Ian_J

What acoustic problems are caused by a hard soffit?

I’m considering building a soffit around my HT room to cover pipes. Does anyone know how this will impact the acoustics of the room? I’ve heard that an acoustic soffit will improve the sound of a room but a hard soffit can be a nightmare. If this is true, any suggestions on how to build one myself? ASC offers an acoustic soffit product at the bargain price of $90.00 per square foot. The cost of installing it in my room would be $2,160.00. I’d rather spend the money somewhere else.

Thanks,
Ian

Dave Milne

Ian,
I took a look at ASC's website and their "acoustic soffits". It appears that they have combined the properties of soffits, corner bass traps, and high-frequency absorption in one product. Since Acoustic Sciences is a pretty savvy bunch, I have no doubt that their acoustic soffits are effective.

But, as you suspected, you can achieve similar results at lower cost with other approaches. Ordinary hard soffits - the framing/plywood/sheetrock type as I have in my theater front view or my theater rear view generally improve the room acoustics by "breaking up" the wall-ceiling corners and reducing slap echo.

For additional bass control, you can supplement the hard soffits with tube traps, bass traps or LENRDs from Auralex, diaphragmatic absorbers, etc.

For upper frequency control, you can supplement with absorbers of various types: DIY cloth-covered panels, carpet, overstuffed furniture, "blade" or "pyramid" panels, Sonex tiles, etc. The trick is getting the right balance of reflection, diffusion, and absorption. I used Auralex 2" studiofoam wedge panels in plum along the front wall and part way down the side walls, Markerfoam window plugs, and hollow columns with fiberglass stuffing. The bookcases provide natural diffusion. Overall my room is a bit dry for music listening, but just right for HT.

Auralex has some good tutorial material to download from their website. Generally as a minimum, you want absorbers at the first reflection points from your main speakers.

Good luck

Ian_J

Thanks for the wealth of information Dave. It’s almost too easy to get a good answer on this forum. Very impressive HT room, too! You mentioned that you have “hollow columns with fiberglass stuffing”. Like the soffit, I assume they break up the slap echo?
Do they negatively affect the room in some way? I would assume that too much sound diffusion and dampening would make a room sound “stale”or “flat”. The whole process seems to be a balancing act as well as a taste preference. Seems like I should go read up on the subject before firing off a million questions.

Well, off to Border’s I guess.

Thanks again,
Ian