You wrote:

>> Push pull mounting would cancel the second H (like using a push
>> pull transformer vs single ended) however of all the harmonics the
>> second is the least objectionable. That’s no reason not to do it
>> how ever.

Yes, that's what the shorting ring on a high-quality loudspeaker does too. That's why I asked Eminence to build the B12. The push-pull arrangement might actually work better at low frequencies though. We'll see.

As for the expansion of the room from the corner, I did some math and found it to be conical (of course) until the ceiling junction is reached, and then it becomes roughly parabolic. For visualization purposes, I compare the area expansion at different distances from the apex with a rectangular horn having straight walls in the post called "Room Corner Characteristics." I use this feature in some of my designs, but it isn't particularly germane to this particular horn. The horn I'm looking at right now is a high-power horn that probably won't be used in homes and its main feature is the push-pull plenum prior to the throat.

Wayne

The original LABsub has a compression ratio of 2:1. I have a modified pair at 3.0 compression ratio.

1 dB is .0000000029 psi
15 psi would be: 20log(15/.0000000029)= 194 dB

The actual peak horn throat SPL is more like 155 dB which is 0.2 psi.

What do you have in mind as the top end of the effective FR?

Cheers