Lee
07-16-2002, 06:16 AM
5.22 Why is distortion harmful to my speakers? [RK]Distortion is hard on speakers for two reasons.
Reason 1: Distortion causes the power spectrum to shift upwards in frequency. A bass note, when distorted, will have lots of high frequency energy. This will cause mid-ranges and tweeters to fry, if the amplifier is operating full range. It doesn't harm woofers, necessarily.
Reason 2: Distortion causes the average power to be much higher. Typically, a music signal that never clips has an average power level of 1/4 the peak power level for even the most compressed speed metal or pop. More dynamic music will be 1/8 the peak level or less on average. When you clip the amp hard, the average output moves up to the full-rated output of the amp or more. The peak to average ratio can be less than 2 to 1, with the peaks being at double the rated power of the amp, and the average being at the rated power of the amp or higher.
Thermally, the speaker can handle the average power being 1/4 the rated power of the amp (little to no clipping), but it will have a much harder time with the average power being the amp's rated power or more (massive clipping). As you might expect, this is pretty hard on the amp, too.
For transients, most speakers can handle a ton of power. But for long term signals, the power handling is much less.
Reason 1: Distortion causes the power spectrum to shift upwards in frequency. A bass note, when distorted, will have lots of high frequency energy. This will cause mid-ranges and tweeters to fry, if the amplifier is operating full range. It doesn't harm woofers, necessarily.
Reason 2: Distortion causes the average power to be much higher. Typically, a music signal that never clips has an average power level of 1/4 the peak power level for even the most compressed speed metal or pop. More dynamic music will be 1/8 the peak level or less on average. When you clip the amp hard, the average output moves up to the full-rated output of the amp or more. The peak to average ratio can be less than 2 to 1, with the peaks being at double the rated power of the amp, and the average being at the rated power of the amp or higher.
Thermally, the speaker can handle the average power being 1/4 the rated power of the amp (little to no clipping), but it will have a much harder time with the average power being the amp's rated power or more (massive clipping). As you might expect, this is pretty hard on the amp, too.
For transients, most speakers can handle a ton of power. But for long term signals, the power handling is much less.