I just finished acoustic treatment for control room and recording/rehearsal room. Btw. thanks for this forum, I got a lot of information about this topic. I would make a photo diary if there wasn't a big problem: I lost my cell phone with all the photos on it
But there are some issues left.
1. recording room. I got a good even RT60 of 0.5s in the midrange, and slightly more below 300 Hz with a tiny boost around 150-200 Hz (0.8s I think, I have the data on the other computer) . I added a slot absorber in one corner (all other 3 corners are superchunks) tuned to 150Hz middle frequency and it helped a little. The reverberation time of 150 Hz is decreased but still more than 0.5s.
Question: is this ok? Or should I add another absorber?
2. recording room: du to contruction issues some parts of the ceiling are horizontal. Especially over the place where we want to put the drumset. The flutter echos are annoying! So of course I need something to add on the ceiling ("clouds") but what? Due to the fact that we want to install fitted carpeting (I got this from a dictionary, but I hope you know what I mean) I have a decrease (of RT60) in the highs above 6 KHz. At present there lies old carpeting, so my measuring are nearly identical to the final result. My fear is, that the room will sound dull than.
Question: What to add above the drums to break the flutter echos without makinng the room dull?
Question: Does fabric on the absorbers significant lower the absorbtion of highs? Or should I install some kind of foil under the covering fabric? If yes what for? I tried a relatively thick foil and got strange results: the RT60 of 100-300 increases to 1s! I tried a very thin foil and the highs raised only a tiny bit.
3. control room: 4.20m length, 2.82m width, 2.86m height, flush mounted JBL LSR32
RT60 of nearly equal 0.2s with a slight increase below 200 Hz and a decrease above 6 kHz. (again: carpet floor).
What to add above my head on the first reflections points? I little bit bass absorbtion would be good so I think about clouds under the ceiling bend. (red)
On the sides I added 2x2 auralex 4" wedges (orange). Should I use abflectors or something instead, not to make the room dull?
The room has 4 superchunks. One on the rearwall-ceiling and rearwall-sidewall (inluding the room corner). Two others on the ceiling-side-wall-edges.
The rear wall is covered with 100 mm rockwool, the doors (even for optical reasons) with 4" auralex pyramides (I still had it left).
Question: What to add on the first reflection points (side and partly ceiling)?
Question: Does fabric on the absorbers (rear wall, super chunks) significant lower the absorbtion of highs?
4. control room
I have no resonance at 59Hz as expected. But in the rear half of the room is less bass, although on listener position it sounds nice.
I have some nulls in the room when I play sinus signals (40Hz, 50Hz, 70Hz, 80Hz).
Question: Live with that? Or what can I do?
Thanks Thomas