rms wattage calculation?

[BoomBoxStereo 10+ year member]

is there a way to find out how many watts i am getting to each of my subs currently?

Click to read more...

 

[husker77 10+ year member]

I don't think so. You can have your amp clamped which will show you what it is capable of putting out. There are lots of vids on youtube on how to do that. The output of your amp is not constant it varies at different frequencies and volumes, so what it puts out with say a 50hz tone would not be the same as a 30hz tone at the same volume. When listening to music it varies a lot.

If I wrong someone correct me please, sometimes a wrong answer will bring a lot more replies than a question. ; )

 

[maylar 10+ year member]

There's no real way to measure RMS power with music. You can use a digital oscilloscope and get an average RMS voltage (if you know how) then do the math. Or measure the peak value and convert to RMS but that's not continuous.

 

[Flex68 10+ year member]

Agree with what Husker and Maylar said, but if you want to go to the trouble, you can get an idea...especially if you have access to an oldsillyscope. You can even get a very basic idea using a DMM and clamp.

What is your LPF set to , and what is the lowest your subs+box will hit?

Say that it is 80Hz and 30Hz, there you've got the range of freqs to test.

Clip your DMM leads onto speaker leads (or amp terminals) to obtain voltage measurements, and clamp your AC meter around the wires to get current measurements, with both set to "Range." Play your test tones at whatever intervals between 30-80Hz (or just choose the median freq of 55Hz) and take the readings from your meters.

Do the math (you can even plot out on a graph if you choose to check number of freqs/readings), and you can at least get a basic idea of what your subs are seeing...but one can never get any "exact" measurements on music.

And the first time you tweak your gains or adjust attenuation, its all out the window, lol