Measuring amplifier wattage?

[Slaugh 10+ year member]

hi i was thinking about connecting a 4ohms resistance to the bridge output of my amplifier... doing so can i just use a DMM to measure it's voltage and find the wattage my amp can produce?

what are the formulas again to calculate wattage?

and just something else i want to do, is to set the **** gains of my system correctly using the DMM, how can i do it the best way? i know the preouts of my hu is rated at 10k ohms, where the hell can i find such resistance? or is that just not the way it works lol?

waiting for the answer heh

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[Slaugh 10+ year member]

hmm i dont know if i needed any resistance to measure preouts output but i just removed em off the amplifier and put the DMM to measure it's ~voltage with a sine wave of 60hz and on volume max, bass +5, MX on, subout max i got 3.7volts on the preouts, so is that how alpine measures it's preouts? to work at full volume, bass +5, subw out max and MX on?

 

[AznRevlAzn 10+ year member]

google is your best friend

(ACV/OHMload)^2 = wattage

to set your gains use SQRT(RMSwattage*OHMload)

 

[Slaugh 10+ year member]

google is your best friend

(ACV/OHMload)^2 = wattage

to set your gains use SQRT(RMSwattage*OHMload)

thanks but i dont get it, why did you edit the first formula, it was at first ACV^2/Ohmload and it was working, but now it seems to give me straneg results, why did you edit it?

and what is SQRT? no idea what this is at all lol

 

[XtrmAudioCncpts 10+ year member]

http://forum.soundillusions.net/showthread.php?t=55924

this may help it may not

 

[AznRevlAzn 10+ year member]

thanks but i dont get it, why did you edit the first formula, it was at first ACV^2/Ohmload and it was working, but now it seems to give me straneg results, why did you edit it?
and what is SQRT? no idea what this is at all lol

i had it wrong the first time, i am dosing off and falling asleep at my UC computer lab, it's so bad.... never get a night job my friend, ever...

also if you were to go by the previous one i typed in, if you had a load of 2ohm or 4 ohm you'd clip the amp and most likey kill the sub in seconds.

 

[skadude016 5,000+ posts]

square root

 

[Chevyaudio 5,000+ posts]

hi i was thinking about connecting a 4ohms resistance to the bridge output of my amplifier... doing so can i just use a DMM to measure it's voltage and find the wattage my amp can produce?
what are the formulas again to calculate wattage?

and just something else i want to do, is to set the **** gains of my system correctly using the DMM, how can i do it the best way? i know the preouts of my hu is rated at 10k ohms, where the hell can i find such resistance? or is that just not the way it works lol?

waiting for the answer heh

I believe to measure the Output in wattage you have to have a Clamp Meter style DMM. that way your can measure the current draw.

 

[Slaugh 10+ year member]

i had it wrong the first time, i am dosing off and falling asleep at my UC computer lab, it's so bad.... never get a night job my friend, ever...
also if you were to go by the previous one i typed in, if you had a load of 2ohm or 4 ohm you'd clip the amp and most likey kill the sub in seconds.

but i used this site to compare the results: http://www.riedon.com/riedon_calculator.htm

and it seemed to be working perfectly using the first rule, but the second one doesnt work //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

48.98²/4=600

how so then?

 

[AznRevlAzn 10+ year member]

I believe to measure the Output in wattage you have to have a Clamp Meter style DMM. that way your can measure the current draw.

or he can have a needle style and just insert them into the speaker outs //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[AznRevlAzn 10+ year member]

oh wow, so i was right before i edited the first formula lol.

 

[Slaugh 10+ year member]

so i put the DMM into the bridge of my amp, that's where my subwoofer is and started watching the voltages rise...

playing a 15hz sinewave, the best i could go safetly because of the **** 50A max power supply was this

i think i've never seen my sub excursing so **** much... how can i do this without a subwoofer? i thought the **** thing was gonna die or something... can i just buy a 4ohm resistance or something lol?

thanks

 

[Slaugh 10+ year member]

hmmm any help lol