# isoberic strokers?



## NJPCRX (Jul 25, 2012)

Ok, I have 2 first gen stroker 18's. I have completed a system in my Hummer H3 that consists of one of the stroker 18's and 2 usa-400's, one per coil running at 4 ohm bridged (duel 4 ohm subs) I used both amps cause I have 2 matching ones. It sounds decent, but I was wondering if I can simply load the other stroker isoberic (clam-shell), and then bridge each us amp at 2 ohm to each sub? The box is built to spec for the one driver. With the other sub, i would double the power and double the drivers. Is it that simple, or am I missing something? What would be my gains and losses? Most of the negative stuff I hear about isoberic set-ups is the cost of the additional equiptment. I already have the stuff, so what could I expect from this? I guess I'm not clear on the box volume. I know the porting will stay the same. If I model it in WinIsd, the output on the graph is unchanged between 1 sub in my enclosure, and 2 subs isoberic, which I thought was strange. I'm gonna post this in the old school section as well, so cut me a break,


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## NJPCRX (Jul 25, 2012)

*isoberic stroker set-up*

Ok, I have 2 first gen stroker 18's. I have completed a system in my Hummer H3 that consists of one of the stroker 18's and 2 usa-400's, one per coil running at 4 ohm bridged (duel 4 ohm subs) I used both amps cause I have 2 matching ones. It sounds decent, but I was wondering if I can simply load the other stroker isoberic (clam-shell), and then bridge each us amp at 2 ohm to each sub? The box is built to spec for the one driver. With the other sub, i would double the power and double the drivers. Is it that simple, or am I missing something? What would be my gains and losses? Most of the negative stuff I hear about isoberic set-ups is the cost of the additional equiptment. I already have the stuff, so what could I expect from this? I guess I'm not clear on the box volume. I know the porting will stay the same. If I model it in WinIsd, the output on the graph is unchanged between 1 sub in my enclosure, and 2 subs isoberic, which I thought was strange. I posted this in the technical section also...


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## smgreen20 (Oct 13, 2006)

*Re: isoberic stroker set-up*

There's no gain but for sub control. Sealed,it'll cut the box volume in half, ported I'm not sure of. You won't gain any additional output if that's what you're after. That's another reason people say it's a waste ofmoney.


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## splaudiohz (Apr 1, 2011)

*Re: isoberic stroker set-up*

I personal love the Isobaric boxes....


Isobaric loudspeaker - Wikipedia, the free encyclopedia

JL Audio » header » Support » Tutorials » Tutorial: Isobaric Enclosure Characteristics



> Isobaric - Dual Drivers
> 
> Basic Theory
> 
> ...


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## squeak9798 (Apr 20, 2005)

*Re: isoberic stroker set-up*

Isobaric

According to that website isobaric push-pull doesn't have the same distortion canceling as a standard push-pull. 

If that is indeed the case, then the only advantage to ISO is half the enclosure space. The downside is the drop in efficiency and twice the required amplifier power.


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## NJPCRX (Jul 25, 2012)

*Re: isoberic stroker set-up*

so what happens when you clamshell another speaker out of phase on a setup that is already housed in a proper size enclosure? I know that porting doesn't change cause the physical box doesn't change.


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## TrickyRicky (Apr 5, 2009)

*Re: isoberic stroker set-up*

Only one way to find out.....


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## splaudiohz (Apr 1, 2011)

*Re: isoberic stroker set-up*



TrickyRicky said:


> Only one way to find out.....


Best answer yet.


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## squeak9798 (Apr 20, 2005)

*Re: isoberic stroker set-up*



NJPCRX said:


> so what happens when you clamshell another speaker out of phase on a setup that is already housed in a proper size enclosure? I know that porting doesn't change cause the physical box doesn't change.


The physical characteristics of the enclosure doesn't change. But how the driver responds to that enclosure will change. Switching to isobaric with a driver that's already in an appropriately sized enclosure for a single driver is exactly the same as putting a single driver in an enclosure twice as large with the same tuning frequency. 

So if you want so see the change in response, model a single driver in an enclosure twice as large with the same tuning frequency.


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## SUX 2BU (Oct 27, 2008)

*Re: isoberic stroker set-up*

I tried this once. Had a single 10 in a ported box and decided to just add another of the same make/model to it and see what happened. I had an old Alpine amp running bridged to the sub so I made it a series arrangement to make it easy on the amp so I had an 8 ohm bridged load. Output dropped MASSIVELY. I get that because I now have 1/2 the power out of the amp running 4 ohm vs. 8 ohm and I also dropped output due to the isobaric configuration. I wasn't impressed lol


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## NJPCRX (Jul 25, 2012)

*Re: isoberic stroker set-up*

Ya, but I have the capability to double the power SUX. I'm giving one sub rated, and I can give the other rated too, if I add it. If I do that squeek, the curve is way more peaky, but overall it drops the tuning 2db, and raises the output significantly around 35HZ. Is this accurate? Because if I keep the original box, but add another woofer in WinIsd and select isoberic, the graph is unchanged from the original one woofer set-up.


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## moparman1 (Jan 16, 2014)

*Re: isoberic stroker set-up*

If I'm understanding what you're suggesting, I can't see how this could possibly be an isobaric clamshell. Just because two drivers are facing one another in close proximity, doesn't make them isobaric. They need to have a sealed chamber of air between the drivers. Thus, coupling the two.


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## NJPCRX (Jul 25, 2012)

*Re: isoberic stroker set-up*

They would be coupled with one out of phase. My question is the box size already being to spec. I designed another box in WinIsd which was just everything doubled and 2 speakers. So I just opened that project, and changed 2 woofers to 1, and deleted half of the port like squeak said. It looked really peaky around 35Hz. I could throw it together and see what happens I guess. Might be a one note wonder. I'll try to paste the graph in here later today if I can figure out how


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## NJPCRX (Jul 25, 2012)

nobody has anything to say?


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## minbari (Mar 3, 2011)

some things to consider when going isobaric.

with the same wattage, you will lose 6db of output over the same design with a single woofer. looks like you are going to double power, so you will only lose 3 db. no way around it. isobaric is a loser in the output dept.

you do get better distortion and an enclosure with half the volume. but that is the only advantage.


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## theoldguy (Nov 17, 2009)

I have no input on your question, but I do want to ask why you are in Clovis. I was there for 24 hours and that was more than enough for me. I commend you for have a useful hobby though like car audio instead of running drugs for the cartel or whatever other shenanigans takes place in Clovis.


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