is inwall speaker preparation needed?? (1 Viewer)

[Bobby J.]

I need your guys advice.I recently bought Polk RC85i and RC65i inwall speakers for my home theater.My question is do i need to do anything between the wall studs where the speakers will be to get the best sound? I don't have drywall on the walls yet so now would be the time to do anything that is needed. Please give me some advice.

 

[Wayne A. Pflughaupt]

One of the biggest problems with in-wall speakers is that the “cabinet” is really flimsy compared to regular speakers, which can cause coloration. You have a primo advantage to be able to address this situation somewhat.

To that end I would recommend using 5/8” sheetrock, which is more rigid than 1/2.” I would also add cross braces to further stiffen up the area around the speaker. Run a couple of horizontal 1”x4”s, 2”x2”s, etc., above and below where the speaker location will be, leaving a few inches clearance on both sides. I would also run a couple more braces vertically between the two horizontal ones, again leaving a few inches clearance on both sides.

In other words, you’ve build a square frame all around the speaker, which will stiffen up the “baffle board” considerably. Naturally, all this has to be flush with the front edge of the studs. When you put up the sheetrock be sure and shoot some screws through your frame, to secure it to the sheetrock.

The important thing with the braces is that you don’t want to use 2”x4”s. If you do you will essentially create a tiny enclosure for the speakers, which will severely limit bass response. That’s not what you want, because in-walls are essentially an infinite baffle design that utilizes the in-call cavity for their bass response. Thus using braces that are not as deep as the studs will keep the wall cavity fully open to the speaker. Hope that makes sense.

Regards,
Wayne A. Pflughaupt

 

[Bobby J.]

should i remove the insulation from the walls?Also polk recommends 1 cu. ft. of air space for these speakers. Should i box in with mdf board inside the walls?IF I FIGUARED IT CORRECTLY A 4 FOOT BY 1 foot box 3.5 inch deep is 1.2 cu. ft. does this sound like a good idea?

 

[Wayne A. Pflughaupt]

There’s no need to remove the insulation (unless Polk says otherwise); many speakers have internal insulation.

You can still stiffen up the front baffle area as I recommended above, and use cross-braced 2”x4”s to make the maximum size you want. There’s no reason to use with MDF for that. Just make sure and seal everything up nice and air-tight with some caulk.

Regards,
Wayne A. Pflughaupt