Shadorne, thanks for your above post, gotta love objective measurement.
The threshold of audibility for pure tones was found to be about 10 ns rms at 20 kHz and higher at lower frequencies.
I would like to seek your opinions on the above, though.
1. I am gong to assume that Dolby typically has experienced (read, greybeards;)) and to listen for audibility at 20kHz and on a pure test tone, would seem to be counterintuitive. Firstly, high frequency hearing goes down with age and you really have to crank a 20kHz tone up, to hear it, were they trying to perform a "worst case" secenario? But the above makes sense as they do say it is higher at lower frequencies.
2. Secondly, why do it with a pure test tone, when we react to complex waveforms in another manner, and music is, of course made of complex waveforms so I am surprised they didn't use a beat frequency oscillator or any other complex waveform. Do you have input on that?
3. If the threshold of audibility was indeed higher at lower frequency, why not take most of the tests at 1kHz, right in the middle of the curve?
Not attacking you nor their tests at all. I have been an executive for so long, and off the test bench, that I am just curious if you knew?
Now, unless I am missing something, when I look at Atkinson's Miller Suite data,it seems about 250pS PEAK is where he draws the line on good/bad DAC performance, which means, if I am understanding this correctly, that virtually any audiophile DAC is an 100X better approximately than what they say is the hearing threshold..Yes? No?
Thanks,
C
The threshold of audibility for pure tones was found to be about 10 ns rms at 20 kHz and higher at lower frequencies.
I would like to seek your opinions on the above, though.
1. I am gong to assume that Dolby typically has experienced (read, greybeards;)) and to listen for audibility at 20kHz and on a pure test tone, would seem to be counterintuitive. Firstly, high frequency hearing goes down with age and you really have to crank a 20kHz tone up, to hear it, were they trying to perform a "worst case" secenario? But the above makes sense as they do say it is higher at lower frequencies.
2. Secondly, why do it with a pure test tone, when we react to complex waveforms in another manner, and music is, of course made of complex waveforms so I am surprised they didn't use a beat frequency oscillator or any other complex waveform. Do you have input on that?
3. If the threshold of audibility was indeed higher at lower frequency, why not take most of the tests at 1kHz, right in the middle of the curve?
Not attacking you nor their tests at all. I have been an executive for so long, and off the test bench, that I am just curious if you knew?
Now, unless I am missing something, when I look at Atkinson's Miller Suite data,it seems about 250pS PEAK is where he draws the line on good/bad DAC performance, which means, if I am understanding this correctly, that virtually any audiophile DAC is an 100X better approximately than what they say is the hearing threshold..Yes? No?
Thanks,
C