Date: Wed, 27 Apr 2005 02:44:35 GMT From: "James Sweet" <jamessweetnospamail.com> Subject: Re: I think I blew my amp??!!
> > 1. The amp's power rating will be at a certain, reasonable, distortion > level - say 5%. That 5% distortion doesn't happen *at* the clipping > point but some way before it. So you can drive the amp harder and get > more power than it's rating, but it sounds crap so the manufacturer > can't make any claims about this higher rating. > > 2. If you then continue to drive the amp harder still, and into real > clipping, the resulting sharp edges on the output waveform mean the > amp is generating much more power at high frequencies than it would > normally. The tweeters in the speaker system would normally only > expect to see a small fraction of the amp's output, so when the amp > starts producing serious power in the tweeter's range, safety margins > can get eaten into. > Actually it's more the rating of the *speaker* that's the issue. A 140W speaker will not handle 140W anywhere near continuously, that rating is music power, which assumes that the average RMS power is much lower. When an amplifier clips hard the output is much closer to DC at the *peak* power of the amplifier which is substantially higher than the RMS. If you don't believe me, take a speaker rated at 140W, assuming it's 4 ohm, connect it to a 24V DC source (which will cause it to draw about 140W) and see how long it takes the voice coil to smoke. You probably won't get more than 10-15 seconds out of it. Tweeters usually go first, but I've seen *many* speakers damaged by an underpowered amp clipping, if you open one up the voice coil is blackened.
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