Front wall prob / question

This matter is probably addressed in another thread. If so, sorry. I have a finite number of absorber panels made. All are 4-inch thick, 2foot by 4foot inside a wooden box. Better yet maybe the thread I started will get a better answer.

I guess it doesn't matter.

eh? maybe start with 1 absorber spaced between the speakers? or if you have enough, 1 behind each?

It's coming along well. I still have no internet so I can't upload all my pictures yet. I just want to do it right. I saw someone treat their front wall with two 4x2 broadband absorbers arranged vertically, one behind each speaker, leaving some bare space between them. Then someone else did it with one long horizontal one 8' wide and 2 feet high. If you had two 4'x2' broadband absorbers reserved for the wall behind the speakers, how would you position them?

i would put them behind the speakers

This might be the last question :-)) 1. I calculated (and did the mirror test) to mount the sidewall absorbers to the left and right primary reflection areas. Question: is the overhead cloud the same distance from the front wall as the left and right ones? Thanks in advance.:-) Mike

if you stand on the ceiling with the mirror you can use the same trick as the walls :twisted: otherwise it's usually just a bit forward of the side ones depending on how high your speakers are mounted. if you have your speaker acoustic center at (say) 42" in an 8' high room, and the front of the speaker is 12" off the front wall, assuming a 30 degree angle for the HF, then your reflection point on the ceiling is roughly 3'7" and the floor reflection is about 3'.

Glenn, On the walls I used a french cleat type of mounting, so edging them forward and backward won't present a problem if needs be. The ceiling however, edging them won't be as easy. When you say "the cloud will be just slightly FORWARD" of the side wall absorbers, I'm hoping you mean "just slightly closer to the listening position". I'm coming up with a location for the cloud that's a few inches closer to the listening position than the side wall absorbers. If that's what you mean, I'll hang these suckers right now. In my room: Distance from listening pos to tweeter = 46 inches Distance from speaker's acoustic center to ceiling = 55.5 inches Distance from my ears to the ceiling = 48.5 inches Ceiling height = 96 inches (8 feet). When i did the mirror test for the clouds, i had a mirror attached to a pole and slid it across the ceiling while seated in the mixing chair. I marked the reflection area's center at 47.5 inches (about a foot further from the front wall than the side walls' mirror test. Is there a formula for this? Because after decoupling these speakers or putting then onto pillars, their height will nodoubt be different than this. Mike

you're on site so if you're measurement says closer to listening position - then go for it. i was just making a general calculation for an 8' ceiling with speaker acoustic center @ 42in from the floor. etc. for actually calculating it - you can use this approach which computes the position of "phantom" source by drawing a line from the true source through the wall boundary - mirroring.