DSD Battle Royale!
- Thread starter Bruce B
- Start date
Agree- thanks to all, especially (for me) Tom.
This subject, complicated as it is, reminds me of a famous occasion when F E Smith ( a learned barrister in the 1920s and later Lord Birkenhead- and I believe Lord Chancellor), who was known for his learned loquaciousness, finished a long-winded and complicated submission to the judge. The judge, somewhat bored and confused, said: "That's all very well, Mr Smith, but having listened to you for 30 minutes I'm none the wiser." "That may be so, mi'lud" said F E Smith, "but you are considerably better informed!"
Like the judge, I feel better informed but not a lot wiser!
Philip
This subject, complicated as it is, reminds me of a famous occasion when F E Smith ( a learned barrister in the 1920s and later Lord Birkenhead- and I believe Lord Chancellor), who was known for his learned loquaciousness, finished a long-winded and complicated submission to the judge. The judge, somewhat bored and confused, said: "That's all very well, Mr Smith, but having listened to you for 30 minutes I'm none the wiser." "That may be so, mi'lud" said F E Smith, "but you are considerably better informed!"
Like the judge, I feel better informed but not a lot wiser!
Philip
Both PDM and PCM are ways to depict an analog waveform in a binary coded form. It's like writing down a recipe for lasagne in both Spanish and German, and arguing that italian is more "natural" because Spain is closer to Italy
Julf,
Well, I thought I was understanding this nice exchange of DSD-PCM posts, but after reading this analogy I am not so sure anymore.
Spain is not even closer to Italy than Germany
Pulse density modulation is just that, modulation - a way to convey a signal (in this case analog) over a different media (in this case digital). You have converted an analog signal into digital (how else could you transmit it over a network or store it on a hard disk?) and back into analog. It is just that in PDM most of the hard work is done at the analog-to-digital stage, and less of it in the digital-to-analog.
Both PDM and PCM are encoding/modulation methods. One is easier to convert into analog, the other is easier to process.
So if PWD is ENCODED, why can we get music when we connect the stream directly to a speaker? That is what I keep going back to. Cant get away from that.
Witness an analogy being stretched to snapping point...
Hahaha
You should have said: Culturally man, culturally!
LoL
Just because I can hear my radio amateur neighbour's transmissions in my heating radiator doesn't mean radio waves are the same as mechanical vibrations.
Amplitude modulated radio waves can be heard (if strong enough) using any non-linear device. AM is still a form of modulation/encoding. PDM can be heard using any averaging/low-pass-filtering mechanism. It is still a form of modulation/encoding. More relevantly, it is a form of *digital* encoding that can only take dsicrete values, and has a finite resolution.
It is fair to say IMO at its most simplistic-core; if quantization is involved then it must be digital transmission (context being analogue signal), and DSD relies upon 1-bit quantization and aggressive noise shaping.
Edit:
BTW how do they overcome the dither challenges with DSD?
Cheers
Orb
Why would the noise shaping be any more aggressive for DSD than other 1-bit, or even multibit, delta-sigma converters?
What dither challenge? Dither comes for "free" in most delta-sigma loops, circuit noise... Often encoding on the ADC (source) side.
What dither challenge? Dither comes for "free" in most delta-sigma loops, circuit noise... Often encoding on the ADC (source) side.
Because of the noise-distortion characteristic of DSD compared to PCM (talking how both used in the music/audio industry-products).
The dither challenges I am alluding to relate to the papers done by Lipschitz and Vanderkooy, I appreciate Bruno had done one back in 2002 that covered the benefits of DSD but cannot remember if he also touched upon dither.
Also is there any impact from multiple iterations of dither if bouncing the signal between DSD and PCM and finally back to DSD for editing in the studio?
I know some feel reiteration of dither (only anecdotal tests involving several types) is noticable even with PCM.
Cheers
Orb
Nor am I Don,
I am happy if we get both formats tbh, that way we have a choice on the sound preference for any album released.
Both formats I would say have serious technical considerations where PCM is further compounded by what is the "right" filter; I am now recently a fan of some newer filters that are a combination of linear/minimum phase.
Cheers
Orb
I am happy if we get both formats tbh, that way we have a choice on the sound preference for any album released.
Both formats I would say have serious technical considerations where PCM is further compounded by what is the "right" filter; I am now recently a fan of some newer filters that are a combination of linear/minimum phase.
Cheers
Orb
The fundamental problem for PCM is there are no good native PCM A/D converters available today, outside of the few remaining Pacific Microsonics PM1 and PM2, and virtually no labels using those that are available. The available ADC's today are all multi or single bit PDM, that must be decimate filtered from their sampling rate to whatever PCM rate is used for the recording. That filtering process is quite discernible. IMO, that effect is far greater than the perceived problems often associated with DSD.
It is academic tbh.
DSD is converted for editing, and as you say we have Delta-Sigma ADC influencing PCM.
What we can focus on though is the behaviour of the signals in the real world studio and the associated processes, and implementation at the DAC including architecture.
How many recordings do you have that you know for sure are really native DSD from ADC-recording-DAW-mixing-mastering-to consumer digital file without any conversions?
The filtering process in your context should only be discernible once you drop below a certain bit depth and sampling rate (Bruno Putzeys has done an article based upon research when at Philips Research lab where it is transparent transcoding between them); 16bit/44khz is not applicable to any of these discussions IMO as it is flawed in terms of constraints applied to digital filters, that is one reason PCM hirez can be better than CD quality with implementation of ideal reconstruction filters that do have notable slow rolloff.
Anyway there are quite a few DSD albums that came from DXD master file, and ironically on another forum where some listened to both the DXD and DSD they preferred the latter.
Same can be said there are PCM hirez downloads that came from DSD master file.
Cheers
Orb
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