Sorry it took so long to reply.....just joined this site recently. I designed the SPL loudspeakers. The speaker in these was an SPL 915R. 96 oz magnet, 3" voice coil, cast aluminum frame. I think we rated these at 300W, but they actually fail at about 700W continuous RMS pink noise. They run nicely off a 1000W @8ohm amp. I think the P/N might have been 81-0915. I'm surprised the original speakers aren't still in it, they were pretty hard to kill. You can replace them with any 15 you like, the bigger the magnet assembly, the better.
