What happens when a signal clips (runs out of headroom, or hits a digital ceiling, or an amplifier runs out of power)?
Well, when a sound (such as a sine wave) clips, we start to see a corner that looks like a square wave forming. So what is happening to that sound? We know that the sharp corners on a square wave are high frequencies consisting of odd harmonics – which is exactly what happens.
So on the one hand, odd harmonics are not atonal, so as a signal starts to clip, the sound still could be pleasing / musical as it’s still related by integer harmonics – at the very least it’s not inharmonic!
But on the other hand, pushing that much power normally found in the low frequencies up into the higher frequencies which need/use less power is a formula for disaster.
Contrary to conventional wisdom, too little amplifier blows speakers. You can never have too much amplifier.
And now the term “total harmonic distortion” makes a lot more sense!