how to measure watts

[TrlcKed_OuT 10+ year member]

ok i know what u would use to find volts but what do i need to do or have to measure the amount of watts an amp is pushing???

Click to read more...

 

[JimJ 5,000+ posts]

To do it right?

a stable dummy load that has a constant impedance, a stable bench power supply at a known voltage, and an o'scope to make sure the waveform isn't clipping.

In a pinch, you can get by with Ohm's Law and a voltmeter. Check the gains-setting thread to learn how to do this.

 

[iamamp3pimp 5,000+ posts]

i have a voltmeter

 

[Nikuk 5,000+ posts]

clamp meter & VOM. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[squeak9798 5,000+ posts]

Without the proper equipment like Jack mentioned, you aren't going to get anywhere close to an accurate measurement.

 

[noob with an RS 10+ year member]

AMPERAGE TIMES VOLTAGE EQUALS WATTAGE. (amps x volts = watts)

but i don't know how to measure that myself.. my guess would be hook up an ammeter to your alternator.. then find out how many volts is coming out your amp with a scope or DMM.. then multiply the two figures together?? i dunno i never took the initiative of trying since my alt. is hard to reach and i dont have an ammeter to begin with, nor the experience in using one. but i do now current times voltage equals watts.. i learned that in A6 electrical //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif

 

[saywhat? 5,000+ posts]

a ruler

 

[g30ffr3y 10+ year member]

i have a multimeter setup right near my HU... im always

watching my voltages...

makes for the safest bumping at the highest levels my setup can

handle...

 

[tRiGgEr 5,000+ posts]

Remember that the concept of power is basic. AC Volts squared divided by

the impedance. Pretty simple. Some will say “Hey, that’s not how they measure amplifiers. They hook them up to load resistors and run sinewave..not music.!” I don't know about you guys, BUT...do you listen to load resistors? I sure as Hell don’t listen to load resistors or sinewaves. Therefore what is important to me is reality. What is my amplifier making into my speakers?

To do that is simple. Get a Digital Volt Ohm Meter (DVM/DMM). Set it to AC volts and touch the DVM leads to the speaker terminal of the amplifer. Crank the system for all it’s got! Read the biggest number you see.

So... lets say you get 33 AC volts out as the biggest number. You have 2 - 4 ohm 12 inch woofers paralleled (2 ohms).

33 X 33 = 1089 = 544.5 watts Peak

2 2

Now this is peak power"musical peak power". Which is the most important to me. Because I listen to music. But if you want to know ”Continuous Power” take the number you got (544.5 Watts in this particular case) times .707 which is RMS (root means square) and that will equal continuous “RMS” power .

544.5 X .707 =384.96 watts RMS

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[squeak9798 5,000+ posts]

^^ Nice copy-paste from the Concept website //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Anyways, in reference to that article;

1) That article doesn't take into account that fact that the amplifier could (and would likely be) clipping, given their instructions to "crank the system" (which, to most will mean turn the gain/bass boost up as high as it will go).

2) Doing that type of measurement will give you some sort of power figure, sure. Doesn't mean it's accurate as to how much power the amplifier is actually capable of cleanly producing //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif So, now you'll have thousands of 16 yr olds running onto the forums going "OMGWTFBBQ!!! My amplifier is overrated! Grab your pitchforks, lets all take down Kicker for lying to us!!"

 

[nauc 10+ year member]

p=(v*v)/ohms

 

[tRiGgEr 5,000+ posts]

^^ Nice copy-paste from the Concept website //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Anyways, in reference to that article;

1) That article doesn't take into account that fact that the amplifier could (and would likely be) clipping, given their instructions to "crank the system" (which, to most will mean turn the gain/bass boost up as high as it will go).

2) Doing that type of measurement will give you some sort of power figure, sure. Doesn't mean it's accurate as to how much power the amplifier is actually capable of cleanly producing //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif So, now you'll have thousands of 16 yr olds running onto the forums going "OMGWTFBBQ!!! My amplifier is overrated! Grab your pitchforks, lets all take down Kicker for lying to us!!"

Actually I have the PDF article.

1.) correct. But if you test it after setting the gains you should be fine.

2.) Entirely correct.