Hydrogenaudio Forums > RotoSub: modulated fan --> bass

Full Version: RotoSub: modulated fan --> bass

Hydrogenaudio Forums > CD-R and Audio Hardware > Audio Hardware

Gecko

Mar 13 2005, 20:19

I just stumbled upon this at the heise.de newsticker.

http://www.swedish-ip.com/RotoSub/index.html

QUOTE

Short technical description
The principle of RotoSub is to use wings in a rotating fan/turbine configuration to generate sound. The angle of the wings is modulated by the sound signal and doing so modulates the sound pressure. Each rotation during the pressure cycle will act as a new "cone" area and doing so will extend the active "cone" area.

They claim high afficiency at low frequencies. They see the applications in PA active noise cancellation systems.

I have no idea if these things qualify anywhere near hifi.

breez

Mar 13 2005, 21:26

That's one big mofo!

Klyith

Mar 14 2005, 12:28

Bizzare. I can see how a fan or other pressure-generating device would be able to generate soundwaves just as well as a speaker-- after all, it is just about moving the air. But I can't figure out how the thing would be able to generate anything other than pure tones. A fan can't rotate at multiple rpm like a speaker cone can vibrate at multiple frequencies.

Gecko

Mar 14 2005, 17:08

QUOTE (Klyith @ Mar 14 2005, 01:28 PM)

The angles of the fan blades themselves are modulated. In this way you can move the air inwards and outwards while the rotation remains constant. Do that fast enough and you have a speaker. Pressure Graph.

This gadget is currently on display at the CeBIT in Hannover, Germany. I can't visit though.

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