|
Digital Drive Upsamplers, DACs, jitter, shakes and analogue withdrawals, this is it. |
|
|
|
Digital Drive Upsamplers, DACs, jitter, shakes and analogue withdrawals, this is it. |
|
In Reply to: Nyquist Theorem is valid posted by Feanor on November 19, 2015 at 05:41:44:
"That is, you only need to sample at twice the frequency you intend to reproduce to capture that frequency perfectly. And very, very few, mostly very, very young people can hear 20kHz much less higher. Thus the adequacy of the 44.1kHz Redbook standard."
Maybe in theory, but a lot of us can hear the time domain distortions at HF, even if it's below 20 kHz.... If we couldn't, there wouldn't be a large group of people who believe no filtering (non-oversampling or "NOS") was the best approach to CD playback. I prefer "short" filters personally.... Which don't adhere to Nyquist as well as "long" filters, but I prefer how they sound.
"However the trick part, I would surmise, has always been the filtering of frequencies above the maximum target frequency, (22kHz for Redbook), that are just noise. The advantage of high resolution is in this realm, i.e. it is easier to design filters with fewer artifacts, (such as phase shift or ringing), when the digital frequencies are higher to begin with."
If the sample rate is high enough, I think all filtering could be analog, which would significantly simply the process.....
"I might suggest, as a non-expert, that advances in DAC design are almost entirely a matter of filtering with fewer artifacts. BTW, I'm extremely pleased with my Schiit Bifrost Multibit with its 'closed form' filtering; the level of realism is astonishing, at least at that price point."
At the 44.1 kHz sample rate, there is no filter that is "good enough" to where it would be indistinguishable from 15 ips analog tape.... The filters have advanced to where the obtrusiveness at HF has become tolerable in a lot of cases. But still not completely transparent. (Vinyl tells me this whenever I listen to it.) Schiit is one of the better recent products.
Had the CD been sampled at 48 kHz, we may not have had half the problems we've been having.... The Nyquist frequency would have been high enough (24 kHz vs. 22.05 kHz) where the HF artifacts could have been significantly lower.
The high-rez movement was based on the notion that the resolution of 16/44 Redbook CD wasn't sufficient for true high-fidelity audio playback. I agree with that notion personally, but I've yet to experience a high-resolution digital format that I prefer over CD.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: Nyquist Theorem is valid - Todd Krieger 13:48:17 11/21/15 (1)
- Reply to Todd Krieger - Feanor 05:21:39 11/22/15 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
