This was the home stereo setup with the big SB-G400 speakers. Input power rated at 200W, and I don't have any specs for power beyond that. Connected to that 70W receiver, you're looking at a hospital stay at anything past half volume.It was probably 200W peak, which means it was more like 50W continuous. You want your amp to be at least as powerful as the continuous (RMS) rating of all your speakers combined, or when you have your volume turned up all the way, you'll burn out your amp and probably blow your speakers too.
Also, Pro (indoor) AV is a little different from Car audio, in that most cars don't have digital signal processors with peak limiting compressors to protect the speakers from too much juice from the amps, whereas we always do in our installations.