Not sure about that...mqi looks pretty much like rent seeking and anticompetitive practices as it only makes things worse signal wise than what's already available.
🙂
I think it dates from long time before: "Panem and circenses". (Panem for the few ones, circenses for all the others).
And the ancient Greeks had a proverb: When it smell and taste like snake oil, when it has the color of snake oil, it's not good for your gearbox.
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You guys worry far too much about potential rip-offs, when you should be listening for improvements in sound quality when audio reproduction is the goal, not just bad-mouthing someone's attempt to make a 'different' audio product.
Measurements are fine, BUT they do not ALWAYS tell us what an audio component will actually sound like in comparison to its competition. I know this because I, too, fell for believing that in designing certain products, and measuring them myself to my satisfaction, would inevitably make an excellent or at least passable sounding product. It was NOT SO on at least two occasions that I fell into at Parasound. It took extensive re-work of two power amps that I designed to make them acceptable sounding with professionals, even though they measured just fine. I just had a third power amp fail to deliver, but this time it was in the measurements, rather than in subjective listening (that comes later) and I had to reject it. This time is was the inability of the amplifier to drive 4 ohm loads well enough. 8 ohms was OK. We had to increase the number of output transistors to make it work right, but that was the not the original problem with the first two amps that did not work out optimally. Now how did I determine that these first amps were 'compromised'? I couldn't measure anything obvious, but I depended on independent listening feedback from audio professionals who would be honest with me.
On the other hand, I have HEARD tube based audio systems that measured really lousy, sound good! In fact, the best sound at a particular audio show. Therefore, rejecting something out of hand, just because it has lousy measurements, is not always the answer either.
Often, global negative feedback causes some real changes in the NATURE of the sound quality, often to its detriment, so sometimes good measurements, might cover up what is intrinsically wrong with the audio product. Oh well, I'll just keep 'buggering on'. Like Winston Churchill did in WW2. '-)
Measurements are fine, BUT they do not ALWAYS tell us what an audio component will actually sound like in comparison to its competition. I know this because I, too, fell for believing that in designing certain products, and measuring them myself to my satisfaction, would inevitably make an excellent or at least passable sounding product. It was NOT SO on at least two occasions that I fell into at Parasound. It took extensive re-work of two power amps that I designed to make them acceptable sounding with professionals, even though they measured just fine. I just had a third power amp fail to deliver, but this time it was in the measurements, rather than in subjective listening (that comes later) and I had to reject it. This time is was the inability of the amplifier to drive 4 ohm loads well enough. 8 ohms was OK. We had to increase the number of output transistors to make it work right, but that was the not the original problem with the first two amps that did not work out optimally. Now how did I determine that these first amps were 'compromised'? I couldn't measure anything obvious, but I depended on independent listening feedback from audio professionals who would be honest with me.
On the other hand, I have HEARD tube based audio systems that measured really lousy, sound good! In fact, the best sound at a particular audio show. Therefore, rejecting something out of hand, just because it has lousy measurements, is not always the answer either.
Often, global negative feedback causes some real changes in the NATURE of the sound quality, often to its detriment, so sometimes good measurements, might cover up what is intrinsically wrong with the audio product. Oh well, I'll just keep 'buggering on'. Like Winston Churchill did in WW2. '-)
Do you think these things will always be unmeasurable? Is anyone interested in even finding out if they could be or would that defeat the object?
Hopefully no, yes, and no, since design would rather not be blind.
But the question was raised for JC to answer.
Not exclusively for him. There seems to be more acceptance recently that the traditional measurements aren't adequate and yet the desire to find better ones isn't as evident as the pleasure taken in the mystery.
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If you mean that there are things we will never understand? Welcome to the human condition. 🙂
I think it's more a skill in deciphering the spectrum of the output, or from the residuals of a distortion analyzer. The answers are there.
-Chris
-Chris
Of course, we try to measure what the problems are, as we have for multiple decades. However, our test equipment is LIMITED to just continuous sine waves, and can't completely represent the challenge of real music that changes in level constantly and instantly on occasion, as well as containing a number of mathematically related sine waves simultaneously appearing together. We have no way, at this time, of accurately (enough) making a measurement of all the differences that probably occur.
Try, just try, to develop asymmetrical waveform testing. Both with either + and/or with - average in waveforms. Compare with sine waves.
Check for dc offset shift, bias shift and distortion differences.
THx-RNMarsh
Check for dc offset shift, bias shift and distortion differences.
THx-RNMarsh
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Richard is right. Asymmetrical waveform sources, even if continuous, show problems that most test equipment will not directly measure.
This is crap and always has been, you guys just decided to not learn any signal processing basics and BS your way on and on.
YouTube
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This was the last page of an IEEE paper that I did in the 1970's. I gave the paper in Tulsa first, and a modified version in Tokyo, Japan in 1978, and then a third version for the AES in San Francisco and in 'Audio' magazine in 1979. The second paper that I am putting up here for completeness was about 5 years later, and uses an asymmetrical test waveform to test for DA in capacitors.
A third paper by Dr Hirata of Japan in about 1980, also used an asymmetrical waveform to show 'hidden' distortions brought out by asymmetrical signals. That is a separate paper that I will not put up in this response, but is equally valuable.
A third paper by Dr Hirata of Japan in about 1980, also used an asymmetrical waveform to show 'hidden' distortions brought out by asymmetrical signals. That is a separate paper that I will not put up in this response, but is equally valuable.
No it isnt crap. You just think of it in a certain fixed view. Like you do with polar caps for coupling .... ignoring the real practical effects - such as, dc leakage affects on circuit over time and temp. Leakage and esr and C changes over time and frequency have effects not seen in THD test but can materially affect the sound and have detectable differences from a film which is more stable and less problematic. The THD test doesnt care if esr is high or low. Or what the C value is. and the effects on circuit with dc leakage etc.
If you test with asymet signal... you can see undesired, practical circuit effects/behaviour in some actual designs. Just try it. None of this -> it can all be broken down to sinewaves stuff, either. Which it could but, you wont find some of the actual circuit misbehavior. Of course, when you find it, you can design it out.
Just an old suggestion.
Like JC says.... It works for me, so i use it.
THx-RNMarsh
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