I understand the 1 watt thing your saying but wouldn't it sound differant with 200watts from amp at any volume than 75 watts at any volume
I'm not exactly sure what you mean. A 200 watt per channel amplifier has about 4 db of headroom over a 75 watt per channel amplifier. That means it would start clipping at a volume level about 4 db higher than the smaller amp.
Clipping means the amplifier's ability to amplify the signal properly has been exceeded and it only transmits part of the signal and that results in distortion of the signal. Where does that point occur? Depends on the size of the listening room, the efficiency of the speakers and room acoustics, the composition of the speaker systems, the dynamic range of music and, of course, the amplifier power. It's pretty complicated.
I'll give you a real case, my own. My home theater is in a room that is about 20' by 24'. My main speakers are of average efficiency and they are supported by a powered subwoofer. I sit about 12 feet from my main speakers. I set my listening level so that I hear movie dialogue at about the same volume I would hear it if the actors were in the room with me. I have a recording wattmeter connected to my right front speaker. The average power input to that speaker is about 3/4 of one watt over the course of a movie. On loud peaks such as explosions in movie soundtracks, the watt meter will hit as high as 20 watts. What this means is that, in my situation, anything over 20 watts per channel is enough to drive my front speakers without distortion. No doubt the subwoofer needs a lot more but it has plenty of power by itself. We're talking about front main speakers.
My receiver has an output of 150 watts per channel. I chose it not because of the power output but rather because it did a good job of scaling SD programming. I don't use very much of the power since the powered subwoofer carries the heavy load.
The image below shows an amplifier I use to drive a public address system for live musical performances. It is rated at around 350 watts per channel into 8 ohms. I can fill an auditorium with sound from this amp driving two speakers. I could parallel two more speakers and produce even more volume since the amp is stable at low impedances. In my home listening room this amp would use more electrical power to heat its power supply transformer than to drive speakers. It would be a complete waste. Different situation, different application, different requirements.