How to set gains with Piezo

[loudsubz]

Not specifically for Pro Audio, but I want to try this method for setting some amp gains on my boat. I read up on it but I wasn't sure if you had to use a regular 12vdc piezo or an actual audio piezo like the kind we use for the tweeter array. If it is one of the Goldwood units do you play a specific freq and when there is clipping (DC) in the signal the piezo will start to make a different sound?

[Bill Fitzmaurice]

Piezos are used to test for clipping with a 100Hz tone. When clipping is present there will be sufficient harmonics to be heard through the piezo. And there is no DC present in a clipped signal.

[loudsubz]

Thanks for that bill.

I was confusing DC with a clipped (Sqaure) wave signal.