The space left between the sail panel and the mounting is about 1/2". I procrastinated over a variety of mounting options: Surface mounted, make a custom pod, half-buried in a cup etc. Finally, I believed this to be the most elegant and inconspicous option. Carefully drilled a 1 1/2" hole, marking the center drill from the inside, and then very slowly drilling from the outside.After sanding and deburring, the tweeter was inserted from the inside and gently pushed into final position. This is a very nice and tight fit, not requiring additional support. Just to completely anchor, I applied a dap of two component epoxy paste. If I ever need to change the tweeters out, the sail panels are cheaper than any labor involving a custom pod :-)