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Old March 5th 05, 07:16 AM
John Woodgate
 
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I read in sci.electronics.design that Tom Ring
wrote (in ) about '1/4 vs
1/2 wavelength antenna', on Fri, 4 Mar 2005:
John Woodgate wrote:

I read in sci.electronics.design that Tom Ring
wrote (in ) about '1/4 vs
1/2 wavelength antenna', on Thu, 3 Mar 2005:


He forgot to mention that for that output impedance to be relevant, you
need superconducting wire to the speakers as well as superconducting
voice coils.



See the last sentence, about the effect of an **8 ohm** source impedance
on damping.


Oh, and going from 8 ohms output impedance to 10e-7 (unless I
miscounted) would take the damping factor from 1 to 8e7, which is a bit
more than 2. Ignoring the speaker wires of course.

Also ignoring the ***voice-coil resistance***. If that is included, as
it must be for a correct analysis, you get 2.

F Langford-Smith 'invented' the concept of damping factor, and around
1949 accepted the point made by James Moir that, by not properly taking
into account the effect of the voice-coil resistance, it was a seriously
misleading concept. Yes, 60 years later, people are still being misled.
--
Regards, John Woodgate, OOO - Own Opinions Only.
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http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk