DIY Absorption, What Next?

[Glenn Kuras]

Straddling the corners is going to help, if nothing else further lowing the decay times below 100hz (very important). But the dip you have could be as easy as moving the speakers. Once you have your mic back test each speaker and view that first. It could be as easy as you don't have the speakers set right in the room. You could also try some thick panels behind the speakers and or on the side walls by the speakers. There are a lot of places it could be coming from.
When you say a dip, how much? Keep in mind that if you can get the frequency response (on the low end) +/- 8 db you are going well.

[Jens Eklund]

Originally Posted by spz

Thoughts?

As always:

4m x 5m x 2.5m room - modal resonance problem

[kasmira]

I think making two floor to ceiling corner straddling panels may help low frequency quite a bit. Re-reading an old post, I believe it is quite useful to have panels where sound has no choice but to go inside and be absorbed. Sound is usually forced into corners, but even moreso making floor to ceiling traps in the corners, it can't leak out from above/below the corners. Perhaps make two however tall corner traps and place your current corner traps in the ceiling corners?

[Glenn Kuras]

but even moreso making floor to ceiling traps in the corners, it can't leak out from above/below the corners.

Kind of but it is due to now covering tri corners which picks up more low end. I guess you could say "leak" but I wouldn't want people to think that broad band is sealed in anyway.