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Discussion Starter · #1 ·
I am mounting ceiling speakers in a ceiling that is open to an attic. The manufacturer told me that they would sound much better in a 1 cuft enclosure. They recommend 3/4 mdf, sealed, braced, and stuffed. I could probably figure out a way to keep that heavy mdf enclosure from breaking through the ceiling, but I'd rather not.

So, if I were to make a sealed, stuffed, 1 cuft enclosure, and my choices were a styrofoam cooler, a plastic garden pot, or a cardboard form for concrete pilings, which would be best? (I'd be using thin plywood on top of the drywall in all cases.) Thanks!
 

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You'll want to link the actual speaker so we can provide more accurate info- I wouldn't try any of your alternatives- you'll be better off just not having a backer box. If the speaker would fit and you have 16" space between rafters I'd look for knockdown enclosure that fits with simple shimming.

http://www.parts-express.com/denovo...056-cu-ft-bookshelf-speaker-cabinet--300-7064

http://www.parts-express.com/denovo...067-cu-ft-subwoofer-speaker-cabinet--300-7068

http://www.securitystoreusa.com/mobile/Product.aspx?id=697369

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Um, what is keeping you from screwing an enclosure to the studs / ceiling joist? Make an made box that fits between the ceiling joist and screw it to the joist or to a 2x4 that spans across of the top of two joist. Easily done and no need for special enclosures.
 

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Discussion Starter · #4 ·
I appreciate the input.

Thanks for the link to the cabinets. Still very heavy and a little pricey for 1 ft3 enclosure. But much less than the manufacturer.

I'm still considering a proper mdf box, and making it such that its weight is supported by the beams rather than the drywall.

But I'd still like to get comments about those other materials. If no enclosure is a 5, and a proper mdf enclosure is a 10 in sound quality, how would those other sealed and stuffed enclosures of the proper size work?

As far as linking the actual speakers, the manufacturers gave me specific volumes. All 3 said that it could be in any configuration, as long as the enclosure or stuffing didn't interfere with the driver. For a 0.6 to 1 ft3 enclosure, do dimensions matter?
 

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No- dimensions do not matter- and none of your alternatives sound like they would be dense enough, strong enough, or easy to seal airtight- making them useless. If you have access to put a box on the backside of the speaker you have access to the rafters- again- do it properly with an MDF enclosure or just leave it open.

Are the speakers for background/whole house audio or for HT?
 

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Discussion Starter · #8 ·
Thanks, again, everyone.

Would I want to use the ceiling drywall, itself, as the 'front' of the speaker, or would I want to use a piece of mdf laying right on top of the drywall? (And have a cut-out hole for the speaker in both the drywall and mdf.)

I like the idea of supporting the weight by using the top of the existing joists. But I'm having a tough time trying to figure out how to get the depth exactly right. If it's not deep enough, I may have a small gap between the drywall and front. If I make it just a hair too deep, it may bulge the drywall when I attach it. So, I'm trying to figure out how I would get the 'top' and 'bottom' dimensions exactly right.
 

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What is wrong using the cardboard sonotube with plywood at each end? use some metal duct hanger strips or threaded rods to your rafters to support the weight?


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No, the drywall itself can't be the front of the speaker, it will only be there for looks. Imagine the drywall as a useless piece of glass that will break if you hang a mosquito on it. You need a proper MDF sheet for the speaker itself, then a hole in the drywall that's the same dimensions as the speaker. But even that will be messy, making perfectly round holes in drywall? I don't touch drywall with a ten yard stick because everything involves mudding and painting to get a nice finish.
Just keep it simple, draw up an enclosure using the limited dimensions at your disposal, lets say you have a certain depth and width maximum. Then go with that as the two dimensions, and then calculate how large the third dimension needs to be to get the required volume. How it will look on the outside has nothing to do with how its actually built, add whatever beauty-panels you wish, but behind that the speaker will be screwed to an MDF sheet and the enclosure itself screwed to the studs or joists.
 

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If you're going to do it, you should do it with a product designed for the purpose:
http://www.monoprice.com/Category?c_id=108&cp_id=10837
Cutting a rectangle in sheetrock isn't that hard. The box is then covered by the grill, so it doesn't have to be perfect.
I have two in-walls. Running the wires was the hard part.
Use the speakers you have for mid-bass modules. ;)
 

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...I like the idea of supporting the weight by using the top of the existing joists. But I'm having a tough time trying to figure out how to get the depth exactly right....
Use a 2 x 8 (or whatever your joist size is) to perfectly space the cross braces that go on top of the joists from the back of the drywall. Here is a rough sketch of the 2 x 8 spacers with the hanger strips attached on top.

Sport venue


The bottom square is MDF (and becomes the bottom of your box, you would glue or caulk this to the drywall and screw through the drywall into this piece). The large MDF ring in the drawing is for attaching sonotube, if you go that route.

Edit: Squarish enclosure (with back off). Bottom MDF piece can be sized to fit box. Box just has to fit between joists (typically a 14-1/2" space). Personally, I would only use a scrap of 2 x 8 as a jig, just to locate and attach the cross bars to the box.

Technology Architecture Diagram Box Roof
 

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For my inceiling Infiniti ERS 310's in my garage, I used 1/2" mdf connected to the 2x4 joists and covering the top as well.... Braced them internally, and used polyfill hot glued to the 2x4s and mdf!

Sounds pretty damn good for a pair of 2 way in ceilings speakers! Keeps the sounds contained much nicer than without for sure...:)
 

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If you're going to do it, you should do it with a product designed for the purpose:
http://www.monoprice.com/Category?c_id=108&cp_id=10837
Cutting a rectangle in sheetrock isn't that hard. The box is then covered by the grill, so it doesn't have to be perfect.
I have two in-walls. Running the wires was the hard part.
Use the speakers you have for mid-bass modules. ;)
The OP stated that he is looking for 1.0 cu. ft. volume.
I am mounting ceiling speakers in a ceiling that is open to an attic...they would sound much better in a 1 cuft enclosure....So, if I were to make a sealed, stuffed, 1 cuft enclosure...which would be best?...
 

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Discussion Starter · #16 ·
Lots of good comments and ideas. Thanks!

All of this made me think that a good option for me might be to get a couple of subwoofer boxes for cars. I can get them for about $30 each. My cutout requirement is a bit bigger than the standard for a 10" sub, so I'll have to make the hole bigger. I can find some that are pretty close to 1 ft3. (I don't know what the effect of being 0.2 ft3 too small would be.)

I'd be able to go up into the attic, remove an area of blown in insulation, and place the subwoofer box using a wire hanger for a small 'locater' hole. Then cut the hole in the ceiling drywall from below, tracing the subwoofer box hole. (Hopefully, the ceiling drywall would be able to hold the weight of the box while I'm doing this.) Luckily, my ceiling speakers are big, and take a 10" cutout. So, I'd be able to use a small drill to fasten the box to 1 of the ceiling joists, from the inside of the box. I'd probably want to figure out how to attach the box to the adjacent joist somehow.

I'm thinking the carpet on the front baffle may help dampen vibrations in the drywall?

One issue I see is that the weight of the unsupported box is probably going to flex the drywall during installation, and then stay that way permanently. I'd like to figure out how to support the weight EXACTLY at the level of the top surface of the drywall during installation. Heck, I may just want to leave it that way. Any ideas on how to support that box at a precise depth, using the existing joists?
 

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