Hi Scott and welcome to this massive thread.

The soffits that I put in, and most soffits for that matter, don't do much if anything for the acoustics inside the room. There are too many flat/hard surfaces.

People use them to run wiring and lighting, as you mentioned, as well as a place to hide long HVAC runs of insulated flexible duct so that it has plenty of space to obsorb the sound waves traveling through it.

Now, there ARE people that have turned their soffits into large acoustical pannels/bass traps. They basically replace the bottom and sometimes the sides (with just enough structural support) with acoustical dampening material and then cover the soffit with acoustical fabric. That is a lot more work, but I am sure that there are great acoustical benefits to it since you are adding absorption to the entire "top of the walls" corners around the whole room.

You can still run gyour HVAC ducts, cabling, lighting, etc through that space as well.

For me, personally, it was a matter of time and money. It would have cost significantly more and taken a lot more time to do. I am not building an "all out, no holds barred" theater, but something that is more modest and still has a number of improvements over a basic theater space.

My 2nd sub goes in tonight, and I am already getting my wife convinced that it is time to build acoustical panels for the walls. For about $150 in materials and a little bit of build time, I should get a great improvement in sound. I really should have built those sooner since the "bang for your buck" value is so high.

This is by no means that "best theater build ever" and I've learned a number of things along the way. I am super happy with how the theater looks (in person when the camera colors aren't wonky) and sounds compared to any previous version of my theater (2 other houses, 3 other theaters).

Thanks for stopping by and if you have other questions, just fire away.

EDIT: Here is a link with someone asking about how to add acoustical material to a soffit. A user there, BIGmouthinDC links to an AWESOME theater (that by the way uses Axiom Speakers) that put acoustical material in the soffits and how it was done. He makes it sound so simple, but then again 'BIG' helps with installs as a living.

How to mount rigid fiberglass to soffit?

Last edited by nickbuol; 07/11/13 01:31 PM. Reason: Added link
Farewell - June 4, 2020