So here is a response i read from another post with the same question I was asking about external amping fronts and why I was leaning this way….
If your system has front speakers that can handle a lot more power than the effects speakers and your room is large enough the higher quality amp will be better sounding even if the power is the same as the receiver. Why?
The power of a surround receiver usually goes down drastically when all channels are playing loud. A 100 watt x 7 receiver might only produce 40-60 watts when the system is working hard. Separate power amps (even multi-channel ones) don't decrease in power.
A good power amp will usually sound better than the ones in surround receivers. Limited space for power supplies. Lack of high current to drive more difficult loads. Quality of sound is usually low priority with the makers. Features usually take precedence. Just so long as they reach the magic 100 watts on paper what happens in the real world doesn't matter because it's expensive to correct it.
Theoretically all the amp channels should sound the same. In real life the audio from the effects speakers is usually different than the fronts anyway. If you had identical speakers all around they would still sound very different because of placement and your listening position. This makes the amp not matching unimportant usually. If you have good speakers you can hear the center channel amp not matching the L/R fronts.
Using a receiver and adding a power amp for the fronts only is a good way to save some money. Preamp processors start higher than mid level receivers. A 7-11 channel amp will cost more than a 2 or 3 channel amp and there will be a lot of wasted power since most of the channels will be more than needed.
All receivers have variable preamp outputs. The different amounts of power are matched when you go through the setup procedure just as the efficiency and placement of the speakers is compensated forl
That seems like a generic response so by nature it is going to be mostly correct other than he got some minor things wrong. For example, he said "all receivers have variable preamp outputs, that is not correct. Also, he said separate power amps even multichannel ones don't decrease in power...I suppose he meant if all channels are driven simultaneously, and if so, that is not always the case.
Anyway, I thought your original questions have been dealt with, is there still some that you felt not answered yet? Again, to avoid generalizing, would you mind using one of those linked online calculator to figure out your actual "power" requirements? Once you get that figured out, it would be relatively easy to give you a more definitive answer to any power requirement related questions that you may still have.
Keep in mind that to gain 3 dB more spl, you will need 2X the "power", so a 200 W power amp will only let you crank the volume up by 3 dB higher without increased distortions, all else being equal. On the other hand, if you only need 25 W (8 ohms or 4 ohms) average, 50 W peak under the most demanding conditions then adding an 200 W or 500 W amps is not going to give you "better" sound quality because the internal amps happened to measure better than many separate power amps in THD+N, IMD, FR, SNR, DR, linearity etc..
There are the sayings, that "people don't realize how little power they actually need..", "people don't realize their amps may be clipping much more often then they know...", or "you can't have too much power.." All of them could be true, it depends on the context, and the specific case.
