stevef

Tried to attach a pic but couldn't get it to work. Anyway I bought a pair of above average Black Birch, 1978 Heresy's a flea market this past weekend for 75 bucks. All original and sound great. No grills so the woofer cones are faded.

The slot loads the throat of the horn.. so, just enough space to keep the woofer diaphram from striking the baffle board. If you have the Xmax spec from the woofer, use that plus a couple extra millimeters, and that should work. Also, make absolutely sure that you have NO AIR LEAKS anywhere. Good Luck!