The Wall

It was the most ambitious do-it-yourself carpentry work I've done in five years, ever since I covered the windows in my home theater studio to shut out the light and minimize extraneous outside sounds. The latest project involved building a false wall directly in front of an existing wall, not only to conveniently hang an expected ongoing parade of flat panel displays coming in for review, but also to facilitate a planned series of on-wall speaker reviews. There's no question that on-wall speakers are a significant trend, and one that we can't continue to ignore here at Ultimate AV. As for in-walls, well, that's a project for the future.

Since the main home theater space remains dedicated to full size systems with video projectors, the new on-wall setup was to go in a smaller den. This room measures 13' x 17' x 8.5'. Centered on one of the 13' walls and jutting out into the den by about 2' is the back of a fireplace located in the next room. The brick rear of the fireplace has long since been covered with studs and sheetrock. It was on this 63"-wide space that I chose to build "The Wall." At its top is a solid 4x6 beam, to which the false wall could be firmly attached.

Briefly, the design involved using long lag screws to fasten each of the four 8' 2x4 studs to that overhead beam. To provide a more solid grip, the studs were mounted with their 4" dimension (actually closer to 3½" if you know your lumber) flush with the wall. The studs were then covered for most of their height by ¾" plywood. While plywood is less typical than the sheetrock most people will have for a mounting surface, it will hold up better as multiple holes are drilled for a steady progression of speakers. It would also further strengthen the whole structure.

To mount the display, which would initially be a Pioneer 50" plasma (review in progress), I bought a simple but sturdy Sanus Systems VMPL2s Visionmount. The center two studs were spaced so that the main mounting bracket of the Visionmount could be screwed through the plywood and into the studs, with everything calculated to center the plasma on the 63" wide structure.

Those center studs, the ones to which the plasma mount would be fastened, had to be strong. Even stronger than usual, in fact, since I was screwing the mount into their shorter dimension. In my opinion, ordinary fir studs simply wouldn't hack it.

The obvious answer was oak, probably the strongest hardwood generally available. You won't be able to find 2x4 8' oak studs in most lumberyards, but I was lucky; I found a local yard that had 2x6 oak studs, but not 2x4s. So I had them rip one down the center, giving me two incredibly strong 2x3s. They used to make ships from this stuff! But the price for this one piece of oak—$45—would rattle even Old Ironsides. Still, the peace of mind the strength of oak provides (I do live in earthquake country) is well worth it.

It took over a day and five trips to local lumberyards and home improvement stores, but the wall went up without any major glitches. I covered the whole affair with thin, decorative felt to hide the raw lumber look until I could come up with a better solution. I also plan to build removable "wings" to mount on the left and right sides to more closely simulate the acoustical loading of a full-width wall, which typically will extend out to the sides of wall-mounted speakers.

This is where I'm supposed show you the many photos I didn't take during what was a rather hurried construction project. Instead, I've included a single shot, showing the wall with the top few feet as yet uncovered so you can see the new support studs. The PSB speakers shown are one of three sets scheduled for review in the first batch. The others are from BG and Sonus Faber.

Now where did I put that Pink Floyd album?

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Jeffrey Bean's picture

Tom, interesting setup. Given the importance of the room in evaluating speakers, have you found the partial wall panel to change the characteristics of the room significantly? Specifically I was curious if the space behind the wall (assuming it was left open) has any significant impact on room response? Either cancelling standing waves noticeably, or potentially letting the plywood act a transducer from the speaker energy when played at movie level volume? Cheers,

Bruce in HR's picture

How in the world did you get this one past the significant other? I realize that this is your livelihood, but there must still be some threshhold resistance in reviewerland. My wife would have smacked me over the head with one of the oak 2x6s for even suggesting such an idea.

Colin Robertson's picture

Great idea Tom, just one thing... Wouldn't the fact that the wall isn't a typical wall affect the sound of the speakers, making them sound different than intended? I mean, in the photo, the speakers are at the edge of the wall, eliminating that large piece of sound reflecting wall that everyone else would have, and that speaker designers have to deal with.

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