I just received my R-1650-CSM speakers in the mail. There are two pairs of input connections. I can't for the life of me find out which connections to use. The literature that came with them simply tells me to connect them to my amp. I can find nothing on-line and Klipsch Support tells me to wait up to 7 days for them to respond... Grrrrr
I put a 13 gallon trash bag in the speaker hole then sprayed expanding foam into it and sealed it with a rubber band. I tucked a pillow into the hole to achieve a convex void until the foam hardened. It's not perfect, but I got good results.