Originally Posted by sdurani
Yes, on the left & right walls.
Think of your width modes as a ball bouncing between your left & right walls. If you place things on the side walls that absorb the impact of the ball, you will reduce the bouncing.
Replace the bouncing ball with soundwaves and you get the idea.
Sanjay, I tried a different approach. I used the REW signal generator to generate a sine wave at the predicted room modes (35, 58, 69, and 87Hz). I placed my RS SPL on my mono-pod so I could extend it up towards the ceiling as well as along the walls and floor. I then placed the SPL in the several locations where I could mount one or more of the tuned membrane traps (I plan on ordering four 24"x24" panels), measuring SPL while the sine wave was playing. The candidate placement spots are:
- Centered along the base of the front wall (all 4 panels)
- Centered along the right wall, close to the ceiling (all 4 panels)
- Centered along the right wall, along the floor but behind a couch (all 4 panels)
- At ~1/4 point of left wall, close to ceiling (1 panel), remaining panels at one of the other spots
WRT highest measured SPL, the base of the front wall produced the highest values, by 5-10dB. So, would it not be most effective to place the panels in the spot with the highest SPL at the targeted frequencies?
As a side note, the open floor plan that I have exhibits some interesting characteristics. For example, if I generate a sine wave at 58Hz (the second mode of the width), and move the SPL from the left side of the room to the right, I don't get the peaks and dips at the 1/4, 1/2, 3/4 points of what I consider the "width" of the room. The peaks and dips seem to be associated with the wider width of the open floor plan, which makes things much harder to predict. So, I'm back to a trial-and-error method of placing treatments, which is why I think the spots with the highest SPL are good candidates.
Here is the open floor layout that makes predictions difficult: