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Discussion Starter #1 (Edited)
I want my system to be as stealthy as possible and not take up space, so I am going with some custom enclosures that fit in the rear corners of my A4's trunk.

Im using 2x JL 10W7 subs, and a JL 750 HD amp. The enclosure on the right has 0.65 cubic feet, and is stuffed with 1 lb of poly fill. I know JL recommends 1.5 cubic feet for the 10W7, and Im no audiophile, but it sounds excellent to me.

I havent installed the other yet. The enclosure on the left will have 1.0 cubic feet. What I want to know is, should I stuff this box with any poly, and if so, how much?

Also, I know its not ideal to have two subs facing each other, but this is the only way I can do it. Will I have a problem with cancellation?

Here are the links to what im using.
http://www.amazon.com/gp/product/B0002ZPLDY
http://www.loslabs.com/product_detail.php?
http://www.audiointegrations.net/catalog/item/8086876/8722954.htm
 

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Honestly, that is not a good idea. Those enclosures are too small to get good extension out of a 10W7 to begin with, but more to the point, it will be tough to eq them to match response.
 

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Discussion Starter #3
If I am already getting sound that im happy with from the smaller enclosure, I dont think ill have a problem with the other one. This is the setup I am going to use, Im just looking for advice how how to optimize it.
 

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Discussion Starter #4
here are some of my thoughts.

polyfill can simulate up to a 40% larger volume in boxes under 2cf.
1.5 lb per cf is the recommended max fill to use.
1.5 x 0.65=.975 (almost exactly 1, so I think im safe there.
.65cf x 140%= 0.91, a simulated volume of almost 1cf

If I don't stuff the second, larger box, that means they will both have about the same effective volume right? I know I'll loose some of the low end, but I just want to avoid distortion, coloring and crossover

I know this is not recommended, but like I said, I have limitations. I'm just trying to make the most of it.

When I have both subs hooked up to the 750, I will not be pushing them too hard, so it seems to me it will work.
 

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you've got a problem you can't account for...

The different sized boxes could create some really odd electrical interactions being that they will both be connected to the same amp...

ones impedance curve won't match the others (not that they "match" but in identical enclosures, they are a lot closer)

This could cause some really odd happenings, then again I could be completely wrong... I guess it's up to you to find out...
 

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I understand that you are trying to make the best of it, but those subs could each handle a 750/1 on their own. Running a pair of them on that amp, let alone in different boxes, seems like a bit of a waste.

Even if stuffing does make up for some of the missing enclosure volume acoustically, the impedance will still be different. Maybe you'll be OK, maybe not. As long as you have a warranty on all of it, go ahead a try it.

Perhaps you could install some blocks of wood into the larger enclosure in order to equalize the displacement.
 

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You could link the two enclosures with a pipe. This would add additional volume to the total of the two enclosures, and would effectively put them both in the same box, which should, in theory, smooth out the difference between them.

I hope I'm right in my thinking :D
 

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Unless the tube has a VERY large ID this will not make them act as if they are in the same box. The tube will add a reactive component to the system. Without modeling what that reactive component is you could not accurately predict what the result would be (could be better or could be worse).

Since you are so space contrained I wonder if AP wouldn't be a better approach. The only rub is you would need a way to port the back side of the mat to the outside. What is the Qts of those 10"s (it needs to be below .7 for AP)?
 
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