There’s no shortage of DIY bass traps plans online that are variations of a fabric wrapped 4” frame around some form of insulation. My guess is these will be effective above 125 Hz
I have a 11’ x 14’ space that needs help below 400 Hz but in particular a suck out centered about 70 Hz.
Is anyone familiar with lower reaching designs or a calculator to help tune traps? I understand thicker traps will attenuate lower frequencies but would like to know how to tune the depth and air gap.
Thank you.