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Watt meter?

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=9196
Printed Date: June 21, 2025 at 4:10 AM


Topic: Watt meter?

Posted By: apc1
Subject: Watt meter?
Date Posted: February 07, 2003 at 8:36 PM

This may be a stupid question to some. I have researched the info. I need but cannot find a definitive answer. Is there a meter that tests the level of "Watts" an amplifier produces? If so, where can I get one and how much? Can it be used for auto and home theater?

Thanks in advance.



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If superman could stop bullets with his chest, why did he duck when someone threw a gun at him?



Replies:

Posted By: bberman1
Date Posted: February 07, 2003 at 10:14 PM

You can figure out the RMS on any voltage meter use the following formula. Set the voltage meter to A/C voltage....play some tunes and watch peak voltage....square this then divide that number by the impedance load. This gives a close idea of the RMS that the amp is putting out.  As far as a voltage meter that performs this calculation I have never heard of one. This can be used for both Car and home audio.  Hope this formula helps you out.





Posted By: fakepete
Date Posted: February 08, 2003 at 12:22 PM
There are actual watt meters out there, but they are usually rather expensive ($1000+).  The method posted by bberman1 will work.  You can also measure the current in the speaker wires and multiply it by the voltage, but this is only accurate at frequencys around 60 Hz.  The only other way I can think of is using a voltage and current probe on a dual-trace ocilliscope, but most people don't have one of those lying around either.




Posted By: apc1
Date Posted: February 08, 2003 at 6:30 PM

Gentleman, thank you for your prompt responses. I think bberman's method will do just fine for what I need. I am a Cable/Satellite contractor doing an audio system for a sports bar and need to calculate the ratings on certain types of equipment I will need. Your help is greatly appreciated.



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If superman could stop bullets with his chest, why did he duck when someone threw a gun at him?





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