Some audiophiles and companies like Sony argue that high resolution audio matters while others argue that those are indistinguishable. These arguments can only be proven by statistics on blind tests. Some tests suggests that some people seems indeed distinguishes high resolution sources. Audio experts says that this is because the mixing and mastering target between CD sources and hi-res sources are different; they made to sound differently in the first place. I do personally believe the utility of the high resolution audio not only for mixing purpose but also for listening purpose. (For processing audio, hi-res definitely helps to reduce distortion. Digital filters is distorted heavily near the Nyquist frequency.) But I am not arguing that we can hear beyond 24kHz. ( Indeed some people can hear 24kHz but no beyond.) I am arguing that we need infinitely high digital sampling rate to reproduce 20Hz-24kHz analog signal.
Think about 24kHz signal in 48kHz sampling. If the phase is shifted pi/2, the signal is shown as 0. The digital sampling with frequency in the last octave under the Nyquist frequency only has peak samples, so there is almost zero reproducibility concerning phase shift. Even if the frequency of the signal is not a divisor of the sampling frequency, ghost beating sound is produced. So, in CD Sound, 10-20kHz sound is not well reproduced and has no meaning unless it is harmonics of another lower sounds.
2nd last octave sound under the Nyquist has a sample middle of the curve, so at least we can guarantee that 1/sqrt(2) of the amplitude of the original sound can be reproduced. (Or, maybe we can expect better by physical low-pass filter.) So on for the higher…
What I really recommend is to play 24/192 or at least 24/96 with 20khz lp filter.
So, I suggest an experiment to compare not only between different sources on the same player, but also between different lp filter but using the same hi-res source and the same DAC. If my theory is right, Sony’s hi-res capability issue of speakers are useless, but hi-res for DAC is important.
I have no professional background on this, so I dont know whether people already know this. I think my story makes sense physically, so most specialists maybe already know this.
But the reason I am raising this as problem is that I dont understand why Sony counts speaker’s reproducibility of 40khz signal. I know that there is meaning to have flatter FR in audible frequencies generally when we demand hi-res capability of analog device. But is there more meaning over that?
http://archimago.blogspot.com/2016/07/musings-digital-interpolation-filters.html
https://en.wikipedia.org/wiki/Bilinear_transform
