Ceiling speaker enclosures

[kmak]

Hi,
I have a pair of B&W CCM663 that are sitting in a box, doing absolutely nothing, since we moved here 2 years ago.



Fortunately, during construction, I had the electricians run speaker wire to a decent location for the rear/side surrounds in a 5.1 system. I was able to use Paradigm outdoor speakers, that were on the deck at the old house. They've been more than adequate, but I might as well match brands with my HT.



Left Surround:



Right Surround:



The bottom line is that I would like the enclosures to blend into the drywall finishes, as much as possible. I'm thinking of mdf screwed, glued, and lined with acoustic egg crate foam. Then I would adhere Sheetrock with rounded corners. Would a triangular "box" at the same angle as the Paradigms above work, and what should the internal volume be, within reason? Has anyone else completed a similar project?

Thanks in advance,
Ken

[Bear]

There are lots of similar in-wall projects, but given that this is a DIY forum, I'm not quite sure how to answer. The B&W speaker is going to come with its own crossover and a set of assumptions around implementation. That makes answering your volume question little more than a SWAG (design parameters could range from 2x4 framed walls, 16" OC, to full Infinite Baffle). No matter what you do, though, the column width will look a lot more like a wide baffle speaker than a true in-wall (unlike the one on the wall with the fireplace). Substituting ceiling bounce for floor bounce, and baffle step should be only ~2dB or less. However, the two placement locations are different enough acoustically to make it hard to give a general answer that works for both.

Finally, there are better acoustic fillers than egg crate foam -- including basic fiberglass or denim insulation. From a fire risk standpoint, you probably don't want to go with denim on the wall close to fireplace. You certainly don't want to go with a plastic derivative like egg crate foam. Fiberglass will be much less flammable than denim, and denim will be much, much, much less flammable than egg crate.

TL,DR: it should work, but you'll need to make (and live with) some assumptions.

[kmak]

Thanks Bear, since this is sort of a custom installation as well, I posted a link to this in Spaced Out.
Ken

[Steve Manning]

You could always contact B&W and get a recommended volume.