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Path: utzoo!linus!philabs!seismo!rochester!rocksvax!dave
From: dave@rocksvax.UUCP (Dave Sewhuk)
Newsgroups: net.auto,net.audio
Subject: Re: How do you get 60W out of a car stereo with 12 V????
Message-ID: <936@rocksvax.UUCP>
Date: Wed, 12-Oct-83 13:57:22 EDT
Article-I.D.: rocksvax.936
Posted: Wed Oct 12 13:57:22 1983
Date-Received: Fri, 14-Oct-83 08:11:03 EDT
References: <617@eisx.UUCP>
Organization: Xerox, Rochester, N.Y.
Lines: 23

Only 2 ways to exceed those numbers:
    1) Build a DC to DC converter to generate a > 12V supply for final
	transistors.  If done this way there is a possibility that some
	RF interference could be generated in the converter.

    2) Use a transformer to take "step-up" voltage going out to speakers.
	You can do this because the output impeadance of most amplifiers is
	low.  Always adds low frequency distortion unless there is a lot
	of iron in transformers. 1 required per channel.

I have seen those amps that claim 100W per channel and they are nothing more
than a redefinition of the term watt.  Algebraically represented as follows:
	Power(r) = V*I*r where is is a constant value usually much greater
	than 1, and named after its user.
I beleive they can stick any number they want on auto equipment.  The FTC only
has rules for advertising and specifying home equipment but car equipment 
is not under those rules.   Buyers beware!! If the unit is over 10W per channel
is must fall into one of those 2 categories above if there is any truth to 
their claim for power.

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Arpa: Sewhuk.HENR@PARC-MAXC.ARPA
uucp: {allegra, rochester, amd70, sunybcs}!rocksvax!dave