.
> 
> ...


Just to add to the confusion here's a WinISD model run.

All subs in 1 cuft sealed (most want bigger resulting in the upper bass Hi-Qts bump, other than SQL and Brahma but staying at 1 cuft keeps all contenders below xmax) and all DVC at 1,000 W and SVC at 660 W with cabin gain modeled:









If you've got room for a bigger box then let me know cause some of these want much more box (Raven, Morel and Dynaudio especially.) But for 1 cubic foot and 1kW the Brahma is the model winner.


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## Jahuntley79 (Jan 5, 2020)

daloudin said:


> Just to add to the confusion here's a WinISD model run.
> 
> All subs in 1 cuft sealed (most want bigger resulting in the upper bass Hi-Qts bump, other than SQL and Brahma but staying at 1 cuft keeps all contenders below xmax) and all DVC at 1,000 W and SVC at 660 W with cabin gain modeled:
> View attachment 309233
> ...


Thank you! I’m more and more convinced the Brahma is the right choice. Given space constraints, id like to keep the volume close to 1 cu ft.


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## daloudin (Nov 2, 2020)

Jahuntley79 said:


> Thank you! I’m more and more convinced the Brahma is the right choice. Given space constraints, id like to keep the volume close to 1 cu ft.


With "ONLY" 1,000 Watts (if you had more then the SQL becomes a better choice) and limited space then the Brahma would be my 1st choice easily.


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## Jahuntley79 (Jan 5, 2020)

Thanks to everyone that contributed to the thread. I ordered an adire Brahma in a 1 cu ft sealed adire made enclosure. Perhaps more importantly, I’m having an alarm installed this week (before installing the new sub).


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## Bass Face (May 31, 2021)

Jahuntley79 said:


> Thanks to everyone that contributed to the thread. I ordered an adire Brahma in a 1 cu ft sealed adire made enclosure. Perhaps more importantly, I’m having an alarm installed this week (before installing the new sub).


Congrats! Keep us posted on how you like it and pictures.


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## Hypefxx (Apr 19, 2020)

I have the gb12 ported on a JL 1200 slash and it sounds great. Nice beautiful sq but gets nice and loud too.

Also own a tumult as well. Great sound but lacks the upper kick compared to the frog. Massive lows though. I guess that's a tradeoff.

I haven't tried sealed yet.


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## LBaudio (Jan 9, 2009)

SkizeR said:


> I've had to have conversations with past customers to not get their expectations out of wack regarding this exact thing... Beware of the sensitivity ratings listed on the Audiofrogs site. You need to understand how sensitivity is derived and what can affect it. Audiofrogs site shows 95db for the GB12d2..... at 1 ohm with 2.83v. That is NOT standard. There are two typical ways to measure sensitivity. One being at 2.83v, and the other being 1 watt. With 8 ohm drivers (which used to be essentially standard), they are the same. But when you start dropping impedance, 2.84v changes. at 4 ohms, 2.83v is 2 watts. Frogman is hoping that people like you read this sensitivity spec of his and don't think anything of it, since the GB12d2 is measured at 2.83v with the coils in parallel, they're getting 8 watts. No shiit it looks like it's high efficiency lol. In an apples-to-apples comparison vs say, the Adire Brahma 12d2 (which is 84.6db at 1 watt wired in series), the GB12D2 would come in at 86db at 1 watt wired in series. You can use TS parameters to calculate sensitivity as well. According to WinISD, GB12d2 comes in at 86, and the Adire comes in at 85...
> 
> Lets also not forget the GS8 sensitivity debacle lol


finally somebody said that clear. People just cant read specs correct and might be wowed by the specs which are set to look super good,...the same with amp ratings/power supply and distortion


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## audiocholic (Dec 5, 2016)

has anyone here used a high end DLS? I have used a significant number of SQ Subs and the DLS Nordica 10i without a doubt is the winner for me.


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## LBaudio (Jan 9, 2009)

heard a lot of good things regarding DLS nordica 10 sub


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## audiocholic (Dec 5, 2016)

LBaudio said:


> heard a lot of good things regarding DLS nordica 10 sub


I have had the pleasure to own/use (not to mention all in the very same Hatchback I have)

1) JL W7
2) JL W6
3) JL TW3
4) Focal 33v2 Polyglass
5) Focal Kx33
6) Morel Ultimo (older edition)
7) Rainbow Vanadium
8) DLS Nordica


for me almost all these drivers lacked something one way or another (though I believe the Vanadium was great aswell it was definatley showing its age) except for the DLS Nordica, its did everything soo soo well.


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## Granite (Jun 3, 2020)

daloudin said:


> Just to add to the confusion here's a WinISD model run.
> 
> All subs in 1 cuft sealed (most want bigger resulting in the upper bass Hi-Qts bump, other than SQL and Brahma but staying at 1 cuft keeps all contenders below xmax) and all DVC at 1,000 W and SVC at 660 W with cabin gain modeled:
> View attachment 309233
> ...


I appreciate you doing these winisd graphs - they really provide an objective, numerical comparison that imparts some semblance of what the differences between the subs are.

That said, I’m not sure how to reconcile these graphs with actual real world listening. I have 12 inch versions of the w6, w7, and Brahma and they’re all in identical 1.1 cf boxes from adire.

The Brahma (@ 1100w 4 ohm) and w6 (@ 550w 8 ohm) are virtually indistinguishable from each other - the Brahma digs a little lower, the w6 has a cleaner sound from 40hz up. 

The w7 (@ 1100w 3 ohm) - and I can’t stress this enough - absolutely obliterates both of those in spl, and is as good or better sq throughout the passband. Just night and day.


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## daloudin (Nov 2, 2020)

Granite said:


> I appreciate you doing these winisd graphs - they really provide an objective, numerical comparison that imparts some semblance of what the differences between the subs are.
> 
> That said, I’m not sure how to reconcile these graphs with actual real world listening. I have 12 inch versions of the w6, w7, and Brahma and they’re all in identical 1.1 cf boxes from adire.
> 
> ...


There's the rub - WinISD can give you an "idea" of how subs will react and is an invaluable tool when looking for a sub to fit a particular install (limited size or power) but can only begin to simulate what the sub will sound like once installed. But in your particular example the W6 and Adire would be nearly flat 0.7 Q alignments where that's an undersized Hi-Qts install for a W7 so once cabin gain is added it was probably one of those magic moments where the box gain and cabin gain combined to create exactly what you wanted. 

Personally, the W7 sound (and this is just me) it's not what I'm looking for... they are immensely accurate and great for metal heads or anyone who needs that full on vision blurring chest slam, but they lack finesse and other less tangible harmonics that I believe are related to being what I call hyperactive. It's not bad - just different. Additionally when pushed they reach thermal compression quicker than other more classic designs like the Adire or Stereo Integrity. I'm not refuting anyone who says they're capable of SQ as they admirably overcome a lot of the boominess inherent in most Hi-Qts installs but it's not my cup of tea. Then once you factor in the price they get relegated to the "oh you already own them so we'll work with that..." but I rarely recommend an initial purchase. 

Sent from my SM-G965U using Tapatalk


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## SkizeR (Apr 19, 2011)

LBaudio said:


> finally somebody said that clear. People just cant read specs correct and might be wowed by the specs which are set to look super good,...the same with amp ratings/power supply and distortion


Yup, just what the marketing department wants lol. Again, I take nothing away from those subs as they sound incredible, but being able to watch this without having to worry about andy calling me and bitching is great lol


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## ckirocz28 (Nov 29, 2017)

Jahuntley79 said:


> Totally, but I’ve always thought Andy was one of the more honest and straightforward people in the industry. That’s very interesting.


He's just doing what almost everyone else does. But this issue has been discussed in other threads here. At one point, Andy had changed to the 1 watt at 1 meter spec or at least added it in response to one of those threads.


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## cman (Aug 24, 2020)

LBaudio said:


> finally somebody said that clear. People just cant read specs correct and might be wowed by the specs which are set to look super good,...the same with amp ratings/power supply and distortion


don’t even get me started on linear excursion…gah!! I wish the whole world used klippel specs. Even voice coil overhang is not sufficient… there are drivers with 16mm tall voice coils that end up having more distortion free excursion than drivers with 20mm tall voice coils…

if everyone else is doing it does it make it right? I say put real numbers and even write a note saying “most manufacturers are stating their sensitivity or excursion etc this way” “ours is measured this way..” etc… do not just use whatever you need to in order to get the highest number… it takes away from the brands integrity in my opinion… like amps with signal to noise referenced to full power instead of one watt at 4 ohms… such a load of crap..


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## MF Toker (Jan 10, 2011)

cman said:


> don’t even get me started on linear excursion…gah!! I wish the whole world used klippel specs. Even voice coil overhang is not sufficient… there are drivers with 16mm tall voice coils that end up having more distortion free excursion than drivers with 20mm tall voice coils…
> 
> if everyone else is doing it does it make it right? I say put real numbers and even write a note saying “most manufacturers are stating their sensitivity or excursion etc this way” “ours is measured this way..” etc… do not just use whatever you need to in order to get the highest number… it takes away from the brands integrity in my opinion… like amps with signal to noise referenced to full power instead of one watt at 4 ohms… such a load of crap..


In test that I've seen it's usually 50-75% of what's advertised. I always shoot for reaching half excursion at max output when I'm looking into using any particular driver.


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## LBaudio (Jan 9, 2009)

SkizeR said:


> Yup, just what the marketing department wants lol. Again, I take nothing away from those subs as they sound incredible, but being able to watch this without having to worry about andy calling me and bitching is great lol


no one said that subs are poor performers,...I would like to get my hands on one due to many tests and opinions I read over the time, but finding one in Europe is quite a task. marketing ******** is something other. high numbers sells products, and that is something that many dont understand and many fall for this kind of marketing...bigger is better, lol.


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## Bass Face (May 31, 2021)

OP, did you get your sub yet!? Pics and thoughts if possible.


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## Jahuntley79 (Jan 5, 2020)

Not yet. I ordered it about a week ago. I’ll post my thoughts when it is installed and my tune is updated.


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## gwalsh (Sep 15, 2013)

My purely subjective response (for what it's worth): I have had the pleasure of using the following SQ subs, sealed enclosures, in the following order of my Kia build, all powered by an ARC X2 1100.1:

Image Dynamics IDMax12;
JLAudio 10W7;
AF GB12;
Adire Brahma MK2 12.

IDMax & JLW7 both seemed to be the loudest and hit the hardest. GB12 & Brahma were definitely the most musical and blended seamlessly, providing me subjectively with just what I want in a Sub. The Brahma is my current favorite and, after breaking in (took a while), will stay in my Kia for a while. Next logical upgrade for me would be to provide more power with a new sub amplifier.


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## Jahuntley79 (Jan 5, 2020)

@gwalsh Thanks for sharing that is great to hear.


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## 156546 (Feb 10, 2017)

We rate sensitivity at 2.83V because this IS engineering standard. The reason it's an engineering standard is because drivers are often driven by the same amplifier and an amplifier is a VOLTAGE source. When you're comparing one driver to another and they are going to be driven by the same amplifier, then this makes it REALLY simple to see which one will play louder. This is ESPECIALLY helpful for midrange, midbass and tweeters for use with passive crossovers. 

There are a bunch of ways to manage how loudly a speaker will play. If you look carefully at the impedance for GB speakers, you'll see that the GB25 has a LOWER impedance than the GB60 for this VERY reason--to increase the voltage sensitivity so that the output when driven with the same amp is within a dB or so of a GB60. The tweeters were designed to be about 6dB louder than each of those, so that when used with a passive crossover, there's an ability to set the tweeter level higher than the reference level of the mid and midbass. 

All sensitivity ratings are mid band ratings, and we use subwoofers in the stopband--where the output is rolling off. Midband for a sub would be above that band of frequencies. So, the sensitivity rating of a subwoofer isn't a reliable way to determine how loudly the sub is going to play when used with a low pass filter. 

This is why the owner's manual for all the GB subwoofers includes a frequency response chart for the woofer in the recommended boxes at 2.83V and also includes a model of an in-car response that's based on the average of transfer function measurements made in about 30 different cars. 

There's no intent to deceive here.


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## 156546 (Feb 10, 2017)

SkizeR said:


> The GB12 is one of my favorite subs to date, but this is just not correct or the right way to look at things.
> 
> 1) Modeling software is ONLY used to calculate how the driver behaves in certain enclosures at and around its resonant frequency. It does not tell you how it'll actually sound overall or how they will behave in the long run. No transient response, distortion, power compression, reliability, etc.. none of that is factored into modeling. You can manipulate modeling to make one look better than the other if you want, but looking at the whole picture, someone who knows what they're looking at can tell that while the GB12 caps out with 1000 watts in a 1 cube enclosure, the Brahma can still match (actually, do just a hair better) it in output and low-frequency extension in the same enclosure, while still having 8.25mm more linear excursion to go. So if you really wanted to, you can throw another 1k of power at it and beat it in all regards if needed. After modeling, accounting for xmax to be reached at 20hz, the brahma is capable of 4db more output from 100hz down, and match output at 180hz. Now messing with it a bit, this same situation but sticking the brahma in a 0.5 cube enclosure while leaving the gb12 in a 1 cube enclosure, it still has more output from 200hz down to 0hz.
> TLDR: learning how to actually use the modeling software and understanding what you are looking at is important.
> ...



Nick, this is patently untrue regarding the computer modeling of speakers. WinISD may not do it, but many other programs can, so long as distortion measurements at several power levels are loaded, so long as voice coil thermal data is loaded and so long as coil height and magnet dimension parameters are included. LEAP has been able to do some of this and has been able to do it since it was changed to a windows program more than 20 years ago.

The Brahma is also a nice sub.

Any speaker designer worth his salt can look at a speaker, look at a few measurements and the parameters and know pretty quickly what the intended use is and what it will sound like. What he may not be able to determine is what it will sound like if it is used in a way it wasn't intended to be used and especially if driven with WAY more power than it's designed for.


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## ckirocz28 (Nov 29, 2017)

GotFrogs said:


> All sensitivity ratings are mid band ratings, and we use subwoofers in the stopband--where the output is rolling off. Midband for a sub would be above that band of frequencies. So, the sensitivity rating of a subwoofer isn't a reliable way to determine how loudly the sub is going to play when used with a low pass filter.


Can you explain this^ in a bit more detail? Are the frequencies used falling outside a typical subwoofer's pass band?


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## 156546 (Feb 10, 2017)

ckirocz28 said:


> Can you explain this^ in a bit more detail? Are the frequencies used falling outside a typical subwoofer's pass band?


Loudspeaker sensitivity (for DRIVERS, not necessarily for loudspeaker SYSTEMS) is calculated from the efficiency of the speaker which is calculated from the thiele and small parameters.

Efficiency is this:










Sensitivity is calculated from efficiency this way (grabbing pictures is much easier than typing formulae:










So, a speaker that isn't a subwoofer is intended to be used ABOVE resonance and in the region between it and where it rolls off at high frequency or the point at which dispersion begins to narrow (depending on the intended use of the speaker system--PA and near field monitors have different design goals--for near field, we don't care so much about off axis response, for example).

For a GB60, for example, we'd use it between 80 Hz or so and about 3kHz so long as we have a tweeter that can play that low. Optimally, we'd try to cross at about 1k. Here:










So, our midband sensitivity is anywhere the speaker has relatively flat response. The calculated parameter matches pretty closely with the MEASURED sensitivity, but the measurement always has peaks and dips--these are caused by the cone changing shape as it moves back and forth.










Now, for a subwoofer, this is different. Midband sensitivity ([email protected] or 1W/1M or whatever) is here:










But that's not where we use the sub. We use a low pass filter, like this 24dB/oct Linkwitz Riley filter








:

So, if you look carefully, the frequency at which the output is highest is about 40Hz and it isn't 95dB. That's because the response was already rolling off below 60Hz before we applied the low pass filter.

But, when we put it in the car, this is what happens (the purple line). This model is based on an average over 30 or so measurements, so yours is going to look slightly different, but not much different unless you drive a Smart for Two or a school bus.










And if you look carefully at the resulting curve, you'll see that it very closely matches the low frequency part of the target curve that I recommend.

I sometimes get whacked by the uber DIYers because they think that all sealed boxes should have a Qtc of 0.707 so "Audiofrog speakers really need bigger boxes". This isn't really how it works in a car because we cross below Fc, so there really isn't a Qtc. I start with an in car target and then I choose a box volume that makes sense (for sealed and vented boxes) and then I design a woofer to hit the target in the chosen box.

Maybe that's why they sound good.


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## ckirocz28 (Nov 29, 2017)

GotFrogs said:


> Loudspeaker sensitivity (for DRIVERS, not necessarily for loudspeaker SYSTEMS) is calculated from the efficiency of the speaker which is calculated from the thiele and small parameters.
> 
> Efficiency is this:
> 
> ...


So boiling all of that down, the sub's sensitivity is measured at a frequency above where they are generally playing, so that particular spec doesn't reflect real world usage, plus it gets really different with cabin gain. Correct?


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## ckirocz28 (Nov 29, 2017)

GotFrogs said:


> Loudspeaker sensitivity (for DRIVERS, not necessarily for loudspeaker SYSTEMS) is calculated from the efficiency of the speaker which is calculated from the thiele and small parameters.
> 
> Efficiency is this:
> 
> ...


By the way, thanks!


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## Bass Face (May 31, 2021)

Great Post @GotFrogs 
I'm glad this explanation is outside of the realm of "marketing" as someone posted above. Clearly continued education helps everyone instead of labeling just people/users as "people like you". Thank you again. I am and will continue to be an AF user for a very long time.


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## SkizeR (Apr 19, 2011)

but your models are still done in 2.83v at 1 ohm. soooo..?


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## 156546 (Feb 10, 2017)

ckirocz28 said:


> So boiling all of that down, the sub's sensitivity is measured at a frequency above where they are generally playing, so that particular spec doesn't reflect real world usage, plus it gets really different with cabin gain. Correct?


Yes.


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## 156546 (Feb 10, 2017)

SkizeR said:


> but your models are still done in 2.83v at 1 ohm. soooo..?


These are, but even this spreadsheet allows modeling at additional power and plots the resulting excursion over frequency. A good designer can use that to determine the amount of power that will cause the coil to reach the edge of the gap--and that's the point at which distortion begins to rise at low frequencies around resonance. Knowing about the construction of the motor and the suspension makes is relatively simple to determine which kind of distortion will rise and by how much--even order or odd order. 

Odd order distortion is the one that really sounds bad--like a mechanical problem--is caused by behavior that's symmetrical with forward and rearward movement. For a woofer with a motor designed to shape the fringe fields similarly above and below the gap, this is MOSTLY caused by the coil moving past the edge of the gap, or inextreme cases, approaching the opposite edge of the gap and we hear that as a "thud thud thud". Other actual mechanical sounds we don't like often happen at the limits of mechanical excursion--the spider flattens or the surround reaches the end of its travel. Usually, the spider is designed to slow the cone as it nears the voice coil limit and the surround is designed to stop it if it moves past the spider's limit. Making sure these forces are complementary is a really important part of desiging the suspension of a subwoofer--get this wrong and the sub's zero position in between the excusrion limits will move forward or rearward. This is easily seen using a stroboscope, for example. Klippel shows this behavior in the compliance and motor force over excursion graphs and recommends a coil offset to compensate.

Even order distortion is caused by NON symmetrical behavior with forward and rearward movement. This is SOMETIMES the result of a motor in which the fringe fields have very different shapes above and below the gap--one of the benefits of a well-executed XBL design, for example is that the fringe fields don't really come into play until the end of excursion--as in a design without an extended polepiece, or a T-shaped polepiece. The spider is the biggest culprit here because spiders often exert different force during forward and rearward movement. Cupped spiders--the ones in which there is a big vertical wall at the outside perimeter--often do this because the base of that edge becomes a hinge and moves more easily in one direction than another. 

All of this is well described in distortion graphs that include 2nd and 3rd order plots--a designer can look at these at several power levels and understand what's happening and this is precisely how this was done before the Klippel machine. Of course, there were MANY great speakers designed before the Klippel using these measurements, anechoic chambers, laser vibrometers, stroboscopes and search coils. Klippel makes the job much faster for speaker designers. 

So what really happens in a sub at higher power and what might we hear in the way of changing frequency response? As the coil heats, its resistance increases a little bit. That causes a little less current to flow through the coil. The slightly reduced motor force raises the Q a little bit. In a speaker like a home speaker where the low pass filter is MUCH higher--for example, the speakers I use at home has a 15" woofer that plays up to 1k--this can change the sound of the speaker by reducing low bass slightly and increasing the output around Fc. 

In a car with a low pass of 60Hz, the sound is not changed significantly--we cross below Fc so the Q doesn't have this same effect. We just get a little less output than we would without this power compression. The rolloff at low frequencies becomes slightly steeper. 

This is all that happens to the frequency response, and it's not objectionable--or even audible--in subs designed to handle a lot of power. 

Of all the speakers in a system that can be adequately characterized from a performance standpoint by the numbers, subs are the ones. We use them within their piston range, so we don't really need to characterize the changing shape of the cone that creates peaks and dips in the frequency response. Occasionally, this is a problem near the band of frequencies in which we use them--especially as a midbass driver, but there's something else that prevents even that from being an audible problem--we sit in the near field in a car at low frequencies and those low frequency anomalies don't show up in a near field measurement. They do show up in a far field measurement.This is one of the cases in which understanding the measurement and the use helps us know what to measure and how and what is and isn't a concern in practical use. 

The higher the frequency the more difficult the design and development and the less likely we are to be able to characterize the sound of speaker using the simple lumped parameter modeling that Thiele and Small parameters describe. That, however, doesn't mean designing speakers is some kind of magic for which only subjective analysis is useful. It just means that OTHER methods of characterization and modeling are more useful, especially to a designer who knows how this stuff works. Since most every peak and every dip in the frequency response is the result of some cone mode or dustcap/coil behavior, we can go back to the "old school" method of isolating a peak or a dip in a measurement and using some tool that allows us to view the behavior of the cone at that frequency and employ some counter measure--or we can use modeling software designed for these kinds of analyses--like FEA. 

Sometimes experience means that we don't have to do all of that if a potential problem is apparent. I know really good designers that can look at a speaker and say, "nope. That's not going to work and here's why" or "wow, that's a really good idea. I'd expect [enter some description of the likely performance benefit]". Similarly, I can look at speaker placement in a car before listening and have a pretty good idea of what the problems are going to be and I suggest placements to people based on this experience and also on a pretty good understanding of how this stuff works. That means that for me, cars are more similar than different and there are some performance aspects that can be adequately predicted. This is why the "all cars are different" justification falls flat with me. Of course there are some differences, but mostly they are similar. Making use of similarity and the fact that it makes prediction possible so we can deal with the small differences as necessary is really useful. 

If someone went to see a cardiologist and he, using his training and experience, diagnosed a problem for which a surgery was an appropriate intervention, and the patient said, "but all bodies are different", the doc would say the same thing--sure, there are some differences, but your heart mostly works like other hearts and it's in the same place as other hearts and it's about the same size. Recognizing these similarities makes determining the misbehavior possible. Asking, "But have you made a similar diagnosis in someone named George? Because my name is George" is akin to saying that a BMW is so different from a Mercedes that we cannot assign any similarity. And that's silly.


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## cman (Aug 24, 2020)

GotFrogs said:


> Nick, this is patently untrue regarding the computer modeling of speakers. WinISD may not do it, but many other programs can, so long as distortion measurements at several power levels are loaded, so long as voice coil thermal data is loaded and so long as coil height and magnet dimension parameters are included. LEAP has been able to do some of this and has been able to do it since it was changed to a windows program more than 20 years ago.
> 
> The Brahma is also a nice sub.
> 
> Any speaker designer worth his salt can look at a speaker, look at a few measurements and the parameters and know pretty quickly what the intended use is and what it will sound like. What he may not be able to determine is what it will sound like if it is used in a way it wasn't intended to be used and especially if driven with WAY more power than it's designed for.


I think alot of people including myself notice a difference in the XBL2 subs. They have such a flat linear BL curve that it takes some getting used to... Most subs I think when the BL shifts the Q also shifts if i am not mistaken..? It is one of those things on paper you think it would be great but you end up having people saying they do not sound the way they like a sub to sound..although i've heard people on both sides of the fence about this...




GotFrogs said:


> Loudspeaker sensitivity (for DRIVERS, not necessarily for loudspeaker SYSTEMS) is calculated from the efficiency of the speaker which is calculated from the thiele and small parameters.
> 
> Efficiency is this:
> 
> ...



I've noticed when i stick my sub (GB12) in too large of an enclosure the bass is not as "tight" is the best way i can describe it. When i put it in a smaller enclosure it seems to have a faster recovery from the transient bumps or peaks... Is this just the frequency response roll off changing from the enclosure volume or is this actually possible since the air acts as suspension on the subwoofer?


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## 156546 (Feb 10, 2017)

cman said:


> I think alot of people including myself notice a difference in the XBL2 subs. They have such a flat linear BL curve that it takes some getting used to... Most subs I think when the BL shifts the Q also shifts if i am not mistaken..? It is one of those things on paper you think it would be great but you end up having people saying they do not sound the way they like a sub to sound..although i've heard people on both sides of the fence about this...
> 
> 
> 
> ...


Putting it in a larger box just increases the low frequency output so that the response rises at low frequency in the car. What you hear as "tighter bass" is simply a different frequency response. If you use your equalizer to reduce the low bass from the larger box, it will sound the same as the smaller box. That's how this works at low frequencies.


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## 156546 (Feb 10, 2017)

Oh, and yes, a reduction in BL also increases the Qes which increases the Qts, which increases the Qtc, but I don't think that's what you're hearing because in a sealed box we usually cross below Fc anyway. I think the main benefit in an Xbl design that actually works is a reduction in distortion because Le is more constant over excursion. Not all Xbl designs do this in practice, though.


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## 156546 (Feb 10, 2017)

I also think that unless you're doing very careful blind comparisons between one sub and another sub in the same car, many of these suggestions about one versus another are mostly attributable to something in the system other than the subwoofer motor's design. We don't hear distortion at low frequencies very easily.


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## Hugs29 (Jan 30, 2021)

Which sub did you end up with? I'm in a similar situation.... I currently have a JLCLS110RGW7 which is a 10 inch w7 in a jl made sealed box. I'm looking for a SQ subwoofer that my mosconi pro 5/30 can power and was thinking of replacing my w7. I'm not into super loud bass but want nice clean bass. I have a vw golf r hatchback so I have decent size trunk I think . I'm running two way focal utopia m series speakers with a helix dsp ultra.


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