Severe Echo in small room under garage – spray foam
Hi all, I have finished space in a basement about 18 x 9 x 7. I hoped to make it a small little movie room with an 85 inch TV.
We poured concrete over steel so the ceiling is metal and a large part of what is causing an incredible echo.
Unfortunately I was told spray foaming (closed cell) the walls and ceiling would help with the echo but I now know that is false.
I’m wondering if it makes sense to pull out the foam and replace with Roxul or just try to come up with a solution once I’ve put Sheetrock in.
Or, the sad option, which is to just use it as storage 🙁
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It's possible that your sound system is overloading the space. For example, the speakers I am currently building require at least 2,500 cubic feet of volume to operate properly. So you may need speakers that are a better match. Or you may need some acoustical treatment to address the artifacts that are creating the echo. A number of companies make panels for this purpose. But before you spend any money, I would suggest going to the avsform or another audio and video site and asking for input on how best to improve your room.
There's plenty of ways to mitigate the problem; professional recording studios are usually in buildings of steel and concrete construction. It might be as simple as using acoustical panels on the ceiling, if that's where the bulk of the problem is. Like Steve said, a site specialising in hifi audio or home theatre is probably a better source for information on this topic.
I'd measure RT60 with "REW - Room EQ Wizard Room Acoustics Software" before starting mitigation. Then you know if you need bass traps or which panels.
Have you tried adding an area rug and furniture to the space? That can make a surprising difference. The worst thing you can have are two parallel surfaces that are highly reflective, like your steel ceiling and concrete floor. Mineral wool panels wrapped in fabric and attached to the ceiling (leave a space between the ceiling if possible) will make a dramatic difference, and even more so if you add a few panels like this to the walls.
One way to sneak in some acoustic treatment is to get a large canvas wrapped painting or canvas printed photo on a wooden frame. Between the frame pieces you can install hidden mineral wool pieces.
Typically, placing acoustic panels covering 50% of the ceiling, and two adjacent walls should take care of most of the problem. The panels should be evenly distributed on the surfaces for maximum effect. you can purchase 2inch foam or better yet Roxul wrapped in fabric. Generally speaking, if you can blow through the fabric, it is appropriate for sound treatment. Hope this helps.