RMS Power?


I often see power specifications like "100W RMS".  There is no such thing as RMS power.  Of course, you can calculate RMS value from any curve, including power curve, but it won't represent anything.  "Real" power representing heat dissipated in resistive load is "Average Power"   Pavg=Vrms*Irms.   In case of sinewaves Pavg=0.707Vpeak * 0.707Ipeak = 0.5Ppeak,  or Ppeak = 2Pavg. 

Term "RMS Power" or "watts RMS" is a mistake, very common in audio.
128x128kijanki

Showing 4 responses by williewonka

Here’s what Wiki thinks (it’s very long)
https://en.wikipedia.org/wiki/Talk%3AAudio_power

One line in the text ...
For most, just comparing the RMS power number is useful

I guess to some - But it’s been a while since I paid any attention to the RMS numbers on amps or speakers - I go to the store and audition. You can quickly tell if the amp has enough oooomph (or not)

I really think there are a lot more "pressing things" to get this worked up about - world peace, climate change, famine, disease, etc......

After all it’s just a number!
- It’s used by many in the audio business as " the norm"

And y’ain’t gonna change that any time soon!

If I remember correctly there was a moment a few years back, when some companies used Peak or Continuous power ratings, but it appears that things have reverted back to good old RMS!

But I would like to thank Kijanki for letting us know "watts" what
- or is that whats "Watt" :-)

Hmmm - I think I’ll elect to - NOT loose any sleep over it.

Just sayin !


@kijanki -

Wliliewonka - It is "watt" and not "Watt" (units start with small letter - but I’m sure you don’t care). You can go back to sleep now.

Peace - I really have no quarrel with you.

Might I suggest that since you have so eloquently demonstrated the incorrect use of the term - that you try contacting at least one of the offending manufacturers and ask them why they still elect to use this invalid term.

"We" might all agree that it is incorrect. But it does no good to preach to the choir.

Perhaps some feedback from the industry could shed some light as to why they continue this practice?

Without it, the reasoning behind it's continued use is just conjecture.

Regards... 
Umm, it’s “lose”, not “loose”. Uggghhhh!

@sleepwalker65 - sorry about that.

Simply "typo" that I missed - it can happen to anyone - at some point

Happy Listening :-)