Common usage - opinion - defines what words mean, not "facts".
I think this writer does not know his mathematics.Let us assume a sine wave input signal. The way the amplifier power is measured is to use a nominated load, and then to wind up the volume control until the output is just below the point at which it begins to distort significantly (according to some agreed and stated distortion measure, though this is not critical in practice). The average output power over many sine wave cycles is then measured. This is defined as the time integral of the instantaneous power over the measured time, divided by that time (which is always taken to be very large).
In simpler words, it is a straight average or mean of the output power, measured over a long time, and has a real technical significance (e.g. it measures the heating power of the amplifier).
By contrast, RMS (root mean square) power, would have to be defined as the square root of the time average of the square of the instantaneous power, since this is what 'RMS' means. This could be done, but it is not the power as measured, and furthermore, it would have no technical significance (e.g. it doesn't measure heating power).
© 2003 by Stephen Dawson
Are you just trolling? The RMS power of a sine wave is 1.225 times the average power of a sine wave. Do the math.I think this writer does not know his mathematics.
Average power and RMS power of a sine wave are mathematically identical.
Show me your math.Are you just trolling? The RMS power of a sine wave is 1.225 times the average power of a sine wave. Do the math.
V = sin(t)Show me your math.
Sure.Do you know how to do integrals?
We're talking about power, not voltage.My math tells me that the RMS value of a 1V sine wave is 0.707V.
No. RMS power = RMS(P(t)) (which is not a useful number)I see the confusion.
rms power = Vrms^2/R
not rms of (V^2/R)
Then this thread will probably run and run, in ever decreasing circles, until it disappears up its own...Common usage - opinion - defines what words mean, not "facts".
Nah, they understand: "The result is that the average or mean value of a symmetrical alternating quantity is zero because the area above the horizontal axis (the positive half cycle) is the same as the area below the axis (the negative half cycle) and cancel each other out in the sum of the two areas as a negative cancels a positive producing zero average voltage."This site also doesn't know how to figure out the (lack of) difference between RMS and average.
http://www.electronics-tutorials.ws/accircuits/average-voltage.html
Well if they're literally using RMS power and not average power, then they're inflating their specs by 22%, but I doubt their marketing departments would be happy with that; it's too small of an exaggeration.Here are some of the nobodies that use RMS watts for their ratings:
Well, you can say "average power = 100 W" and "peak power = 200 W". Those are meaningful and correct. But yes, the units are just "watts"...does not allow for any reference to 'RMS Watts' - 'peak power Watts' - 'music Watts' - 'average Watts' -- or indeed any further qualification of the 'Watt' at all.....
The most common use of the phrase would seem to be '100W RMS' or '200W RMS'..etc.... There have been (and continue to be) literally thousands of such examples quoted in audio amplifier specifications over the years.Well, you can say "average power = 100 W" and "peak power = 200 W". Those are meaningful and correct. But yes, the units are just "watts".
by Jake Hertz
by Jake Hertz