John Woodgate jmw at
Fri Jun 6 17:12:40 EST 1997

In article <5n6gft$on1$1 at>, John Fields
<starship at> writes
>Arny Krüger (arnyk at wrote:
>: Luc.vanHoye at wrote in article <33935466.1CC at>...
>: > I am trying to figger out if the impedance of an audio device has
>: > something to do with how loud its signal can go...
>: It does not.
>: Impedance and sensitivity are separate specifications.
>It does.
>Consider an amplifier with an 8 ohm output impedance feeding 8 volts into 
>a speaker with an 8 ohm impedance.  The speaker will be dissipating 8 
>watts of power and will generate a specific sound pressure level.
>Next, consider the same amplifier putting 8 volts into a 16 ohm load.
>Since P = E^2 / R, the power being pumped into the load is 8^2 / 16, or 4 
>watts, which will yield a lower sound pressure level.
>The assumption, of course, is that both speakers have the same efficiency 
>and are, in fact, identical except for their impedances.
And that is called 'begging the question'. Youhave just assumed what you
purport to set out to prove!
Regards, John Woodgate Tel. +44 (0)1268 747839
Fax +44 (0)1268 777124. OOO - Own Opinions Only
Alternative e-mail address: jmwa at
That means I get double spam with everything (;-(

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