Motor + PA Amplifier= Speaker?

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I just did a quick experiment where I attached a DC motor to a cardboard box and then hooked the motor to a PA amplifier. Just turn the volume way up, and see what happens!

Here’s what I used:

  •  A DC motor (very common)
  •  A cardboard box (also very common)
  • A PA amplifier with a 4Ω speaker output*

Simply hook the 4Ω and common outputs on your PA amplifier to the inputs on the motor. Poke holes in the box and put a zip-tie through them. Use this to hold the motor to the box. That’s it! Just turn the volume way up and hook up some kind of audio playback device.

To see this in action, I made a video

*To substitute for a 4Ω speaker output, put a 4Ω resistor in line with the motor.
The motor
The PA amplifier

4 thoughts on “Motor + PA Amplifier= Speaker?”

  2. Dennis and Hannelore Hess's avatarDennis and Hannelore Hess

    Owen, what a wonderful experiment! Can’t say that the resulting sound is “high fidelity”, but it is amazing non-the-less. –Nana and Papa

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    1. Owen's avatarOwen Post author

      Definitely not high fidelity, but it could sound a lot better with a bigger motor. I just didn’t want to risk damaging my amplifier.

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