Clipping is when the amplitude of the output signal is bounded by some maximum value, and attempts to exceed it. E.g. a voltage signal needs to be higher than the "rail" voltage (i.e. the supply voltage). Or a high current drain that cannot be supported by the supply and causes the supply voltage to "dip".
It is purely related to the amplitude of the signal, and is called clipping because the resultant waveforms look as though someone gave them a haircut (e.g. sine waves with their tops flattened).
While clipping is a signal amplitude phenomenon, it does have significant and potentially damaging spectral results.
Quote:
The reason most stores and alleged gurus tell you that clipping kills speakers is because most people coincide speaker value and attaining the maximum heat or excursion capabilities of the speakers. That's what the Rane publication shows." |
Clipping DOES kill speaker systems (which use a passive crossover network), not because of the maximum heat or excursion capabilities, but because of the spectral content of the signal.
Clipping causes a "rounded" square wave to be formed, which has harmonics at very high frequency. Unfortunately, the attenuation of these harmonics is very low (and does not exist for true square waves). Tweeters can take between 1%-10% of the total energy supplied to a speaker system (depending on the crossover frequency). A low frequency sine wave that is clipped will have a comb of high power odd harmonics. These harmonics will be routed to the tweeter by the passive crossover, potentially frying the "power shy" tweeter.
Where did the quote come from? For car systems, it is customary to wire individual speakers to individual amplifiers, and using an active crossover. In that case, clipping of a woofer amplifier will affect only the woofer and will not damage the tweeter (which is connected to a separate amplifier).