Rotary woofer (was Re: [sdiy] Brain filling in fundamental)

[Paul Perry]

For at least part of the operating range, the air flow (and hence pressure
generated) is reasonably linear with RPM for a fan.
So a motor speed controller could be used for your DIY infrasound generator
- plus, it won't infringe the patent.

If you want greater precision, you could use a pressure sensing cell to
derive feedback. Pressure cells go down to DC.

I hope nobody thinks of fitting one of these to a car....

Paul perry Melbourne Australia