The panels are made using 1/8" ply with corner braces to hold them together and hold the fiberglass panels in place. I used thin ply to keep costs and weight down as these are strictly testing panels. It worked quite well and I will probably keep these two the way they are.
Charts:
The purple trace in all plots is the untreated response and is put in for comparison.
This one is the rear wall location you see in the first photo. I was quite surprised at how low the panel effected things. You can see some smoothing in the 22-33Hz. range.
The other big surprise was the elimination of the 40Hz hole. You can also see a reduction at 80 and 120Hz suggesting that this is a room length mode.
The big dissapointment: it got worse at 52 Hz.
Front Wall placement (2nd pic). Slight improvement at 52Hz and the 75Hz null narrows quite a bit.
Corner Placement. Interestingly here the 75Hz null is reduced a little, but not narrowed.
I was curious to know how the dining area affected the room overall. A lot of the effects are the same as other placements, but this one shows the best improvement in the 75Hz null. I wonder if this is a room mode somehow related to the width at this part of the room?
I still want to put the panels over the spl meter to see how that effects things.