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

[Needham, Alan]

As a starting point, take a radio-controlled helicopter
Zip-tie it to your hi-fi
Set rotor speed to constant
Drive rotor pitch from amp out
Instant audio improvement !

	Alan

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of cheater
cheater
Sent: 21 July 2008 12:09
To: synth-diy at dropmix.xs4all.nl
Subject: Re: Rotary woofer (was Re: [sdiy] Brain filling in fundamental)

Yeah, this price is amazing.

But in true DIY spirit, I'm wondering if you could take a usual, good,
DC fan of some sort and modulate the speed with low frequency audio
signals to get similar results.

If you assume the fan is weightless and the speed change is
instantaneous, the pressure changes should be similar to what a normal
speaker would do (of course with the added advantage of a good
impedance match). Now to predict how the fan's weight distorts the
signal... second-order DE system, anyone? :)

Damian


_____________________________________________________________________
The information contained in or attached to this email is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are not authorised to and must not disclose, copy, distribute, or retain this message or any part of it. It may contain information which is confidential and/or covered by legal professional or other privilege (or other rules or laws with similar effect in jurisdictions outside England and Wales).
The views expressed in this email are not necessarily the views of Centrica plc, and the company, its directors, officers or employees make no representation or accept any liability for its accuracy or completeness unless expressly stated to the contrary.

Centrica plc

Registered office: Millstream, Maidenhead Road, Windsor, Berkshire SL4 5GD

Registered in England and Wales No 3033654