# Room extension subwoofer enclosure?



## ashman5 (Sep 24, 2007)

Hey guys,

I do a lot of lurking, but this is my first question. Should be an easy one for you guys. Hope this hasn't been covered before.

I've included a diagram, hopefully, to make this easier to understand.

I want to get my subwoofer out of my main home theater area. I want to build a small (3x3x3) insulated box behind the screen wall, in an attic area, big enough to hold a subwoofer enclosure. NOTE: this box will NOT be the subwoofer enclosure, just a box to protect the actual subwoofer from attic temps. It's, basically, just a small addition to the main room space with the sheet rock removed and a speaker grill covering the removed sheet rock.

My question is how do I calculate the size the sheetrock cutout needs to be? I don't want to restrict airflow, but I only have ~16" between the bottom of the screen and floor.


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## Mike P. (Apr 6, 2007)

The sub you choose will determine the size the sheetrock cutout needs to be. Do you have a sub or will you be building one?


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## ashman5 (Sep 24, 2007)

Sorry, I currently have an Audiosource SW Fifteen, but will probably build something else one day. 

I believe I can get about 12" vertically and 24"-30" horizontally. Would that be enough to accomodate my current sub and future upgrades?


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## bpape (Sep 14, 2006)

Ideally, you really don't want to do what you're suggesting. Any time you put a sub or any other speaker back in a recessed 'tunnel' like that, you're going to completely change the frequecy response and cause all kinds of resonances that you really don't want.

Bryan


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## Mike P. (Apr 6, 2007)

It should accommodate the Audiosource if you lay it on its side. As for future upgrades, that will depend if you have access to the "room" from the back side, as a larger sub won't fit through the front access. Usually ugrading means something larger, a point to consider. A DIY sub can be built to fire through the 12" x 30" opening.


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## Mike P. (Apr 6, 2007)

bpape said:


> Ideally, you really don't want to do what you're suggesting. Any time you put a sub or any other speaker back in a recessed 'tunnel' like that, you're going to completely change the frequecy response and cause all kinds of resonances that you really don't want.
> 
> Bryan


As long as the sub is flush with the opening it should work, I think?


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## bpape (Sep 14, 2006)

In theory, yes - but you're also then (assuming a front firing sub) extending the baffle to be the entire wall. I don't think that's what he's talking about though. I think he's discussing building a micro-room in the attic to put it in and then just have a smaller opening into the theater space. Any space that the sub sits in that is not filled by the sub itself is going to resonate.


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## ashman5 (Sep 24, 2007)

bpape said:


> Ideally, you really don't want to do what you're suggesting. Any time you put a sub or any other speaker back in a recessed 'tunnel' like that, you're going to completely change the frequecy response and cause all kinds of resonances that you really don't want.
> 
> Bryan


hadn't thought of it that way. this might not be a good idea after all.


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## tcarcio (Jun 27, 2007)

Wouldn't his situation be good for an IB??


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## bpape (Sep 14, 2006)

Sure - if he wanted to build a new sub and buy a new amp and xover. That would certainly provide a huge jump up in sub capability. I'm assuming that the OP wants to keep his existing sub.

If you do want to keep what you have and have it hidden, you'd at a minimum, want to have the opening the full size of the 'room' behind and just covered with cloth. You'd also want to cover the interior of that recessed area with absorption of at least a 3-4" thickness.

Bryan


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