What then?
QSC sells professional equipment, for professionals, who can afford to hire lawyers to sue them. THD is measured on sine waves, with pure resistive load.
I do not understand your question.
They specified RMS power for long term output, and RMS power for peak output with certain level of distortions. Short term output means that the amp can supply such RMS power when distortions are not higher than specified percentage of THD. Long term output means that the amp can produce such RMS power for a long time without being damaged by heat.
Ignoring the subjective - as it's pointless as a target for more than one person - can you define what the "dynamic distortions" are, how to measure them? Similarly the "misbehaving" you refer to? If so, we are approaching a usable definition.
"W RMS" as already stated more than once was/is just a convention relating to the power rating of audio power amplifiers, simply to differentiate from deviations such as "W PMPO", etc.
If I look look through my old test literature and see that an amplifier under review/test delivered "33 W RMS" into a 4 ohm load and "101 W RMS" into an 8 ohm load, I know exactly what that entails. At the onset of clipping (typically the 1% THD point) the amplifier managed to deliver a continuous sinewave of 11.5V RMS in the 4 ohm case and 28.4V RMS in the 8.
Meaningless? Obviously not and I've never dealt with anyone who was/is professionally involved in audio engineering proper who was so clueless of the fundamentals so as to be unaware that "W RMS" is actually a technical misnomer.
If "W RMS" is too painful for you then just write "W", as many in fact do in defiance of convention and some old standards dictate anyway. Amazing to skim through over 10 pages of drivel over a situation which can be summarized in a single post.
If I look look through my old test literature and see that an amplifier under review/test delivered "33 W RMS" into a 4 ohm load and "101 W RMS" into an 8 ohm load, I know exactly what that entails. At the onset of clipping (typically the 1% THD point) the amplifier managed to deliver a continuous sinewave of 11.5V RMS in the 4 ohm case and 28.4V RMS in the 8.
Meaningless? Obviously not and I've never dealt with anyone who was/is professionally involved in audio engineering proper who was so clueless of the fundamentals so as to be unaware that "W RMS" is actually a technical misnomer.
If "W RMS" is too painful for you then just write "W", as many in fact do in defiance of convention and some old standards dictate anyway. Amazing to skim through over 10 pages of drivel over a situation which can be summarized in a single post.
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I was tempted to add "average" to my one-word post, but no one says an incandescent light bulb uses 100 watts average power, they just say 100 watts, and that's the amount of power it uses.
If you power a light bulb with a DC power supply and set the voltage so it gives the same brightness as when connected to an audio power amplifier, you can multiply the power supply's voltage output and current through the light bulb and get the power into the light bulb for the cases of both the power supply and the audio amplifier. (disregarding that the light bulb is not the exact 8 ohm resistive load we want to use on the amplifier) This was of course well known for many decades before the FTC published its ruling on "RMS power."
The FTC should have called it "light bulb power."
Oh yes there is. In fact under two different conditions
Look at the labels above each: one is "FTC Watts, 20Hz to 20 kHz, 0.1% distortion" which of course means Watts calculated measuring RMS Volts (what else?) into rated load, across all the stated band, meeting rated distortion value, and obviously meeting whatever extra condition FTC asks for (preconditioning, etc.)
Second set of values is labelled "EIA Watts" , same thing but at 1% distortion, which generally means "at the edge of clipping", and single frequency (probably 1kHz) , and maybe not under heavy preheating, in any case what the EIA rule asks for.
BOTH are "RMS Watts" in everyday parlance, just one set is stricter than the other.
Dynamically. I know crenellation of waveforms and spectrums with sound, and can predict what to minimize in amps depending on their topology. No, rather how to optimize the topology to make distortions less audible.
Sorry for spell-checker, I meant correlation!
Dynamic distortions are mostly caused by change of parameters of semiconductor devices with temperature, sag of power, shift of bias in output tubes, etc... It is what we use subconsciously to recognize reproduction of sounds, because we expect to hear sounds in their dynamics.
Take, for example, spectrum of grand piano, and apply some different envelope, like soft attack, long sustain, and fast decay, and you will never recognize the instrument.
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