The piezo horn tweeter

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Staff member
ODJT Supporter
Nov 10, 2006
Ventura County, CA
Remember speakers that used these?
These speakers don't have voice coils like traditional speakers. They use a piece of crystal (often quartz or barium titanate) that flexes when a voltage is applied to it. Piezos are very efficient at converting electrical energy to sound. They just don't do it with much quality. They have poor frequency response and high distortion. Nevertheless, they get loud and they are cheap. It was not uncommon to find PA speakers using 3, 4, or more of these. Another advantage is that they are capacitive and thus could be used without crossover networks making speakers that much cheaper. In fact, Pyle still sells speakers using these horns (see below).


The most common horns were the Motorola KSN1005A. Motorola made police car radios, bullhorns, PA systems for emergencies, etc. Volume was more important than quality. I always knew when I saw such speakers in use that I would have a headache by the end of the night. Nevertheless, I had such speakers in HS.