Depth of Diaphragmatic Absorber (D)-Acoustics Forum-Acoustic Fields Forum

I bought the plans to build the Diaphragmatic Absorbers. The sound room is 22′ x 19′ and therefore there is no surprise that I have a node(s) at 99 hz and 206 hz. I am fine below that.

Is there a particular depth(s) to the DA that would help in this range. I do realize the DAs can go lower if built correctly but these are the nodes I am having to deal with.