As I said, for Karaoke you need a pro musicians type PA system like you would see in a bar, not a receiver and in wall speakers for sure. Mine might get away with it, but there is no commercial equivalent of those.
You are not the first poster here to blow up a domestic system with a Karaoke machine for shure. Live mics have a huge dynamic range. You could do it with a compressor limiter inserted, but they take skill and experience to use.