Common convention here is to build lots of absorption behind the mains to abosorb the omni radiation of the mains as best as possible. Many do this out of covenience or other restrictions. I'm not contstrained by those and want to explore how to get a ruler flat midrange without the Allison effect causing its normal disturbance for speakers ~20" off the front wall.
I will be building 2 way controlled directivity speakers soon and they will not have baffle step compensation incorperated into the crossovers.
Baffle walls. They effectively make the speaker radiate into half space and do solve the Allison effect causing time/phase issues above the calculated frequency the baffle wall reflects which is dictated by the baffle size and its thickness/density.
I've read some of John Murphys writeups based on Harry Olson's work. From their formula it seems a 4'X4' piece of 3/4" plywood "baffle" should reflect the frequencies above 95Hz, with 95Hz actually being the -3db point.
F3 = 380/W
W= Width of baffle in feet.
F3= -3db point
If I cut a 4x4 piece of 3/4" plywood, cut a hole for speaker, insert speaker, and attach to my Acoustically transparent screen wall, the speaker should radiate half space according to this calculation correct?
Is this a silly quest or should I just load up the front wall with absorption?
What other concerns are there?
Don't waste time reading signatures.....