Friday Mailbag – Studio Tube Trap Problem

Hi Mike,

I’m helping a friend with his studio. He’s got a live room which is roughly 25″x8″x9″. It’s pretty much a square concrete tube with acoustic foam in some spaces but not enough to cover all. Any suggestions on how to treat the tube resonance issues? Would rock wool traps help? Any ideas or tips would be greatly appreciated.

Thanks
Cain

Hi Cain,

The 25′ dimension is good but the 8′ or 9′ width or height is not. The axial mode issues between the short side walls will require at least a 12″ space loss on each wall in order to provide the necessary real estate to minimize them or lower their nuisance value at the mixing or listening position, leaving a 6′ horizontal wall dimension. This is not exceptable in any acoustic sense. There will be many axial modal resonances and they will all possess lots of power at their respective room mode positions with in the room. They will overpower your middle frequencies and you will always be working around them in the mix.

Try to find a room that has at least a 12′ width. We really need a minimum of 12′ to fully accept a 100 Hz. wavelength. Hopefully, you can keep the 25″ length. Rock wool traps will not provide the rates and levels of absorption needed for your room size. They will work within their design parameters. There design parameters will not go low enough to handle your issues.

Regards,
Mike