No problem - go for it!
I listen loud too, and requiring headphones is fine. If you tell me to play the file as loud as I can reasonably stand, I'm glad to do that. I'll cry foul
only if I have to turn up the volume even louder than that on a fade-out or reverb tail to hear the use of dither. Or if you record your flute so it never gets above -30 or some such. If you believe you can demonstrate the value of dither at loud but tolerable levels, please post it. Not just for me, but for everyone else here too.
--Ethan
Well, after trying it, I'm going to have to concede. I just can't play a wind instrument quietly enough (while still having appropriate levels for the loudest parts) to manage it. I switched to recorder as I was doing a bit better there, but I only managed about a 15dB range. There is no way that is going to do the job for such a test.
So instead, I tried to replicate my earlier test using a sine wave + pink noise acoustically. And I have to say I did a pretty good job on the reproduction. Even so, I couldn't find the quantization distortion! It should be there, but I can't generate it! And I tried pretty hard!
Have a look, this is the test signal, 1kHz at about -52dBFS, with 20dBA equivalent pink noise (the file I posted earlier, which apparently you couldn't read), in yellow. The quantization distortion peaks at 3, 5, 7kHz are pretty clear, and they are audible on cans too.
But the blue is the tail of me banging a single note (C6) on my piano. As you can see, its level is quite lower, -80dBFS. And it is still easily audible. Also, you can see I matched the test noise floor rather closely (this file was totally unprocessed). In theory, that should produce quantization distortion (although the level may have dropped too much at -80dBFS).
The peaks in blue you see are hum, and are consistent irrespective of source signal level. There is no measurable harmonic distortion above the noise floor. The peak of the note attack was -6dBFS. The microphone was
a KSM141 (on omni), a couple of feet from the spinet piano.
Thus I surmise that a sustain above -80dBFS must be required to measure quantization distortion. However, in this case, when the note had not faded to that level, but was around -60dBFS, its own overtones dominated any potential quant distortion. In fact, if you watch an FFT during the entire note decay, no differences can be detected between the original and truncated file. So not only would a sustained note at a somewhat higher level (but not too high!) be required, but it would also have to possess few overtones.
I have verified that proper truncation is occurring and no dither is applied on truncation by performing the same procedures on test signals, and measuring the resulting distortion.
This one is a mystery to me. I believe I should have been able to demonstrate some distortion, based on theory and practice with very similar test signals, but I cannot.