Bass traps? (to solve a suck out)

61 Hz; that's specific.

Before getting into room accoustics, experiment with the positioning and integration between the sub and the speakers. Sounds like a phase issue to me.

Of course, it could be just the microphone or SPL meter you used. They are notoriously inaccurate at lower frequencies. Even the testing labs don't certify below 100Hz.

After playing around with positioning and settings and you still have the same issues, come back and discuss bass traps. A null at that frequency would indicate a fairly large room volume and, probably, an unusual ceiling.

Oh, I could have sworn I saw something about a subwoofer in the origional post.

61 Hz has a wavelength about 18.5 ft. 1/4 is about 55 inches. Want to do some measuring of your room and where the speakers are sitting? If the bass drivers are open baffle, the reflections can be either phase.

Onhwy61

If you're treating reflections properly, you're treating both nulls and peaks.

For treating 61 Hz, I would consider 1/4 to 1/2" membranes, 3 to 4' wide and 6 to 8' tall. That would be with a practical 4 to 6" depth and 703/705 dampening. I haven't done the math yet but that's based on my work with 4' by 2' membrane panels which were efficient around 100 Hz. Not likely to buy anything that size off the shelf because it's just too big to ship. I wouldn't even consider "soft" traps for this frequency.

I wonder if there's a market for membrane trap kits? Just the unassembled frames (Ikea style). The rest can be obtained from building stores.