I've got no idea on your question, but he's done Altec recones before, and I think has used GPA parts....... Although, maybe not exclusively. Dgwojo (or whatever his screen name is) I believe used him. I'm under the impression that he knows what he's doing, but it's been so long since I've heard details from those that have had work done by him, that I can't relay much anymore.
One of these days I plan to have him take a look at an 8" Radian coax.
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