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True watts?

Posted: Tue Oct 19, 2004 2:57 pm
by daykareboards
My dad just got a Rockford Punch P2002 amp and in the box was a paper showing that the amp was tested and it tells how many watts rms and max the amp puts out and such. what tools do they use to test this and is it available to buy? i hate guessing what i'm putting out because i'm not caught up on ohms law or anything...

Posted: Wed Oct 20, 2004 4:56 am
by Jszar
yes they are available to buy. but the meter is about $1000.

its like a super multimemter. there are many ways to calculate power and current and voltage, but with car audio, the current and wattage is too high for normal multimeters to read. the highest a normal multimeter can read is 10A, and they dont even measure power. but you can find voltage with the multimeter, so you can use formulas to gather the info you dont have.

if you are ok at math, i can give you a bunch of formulas to calculate accuratly that info, without anything but a multimeter (+ pen and paper), but its probably easier to just get it checked at a shop for $10.

Posted: Wed Oct 20, 2004 4:58 am
by Jszar
**the only thing you cannot calculate is dB's! i'm not sure if that was part of your question or not.

to get an accurate read you have to have the car tested in a shop with a special meter. this meter is very expensive as well, but i'm sure you could buy.

Posted: Wed Oct 20, 2004 5:15 am
by Ryan from Ohio
If you get the right meter you may be able to do this cheaply.

You can set it to AC volts and get the RMS value on the volts coming off the amp.

Then if you get one with the clip on amperage tester you may be able to clamp over a SINGLE speaker wire, just the + or - then calculate it out to get watts RMS.

Posted: Wed Oct 20, 2004 7:01 am
by William from NOLA
Ryan, have I ever told you that I love you?

*runs out to car* *is glad he has a multimeter kept in it*

Posted: Wed Oct 20, 2004 7:17 am
by Ryan from Ohio
Not sure if it will work, just an idea.....

Let me know if it does though....

Posted: Wed Oct 20, 2004 12:31 pm
by William from NOLA
My multimeter doesn't support amperage above 10 A, so I didn't want to really try. Plus I couldn't figure out which one to stick it on. I tried one and the wire sparked to the + when i connected it and the wire got hot (after it sparked, i pulled it off, then did it again to make sure it wasn't anything else, felt the wire get hot so I stopped -no fires now :) )

Posted: Wed Oct 20, 2004 4:11 pm
by daykareboards
Jszar, i'm pretty good in math, highest i've had is trig. so if you can throw those formulas my way- Thanks

Posted: Thu Oct 21, 2004 3:06 am
by Ryan from Ohio
Ummmm for ampoerage I said to use a clip on meter.

Otherwise the little cheapies like we got you have to actually put them into the circuit.

Image

Thats what you need to do it...

Posted: Thu Oct 21, 2004 6:24 am
by William from NOLA
...I knew that... :banghead

I had more fun watching the voltage of my system though. heh