Creating a system you love shouldn't be difficult. The Acoustic Frontiers blog is here to help.
Most people don't go to the effort of building a proper THX specification baffle wall to house their speakers. In most cases people build a light weight frame just to hold the speakers and screen. While this is 'ok' it does not offer the benefits of a true baffle wall. [caption id=" align="aligncenter" width="640"] The finished baffle wall with the cutouts for the Procella P610 LCRs and the P10 subwoofers (and a bunch of tools...).[/caption]
There are a couple of major acoustical benefits to the baffle wall...the first is that there is no speaker boundary interference from the front wall behind the speakers, since the speakers are mounted flush with the surface. The second is that the baffle wall essentially removes the 'baffle step' which happens when the speaker radiation transitions from half space to full space as the frequencies exceed those which can be controlled by the baffle. If your speakers are designed for flush mounting in a baffle wall, as Procella speakers are, then you gain 6dB of headroom in terms of the ability of the speaker (or sub) to reproduce say reference level (105dB peaks). The third is a bit more debatable depending on the importance you attribute to diffraction (some say it is important, others say hogwash!)...there is little to no diffraction with the speaker mounted flush in the wall. From a sound quality perspective these things mean that the sound tracks cleanly from left to right with no jumps, we have more headroom at low frequencies and we have better bass free from boundary interference suckouts. A proper baffle wall is at least 1.5" thick and comprised of multiple layers of material, primarily to stop the baffle wall from becoming a giant speaker. This might happen if thin material were used as the speakers sit in the wall and hence transfer energy to it. In this particular wall we also finished the edges of the speaker openings for a neat look since the acoustically transparent Seymour Screen Excellence screen will be retracted when listening to music and hence the openings will be visible. Finally the black material on the floor is a 1/2" thick rubber underlayment which helps isolate the room from the rest of the building. The floor is definitely a compromise in this room because we had to balance sound isolation with added floor height. Ideally we'd have added at least a new 3/4" layer of OSB over the floor planks but this would have made the floor of the demo room an inch higher than the rest of the building. It's a good example of having to find workable compromises...sometimes performance doesn't always come first... Stay tuned for part III which will provide more details about the soundproof door and room testing!
Nyal Mellor, Founder, Acoustic Frontiers