From: John Woodgate
Subject: Re: wattage meter exists??
Date: Sat, 7 Sep 2002 11:21:08 +0100
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Sat, 7 Sep 2002 10:48:57 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Robert Baer
wrote (in <3D79ACA8.CE5E286@earthlink.net>)
about 'wattage meter exists??', on Sat, 7 Sep 2002:
>John Woodgate wrote:
>> I read in sci.electronics.design that Bob Wilson > pam.bc.ca> wrote (in ) about 'wattage
>> meter exists??', on Fri, 6 Sep 2002:
>> >In article <firstname.lastname@example.org>,
>> >email@example.com says...
>> >>Hi! Is there any device such a wattage meter that exist?
>> >>How much and where?
>> >Of course there is! I have a nice one that reads accurately both real power
>> >(wattage) and apparent power, from nearly DC to well above 100HKz. More
>> >standard ones that work at line frequency have been around for almost
>> Yes, but will it measure the 'wattage' of the sound from a 650 W PMPO
>> computer sound system? (;-) We don't quite know what the OP has in mind.
> Well, if all one wants is an estimate of power out of a sound system
>(and that is all that is done to get those "specifications" and
>sometimes less), then use a resistive load of the proper impedance (eg:
>8 ohms, 16 ohms, whatever the speakers or headphones are supposed ot be)
>and measure the voltage across each resistor at the specified inoput
>drive level; usually 1Khz is used, but 440Hz is OK also, as power levels
>are almost never guaranteed over a specified frequency range.
> Usually a frequency response is given with no directly stated link to
>the power level specified, and power level is just that - with no
>frequency involved at all.
Yes, I am sort of rather familiar with all that, but notice that I wrote
'...'wattage' of the *sound*...'. A sound power meter is very different
form an electric power meter.
> There is a lot of stupidity and false implications involved with most
>"specifications" of audio amplifiers made to drive speakers and/or
> There have been some exceptions to this generality, but the makers of
>that equipment had a lot of integrity and really cared about their
>products and customers.
> Virtually all audio stuff made for computers is cheap crap, some that
>seems to work well, but junk nonetheless.
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
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