Q. I read on the Axiom forums that the M80′s can be placed as close as 2 inches from the back wall. I’m hoping the same is true for your new VP180 centre speaker (this is important to me as the room I have has an angling bulkhead, which means I would need to mount the projector screen on the ceiling fairly close to the wall). Can you please comment on how close the 17-inch-deep centre channel should be placed from the wall? —B.P
A. Yes, 2 inches of “breathing room” for the port applies to the VP-180 center channel as well as to the M80s. It isn’t so much the specific port distance (a couple of inches is certainly ample space for the port energy to be expelled into the room) as it is the location of a speaker to “adjacent surfaces”, which means the wall behind, the floor, and the side walls. And this applies to any speaker, sealed or ported, that is capable of producing significant bass output. The closer you place a speaker to the wall(s) and/or floor, the greater the bass output you’ll hear. That’s because the adjacent surfaces have an amplifying effect on bass frequencies.
At its most extreme, a corner location where you have three adjacent surfaces (two intersecting walls and the floor), will have the greatest effect, and the increase in deep bass will be quite pronounced. However, the bass emphasis may be uneven, with some tones seeming to “boom”—jump out at you, while others may be inaudible. Generally speaking, I advise customers to avoid placing any speaker in a corner except for subwoofers, because of the potential to make the speaker sound boomy (subwoofers will sometimes work well in a corner placement.)
Conversely, the farther you move a speaker away from walls at the side or rear, the less emphasis there will be of lower bass. You shouldn’t have any problem with the VP-180 center close to the wall behind. Keep it away from corners and as close to the bottom of your screen as possible.