I agree with Alan's and Jakeman's posts on distortion. As I mentioned, I didn't have the necessary equipment to conduct distortion measurements. This was a "poor engineer's" characterization
. One day, I'll borrow a scope to satisfy my curiousity.
It's worth noting, again
, that I keep my Denon at -25 for music and around -20 to -15 for movies. This translates to about a half watt to 2 watts (measured under a different experiment). So when listening to movies, this gives me about 22dB of headroom and music 16dB of headroom (referenced to 90W). This is more than enough headroom. Now admittedly I don't know for sure if my receiver is clipping at 90W but I certainly don't hear any clipping. BTW, these power levels translate to 80 to 90dB SPL in my room.
Another item worth noting is the effects that high power have on your listening experience. Higher power to your speakers translates to more heat that must be dissipated. Speakers are not heatsinks and they are not terribly efficient at cooling themselves. The sinister aspect to this is that as the voicecoil temperature rises, its resistance increases. As its resistance increases, the power to the speaker goes down. As power to the speaker goes down, SPL decreases. So now a "portion" of your high powered amplifier is acting as a heater
. The question of course is to what degree? If you are putting 300W into a speaker, is 150W going into heating? I'd need to work the math out on this one.
And now something even more sinister. Ever wonder what happens to the speaker's passive cross-over design with these heating effects? Very simply, the cross-over frequencies will shift with volume.
And there are also deleterious effects on the magnetic circuit...I won't go there
.
Most of us need not concern ourselves with these worries. But there's a few out there that may want to take note. Those that want more power may not only need a larger amp. They may also need larger speakers. And perhaps even active cross-overs. And ear plugs
.
