To put some ballpark numbers on it, my experiences indicate that a 100% competent 60W amplifier driving average sensitivity, 90dB speakers is sufficient for domestic listening - with the right source material, this combination will give you shouting at the top of your voice to be heard SPLs, and get your ears ringing within 5 minutes, quite enough I would suggest ... 
never said that , so go ahead and quote me , should be easy ...
ok
Have you measured or is this Wikipedia....
Again you say loud , i said domestic , have you ever measured how much power is required to raise VC TEMP to 150, i have measured while testing and have never seen such temps
lol, yes over voltage , who would have thunk it ...
Dont be so hard on yourself, feel free to show how you arrived at 150C, i know it's easier for you to deflect..
...
Any of those ring a bell?
No, not PA disco use, but undoubtedly a loud house party.
I understood what you meant to say, but I also read what you actually wrote. You were very clear that 150C VC temp was not possible in a "domestic" setting, because that's what your measurements told you. Apparently when you do the measuring, measurement trumps experience and theory, while when others do the measurements, your experience trumps the measurements.
But that's OK Wayne, I really like watching the dance.
That happens A LOT, and not only here, either.
I don't believe in magic or voodoo, but I cannot be in denial about something that is theoretically not possible when it's happening right in front of my eyes, and repeatedly.
As an example, my wife hates computers, and they hate her back. I have seen her do things which are not supposed to be able to be done, in fact which blatantly contradict the user manual's claims. Things which I later tried to replicate, but never could. And on more than one occasion. How and why - frankly, I wish I knew, but I haven't the foggiest of ideas.
Not to even mention the situations when the math says that should be a 4k7 resistor, and the damn thing won't work, but if I change that to say 7k5, it works like a charm, when theoretically it should be gasping and struggling for current.
seems difficult, to think of, '3', as many.
50, maybe ...
--
still have my copy(s).
possibly the most interesting, and useful article,
this poster has encountered thus far,
about audio equipment.
i'd like to convey my thanks, to you, and Mr. Jung.
that article has made a huge difference.
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I have tried a real life test. Input signal is 1st 100%, 2nd 70% and 4th 70% (relative amplitudes). Two cases, all harmonics in phase (phase shift 0 deg) and second case is 1st harmonic with 45° phase shift. The second one results in asymmetric wave.
Results attached, first for 0° phase shift, symmetric wave.
Attachments
Asymmetric wave, phase shift 45°. Please note that amplitude spectra of symmetric and asymmetric waves are identical (input signal spectra). We can see some differences in spectra at amplifier output, due to different amplitude stress and amplifier nonlinearity.
Attachments
Frenchie ,
JBL :
600 W AES continuous pink noise
Sensitivity: 97 dB SPL, 1 W, 1 m (3.3 ft)
Frequency Range
: 30 Hz - 2.5 kHz
Power Compression:
at –10 dB power (60 W): 0.7 dB***
at –3 dB power (300 W): 2.5 dB
at rated power (600 W): 4.0 dB
@ 60 watt power compression on their bass unit is .7db, consistent with what we found 20 yrs ago, when testing RMS below 32 watts and consistent also when used in typical domestic hi-fi, VCID would not be an issue.
60 watts RMS would translate to over 720 watts peak power when used in domestic hi-fi situation. even you head banging nutters couldn't go there ..
Thank you for proving my point.
If all this compression were due to thermal resistance increase, this would correspond to VC temperatures of 43, 197 and 387 degrees K above ambient. Obviously, their are mechanical non-linearities in the suspension which also produce compression, but it gives you a sense of the numbers.
Now, with this example, you used a professional JBL driver that can handle 600 Watts continous noise power. Typical drivers in living room speakers will handle less than 60 Watts noise power. 30 Watts is even optimistic for most.
About your 'test' I vented some doubts earlier (posted at #56027). How can you go from 1 to 16 Watts without an increase in distortion or impedance? All drivers have increasing distortion with increasing power. You should have seen impedance increase as well. It looks like you pulled these results out of your brown star.
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Just tried. No thermal components, with signals down to 10Hz. With signals down to 1Hz FFT resolution is insufficient.
Pavel, I spent some time years ago with this asymmetric signal stuff and could not get through to anyone involved. The question is topology signature or just bad design signature, IMHO positive results were obtained when full power bandwidth was reached/exceeded (old news). This should rest with testing the uA741 for audio.
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A.wayne,
Could you tell us how you did those thermal temperature measurements with an infra-red device. Was the dust cap removed to see the gap temps? What about a time factor in those measurements? I would love to believe that I could just forget about the temperature rise it would mean I could just use the lowest curie point magnets and forget about demagnetization. Motor mass will definitely affect the results over time and the maximum temp reached but in a small consumer motor you will also have much less mass to absorb any heat to dissipate. One factor we have to look at is the diaphragm area and excursion needed to produce a certain sound pressure level, it won't take much with a 15" cone in a house to get really loud but a smaller 6" or 8" speaker is going to have to work much harder to reach those same sound levels and much more input power to the voicecoil. We also have to consider voicecoil diameter in all this.
I don't want to get into an argument about this, I really want to understand under what conditions your measurement were made.
Could you tell us how you did those thermal temperature measurements with an infra-red device. Was the dust cap removed to see the gap temps? What about a time factor in those measurements? I would love to believe that I could just forget about the temperature rise it would mean I could just use the lowest curie point magnets and forget about demagnetization. Motor mass will definitely affect the results over time and the maximum temp reached but in a small consumer motor you will also have much less mass to absorb any heat to dissipate. One factor we have to look at is the diaphragm area and excursion needed to produce a certain sound pressure level, it won't take much with a 15" cone in a house to get really loud but a smaller 6" or 8" speaker is going to have to work much harder to reach those same sound levels and much more input power to the voicecoil. We also have to consider voicecoil diameter in all this.
I don't want to get into an argument about this, I really want to understand under what conditions your measurement were made.
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