RMS and PMPO

[Normanfernandez]

Can someone please help to calculate, RMS to PMPO
And PMPO to Rms
Thank you so much!
Regards Norman!

[Misu]

Hi,

Both <standards> are more or less lies.
The big one is PMPO, my advice: ignore or look to the speakers power.
RMS, if is true, it is OK but for example for 2 way speaker if subwoofer have 150W and twitter 50W most of company write 200W RMS and is not true.
Let's take an Yamaha example: PSR S970 have 2x15W RMS = 30W
If you look on the power consumption you will see 20W this means that they take 20W from somewhere and with keyboard produce more 10W. Impossible. 
So, if the power consumption is 20W with a very good efficiency (90% - I don't know if it is possible) the audio RMS power can be 2x9W.

I hope it will be useful to you,
Regards
Mihai

[mcbrown]

I prefer to go by the dB SPL when judging if a speaker will meet my power requirements.

Murray

[Normanfernandez]

How do I convert
RMS to PMPO ??
That's what I'm trying to do

[Misu]

Hi again,

You can't make a real conversion.
Usual RMS you can calculate like this:
Put an sinus oscillator 1 volt 1000Hz at the IN of power amplifier, rotate volume knob to max. until you still have sinus to OUT and measure maximum Volts and Amps
Ex if you have 50 Volts and 10 Amps -> RMS=500W
Regarding PMPO I have on my computer 3 way speakers 600W PMPO write on the box, reality is I don't know if I have 10W RMS.

Good luck!
Mihai

[mcbrown]

https://www.edaboard.com/showthread.php?t=178106&s=bb060f0dcf8259ed05f60b7ae5612d57

It seems to be a bit of a guessing game at best for doing these calculations. Realistically whether they be RMS or PMPO it is only the manufacturers values that were calculated using whatever method they see as making their product competitive in the market place when buyers compare their product to another. Who can you trust to give the actual correct output values.

I would not even bother to look at PMPO as the numbers are so unrealistic but would go by RMS and more so the dB SPL (sound pressure level).

Murray

[Normanfernandez]

Thank you so much!
I'll have to keep reading stuff
Till I come close to completely understanding
Regards Norman!

[travlin-easy]

Though not 100 percent on the money, the easiest way is to use OHM's law and look at the power consumption specs, volts, amps, then calculate the wattage. A lot of amp manufacturers like to hype their wattage, however, they often do not reveal whether it's RMS or Peak power. The Roland Cubes are a classic example. Them claim 30 watts, but in reality, those amps only consume 4 watts.

All the best,

Gary