Originally Posted by Heinrich S
So if the amplifier is clipping at 10 watts then it's not going to be 10 watts anymore?
an amp is RATED at some power at some set specified distortion level. That RATING does not cause the laws of physics to stop operating, or keep the amp from making more than the RATED power at higher than the RATED distortion.
I think I've come close to begging you a couple of times to go look at some power versus distortion curves in amp reviews. like this http://www.stereophile.com/content/dan-dagostino-momentum-monoblock-power-amplifier-measurements
. Go there and scroll, if you have the strength, down to figure 5 and you will see how, for that amp into an 8 ohm load, distortion (actually noise plus distortion but noise isn't a big part of the picture once you get to clipping level). It hits 0.1 % distortion at just over 200 watts. Can it output more power? HECK YES. 1 percent distortion at 400 watts. See? If I rate the amp at 1 percent distortion, I call it a 400 watt amp. If I rate it at .1 percent distortion I call it something like a 230 watt amp. What I call it doesn't change what it can do in terms of power above the specified distortion level. And BTW while 1% is about as high as you'll see specified, it's pretty much inaudible distortion. That is, an amp specified at 1 percent distortion can output more than its rated power before its distortion becomes even slightly audible with most typical real content. YOu could call htat relatively conservative specification practice.
Returning, if you are able, to figure 5 of the stereophile amp test, you will see that the distortion axis tops out at 3% distortion, and power is still increasing, but not as fast as distortion. It's just a bit over 400 watts at 3 percent distortion. Did the graph end at 3 percent because the amp blew up? No. They just had to stop it somewhere. The fact that the graph stops IN NO WAY means that the amp cannot put out more power at higher distortion. (If this utterly confuses you, you need to buy the semiancient book How to Lie With Statistics before you are ripped off any more by transparent misrepresentations of data in marketing materials of all kinds). Power will keep going up and so will distortion, but we cannot accurately predict what the power will be at 5%, 10% or 20% distortion because the curve/line might change slope further. So you only know what you can actually see. But for most purposes 1 or 3% distortion is considered max for home audio reproduction (Stereophile sometimes relaxes its 1% clipping number to 3% for tube amps in part on the gronds that tube distortion may be more subjectively benign than solid state distortion).
SEE? Power can go way up even after the amp is said to be clipping. Because "clipping" is a semiarbitrary point on a line that slopes upward in both power and distortion. Calling a point on that line "clipping" does not cause the rest of the line to vanish into a black hole. The performance, and its graphical representation, remain even well above whatever distortion level you want to call clipping. Perhaps the ungodly expensive monoblock being tested in Figure 4 could be specified at 700 watts at 10% distortion. We can't see the test results that high, so we don't know. Maybe it's 500 watts or less at 10 percent distortion. We don't know. But we know it will make more distortion (recall guitarists thingk 10% distortion is "clean") when you increase th input level, and that it will simultaneously produce more power.
You can see similar testing of other amps (assuming you retain teh capcacity to get to the link and scroll down on the page, here http://www.stereophile.com/content/anthem-statement-m1-monoblock-power-amplifier-measurements
and here http://www.hometheater.com/content/denon-avr-2313ci-av-receiver-ht-labs-measures
(a Denon receiver being tested. It makes 95 watts at about .003 % distortion, 150 watts at something between 0.8 and 0.9% distortion, and about 165 watts at 2 percent distortion.
All amps behave similarly. Once distortion starts rising, added input yields both more power and more distortion. at the levels we are talking about, the distortion is not adding any significant amount to total power.