I tried it years ago. It seemed like a simple process to do. I put a 3 channel amp/processor in the tape loop of my 2 channel system. And, of course the rear and center channel speakers.
It was OK at best & complicated as he** to operate with the various remotes & routine to setup for home theater. My wife hated it because she didn't know which buttons to push and when. I was & am really more into 2 channel anyway. So I abandoned the idea a yr or so after setting it up. Now I just have 2 channel home theater when needed, most always for concerts. Much simpler. Sounds great with concerts. We're both happy
It was OK at best & complicated as he** to operate with the various remotes & routine to setup for home theater. My wife hated it because she didn't know which buttons to push and when. I was & am really more into 2 channel anyway. So I abandoned the idea a yr or so after setting it up. Now I just have 2 channel home theater when needed, most always for concerts. Much simpler. Sounds great with concerts. We're both happy