I couldn't use BNC's there is not enough space between the existing hole to mount the style I have in the parts stash. I could not get the part from Klipsch, they wanted to sell me the whole plate amp for $220 Dollars. I don't think so, they wouldn't even sell me a service manual something about copyright BS. So I went to Mousers and ordered replacements, they are much better in quality then what Klipsch install to begin with. I really favor Switchcraft for parts like this. What I purchased was rear chassis mount RCA jacks.