This post focuses on the use of piezo sensors and pickups in pro audio applications.
Most people don’t think of piezo technology very often. Basically, piezoelectric sensors involve using mechanical vibrations against the sensor to create a signal. It’s a unique way to generate sound and signal, meaning that it can be used in applications where traditional sound capturing devices don’t work well. In fact, sometimes piezo sensors are called contact microphones. Some common applications include acoustic guitar pickups and drum triggers, but there really is no reason why you couldn’t use piezo sensors anywhere that produces vibration (and therefore, sound).
Basically, the piezo sensor is composed of two plates that vibrate. When the plates get closer, voltage is produced. See the fun animation to the right…
One particular advantage of piezo pickups is that they don’t have the sort of leakage problems of microphones. That is, generally they only pick up the sound of the instrument to which they are attached. This can make them ideal for sidechaining gates. Consider the advantage of using a piezo pickup on a drum to activate the gate applied to its miked signal…
Also, piezo pickups have a very defined transient response, making them good for augmenting acoustic recordings. One popular thing to do with a piezo pickup, in a recording context, is to record an acoustic guitar with both a microphone and with a piezo pickup. The blend between the two sometimes sounds better than just one or the other.
Piezo also has a very unique, woody sound that can produce some interestingly lo-fi results. Try putting a piezo on the underside of a grand piano for an weird, ‘bonky’ tone.
Piezo can also be used to create DIY drum triggers. Check out this guide for more information on DIY triggers. Piezo can be used on acoustic drums as well, both for triggering, for tone, and for sidechaining. This guide details how to get the most out of acoustic piezo drum triggers.
You can find inexpensive piezo pickups in many electronics stores. Do some experimenting. You might be surprised what you can do.
Check out this HowTo for DIY drum triggers!