I built Thorsten's Afterburner but am now going to try the Beta12LT in a PI cabinet.

Thorsten used an Extended Bass Shelf alignment (EBS) which is in the oposite direction compared to Wayne's alignment. It should make a nice comparison.

Do you have the Rat Shack tweet? I found them too bright--could be too sensitive or the 1st order crossover isn't attenuating quickly enough so there's too much overlap at 8-10kHz.

I'm going try a piezo tweet with a second order crossover.

Good luck and please let us know how it goes,
Cheers,
Jeff