It’s always fun to work with electronics, so I do that too! One of the areas I am working on is sound — and everything that happens around it. Over time, I have collected all kinds of speakers, and most of them hang idly on a wall.

In the past, I built a speaker resonance meter with the help of an oscillator, a voltmeter, and a frequency meter. The loudspeaker could be driven with a constant current, making the resonance peak very sharp. You had to vary the frequency manually, while keeping an eye on the voltage at the same time.

That testing gear worked fine, but its usage wasn’t very straightforward. The project described here does not have that limitation. In fact, I decided to design an automated version of it, based on an oscillator whose frequency is determined by the loudspeaker itself.

The Idea

The intention was to use an Arduino-based frequency meter to measure the resonance of a loudspeaker that is included in an oscillator circuit, and to feed the whole design...