What’s your percentage? Distortion is commonly expressed in
percentages. Calculating it is a complex mathematical operation
(explained in depth here), but to put it very simply, 1% THD is
-40 dB below the original signal, 3% THD is about -30 dB below,
10% THD is -20 dB below, and so on. This tone demonstrates how
different levels of distortion sound. (Better put on your
headphones for this; lower-level distortion will probably be
hard to hear on your computer speakers.) The first 3 seconds is
an undistorted 400 Hz tone. The next 3 seconds is the same tone
at 0.5% THD, which some people can hear and some can’t. The next
3 seconds is at 1% THD, which most people can hear. The next is
at 5%, which anybody but Ted Nugent can hear. The final 3
seconds is at 10%, which sounds so grating because it’s your
amplifier’s last desperate plea for mercy. Now when you see an
amplifier’s power specified at 0.5% or 1% THD, you’ll have some
idea of the real-world implications. While I was making the
tone, I also monitored the