desper,
for box speakers. For bipolars I have no idea as the back wave is out of phase. I will have to think about the math on it.
Macg19,
good to hear it worked out. those distances are based on wave lengths and the speed of sound. What ever the distance is from the wall times 4 it will cancel at that frequency. So 5’ is 1/4th of 20’ and that works out to 57hz (57hz has a 20’ wave peak to peak) right at where kick drums get their weight. Keep in mind it is the center point of the bass so if you have rear ports that center point is the sum of the port and driver… at least at the port tuning point.
I use active crossovers so my speakers are highpassed so it it a bit more complicated as both sub and speaker distances matters. Those pictures of my system the speaker is 43” from the speaker face and 24” for the subs when using an 80hz crossover. I am using a 60hz now and have them out 4.8’ to accommodate that (I should update picture I guess).
the room clutter might hurt a bit. The screen between my speakers is “acoustically transparent” screen from Screen Innovations. It is said to drop 6db starting at 2khz though audioholics measured it at closer to 10db. Regardless I have A/Bed it up and down and it is really hard to tell a difference. The JBLs are very directional at 2k so it might be moot. My real issue is the low ceiling which causes problems at 40hz. I turned my whole ceiling into a bass trap (cost $3k and about a month of work), I also have 9 bass traps in the room. It helped but still not great without room correction which I try to avoid these days. I am +/- 6db now… sounds ok.
