Thanks on the tip, tried this already. I was using a set of Rockford Fosgate R165X3 Prime Series. I can fit them with the lower two screws inserted but because the coil and magnets are large, I think there is definitely a clearance problem. Both sides on the top sit too far out to get the other set of screws in, and the plastic cover doesn't seem to want to settle properly like that. All good, it looks like the JBLs fit without too much finagling.