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wattage question

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=28342
Printed Date: August 17, 2025 at 8:25 PM


Topic: wattage question

Posted By: flatulatta
Subject: wattage question
Date Posted: March 14, 2004 at 10:14 AM

ok i know most everyone knows the watt formula amperage x voltage = wattage.... i was wondering how accurate this was for more amps because i tryed it and it showed me about 1000watts for my amp... i was assuming this was with full voltage and the least resistance but how relable is it exactally?




Replies:

Posted By: DYohn
Date Posted: March 14, 2004 at 10:18 AM
Ohm's Law is, well, a LAW.  It is 100% "reliable."  What are you measuring, exactly?  And what amp are you talking about?




Posted By: flatulatta
Date Posted: March 14, 2004 at 10:22 AM
well i was just messing around the other day and wanted to use it to see how many watts my amp put out and im running a 14.4v system and there is no rating for that anywhere..... i am running a jbl bp600.1..... it has 2 30a fuses in it




Posted By: DYohn
Date Posted: March 14, 2004 at 10:34 AM

Well, at 14.4 V and 60 A (30 X 2) the math comes out to 864 watts.  JBL under-rates their equipment so the listed specs are at a nominal 11 volts.  The BP600.1 (a very nice amp, by the way) has a max current draw of 57 amps.  So if you are really delivering 14.4 volts to it, it should be able to produce approximately (57 X 14.4) = 820 watts PEAK.  This compares nicely with their rating on the amp of 600 watts into 2 ohms.

If you are really interested in measuring the exact output from your amp, it requires a little more expertise and equipment than the average person has.  You can't do it with just a voltmenter, for example.  But if you're serious I can direct you to a web site that will show you how to do it.





Posted By: flatulatta
Date Posted: March 14, 2004 at 10:37 AM
yea thatd be cool as long as it didnt cost about as much as the amp or speakers  : )




Posted By: customsuburb
Date Posted: March 14, 2004 at 1:12 PM
So an old alpine amp like the 3513s which has a 10 amp fuse would average about 110 watts? Is that way off or am i about right?





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