RE: So Tom, if that's the case. . .

Posted by Tony Lauck (A) on May 4, 2014 at 07:24:46

In Reply to: So Tom, if that's the case. . . posted by Chris from Lafayette on May 1, 2014 at 16:52:09:

The issue is whether or not the high frequency noise has been filtered out or not. When converting from DSD to PCM it is possible to filter out all of the high frequency noise and produce a clean looking spectrograph and some conversion software does this. However, this comes at the cost of steep filtering and this usually creates worse artifacts than the high frequency noise assuming one's analog amplifiers are suitably designed.

When DSD is converted to PCM there will be noise starting just above 25 kHz from the original modulator, creating this dilemma. If the source was one bit DSD at double speed this noise will be moved up the f-scale and filtering will be less critical. If multi-bit sigma delta modulation is used then the DSD noise will be reduced (6 dB per bit) and so will require less steep filtering.

Keep in mind that the only problem with the PCM format is its (generally) low sampling rate. It is this low sampling rate that creates the need for filtering on recording. Conversely, the only problem with DSD is the limited number of bits, creating a lot of high frequency noise that will be difficult to filter out, especially since the SACD standard for DSD was set by Sony and Philips at too low a sampling rate. They made the same mistake with SACD that they made with 44.1, namely setting the sampling rate based on technology in place at the time of their decision rather than optimizing the system for technology expected to arrive shortly, according to Moore's Law.

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

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Follow Ups Full Thread

Topic - BBC Interview on DSD - Robert J 02:59:32 04/30/14 (16)

RE: BBC Interview on DSD - vahe 04:48:50 05/01/14 (0)

Some people don't hear a difference . . - John PA 16:37:10 04/30/14 (13)

RE: Some people don't hear a difference . . - John Elison 18:15:25 04/30/14 (12)

so tired - mbnx01 11:35:59 05/01/14 (3)

RE: so tired - Tony Lauck 07:02:02 05/04/14 (0)

Well, the Norwegian did so today - E-Stat 20:02:59 05/02/14 (0)

RE: so tired - John Elison 13:02:29 05/01/14 (0)

RE: Some people don't hear a difference . . - AbeCollins 08:44:03 05/01/14 (7)

RE: Some people don't hear a difference . . - John Elison 09:37:37 05/01/14 (6)

PCM digital recorder - tailspn 13:37:12 05/01/14 (5)

So Tom, if that's the case. . . - Chris from Lafayette 16:52:09 05/01/14 (4)

RE: So Tom, if that's the case. . . - Tony Lauck 07:24:46 05/04/14 (3)

Yup - I see that and I agree - thanks, Tony! - Chris from Lafayette 09:26:13 05/04/14 (2)

RE: Yup - I see that and I agree - thanks, Tony! - tailspn 14:08:22 05/04/14 (1)

Thanks, Tom! [nt] - Chris from Lafayette 10:32:11 05/05/14 (0)

RE: BBC Interview on DSD - fantja 05:08:51 04/30/14 (0)

Follow Ups

RE: So Tom, if that's the case. . . - Tony Lauck 07:24:46 05/04/14 (3)

Yup - I see that and I agree - thanks, Tony! - Chris from Lafayette 09:26:13 05/04/14 (2)

RE: Yup - I see that and I agree - thanks, Tony! - tailspn 14:08:22 05/04/14 (1)

Thanks, Tom! [nt] - Chris from Lafayette 10:32:11 05/05/14 (0)

RE: So Tom, if that's the case. . .

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