DSD, WDSD and DXD

[soloan]

I've read through some articles about DSD recently including something from Merging and the Sadie manual. They said it is no way to edit in DSD64. So Pyramix has to change them to DXD format which is 24bit,325.8kHz while Sadie would do it in 8bit,2.8Mhz when editing and processing. What does that mean? Do they mean after editing, the file is no longer standard DSD?

[Don S]

Pretty much! DSD does not use any PCM filters. Once the signal is altered in any way it is no longer DSD. However, Merging's solution was to be realistic about DAW use. Not many people have ears and equipment to hear the difference between 325.8 and DSD. I'm not 100% sure if Pyramix samples back up to DSD, but it would have to in order to keep the rest of the file at DSD.
Check out www.merging.com forum. I've read a couple posts about that subject.

[Sounds Great]

Originally Posted by Don S

Not many people have ears and equipment to hear the difference between 325.8 and DSD.

Isn't it still going PCM, though? I have a feeling PCM conversion is where the problem lies, at any bit or sampling rate.

[Don S]

Yes, you're absolutely right! It is now PCM. I guess they figure the difference in audio quality would be almost identicle for the fractions of the file that would be PCM. From what I understand, once you splice and cross fade, the xfade becomes PCM for that split second. Or alter the original sound in anyway - you're in PCM.
I hope this helps, but I encourage you to visit the forum to get more accurate info.

Don

[tINY]

DSD is DSD and PCM is PCM. You can convert between them and back - it's just math. If you have a DSD recording and want to process it on regular 24/96 equipment, you can convert it and, after you are done processing it, you can convert it back to DSD.

The 1-bit DACs and Delta-Sigma ADCs have been doing this for years already.



-tINY

[the1Hub]

there is actualy a good reason for merging audio to do this. first is it is all about the math, the better the math the better the conversion. second merging belives that there is no audible diffrence between there DXD and others 8bit 2.822mhz. there for they can run a computer more efficently at the DXD format. better perfromace. now the first thought i had when i herd this was, wouldnt the 2.8mhz give you better frequency response? according to nyquist the anwser is yes. (for those not familier with nyquist its a simple rule that governs pcm audio. that you can only use half of the sample rate to get your frequency response. example if your sample rate is 44.1 then the highest frequency you could use with that sample rate would be half, or 22,050 hz. sorry for the bad/incomplete explination somebody can probably do a better job in another post.) so back to the question at hand why merging audio uses a sample rate of 325.8. so with nyquist you could summize that the sadie would be capable of reproducing a frequency of 1.4mhz while the DXD format would only beable to create 162.9 khz. now you say wow big diffrence right. well yes but in wonderfull world of dsd a little friend comes around again. dither. what ends up happaning is that it requires so much dithier to make a 1bit signal usalble it will make analog gear. ie speaker, outboard gear, meters. perform strangly even though the sound of the dither is well above human hearing range. so the solution to this is to add a 80-100khz lowpass filter. so all of that extra bandwidth on the sadie just went out the door, as well as about half of the availble bandwidth of the pyramix DXD. and as a final asult to your frequency response. philips in thier licensing agreement for a sacd player recomends another lowpass filter at 50khz. at the analog output.
if i left something out iam sorry but ithink that should about cover it.
lots of good information here about dsd editing in genral.
http://recforums.prosoundweb.com/ind...d470d8765b9cbe

[Sounds Great]

Originally Posted by the1Hub

and as a final asult to your frequency response. philips in thier licensing agreement for a sacd player recomends another lowpass filter at 50khz. at the analog output.
if i left something out iam sorry but ithink that should about cover it.

Well, ok. I don't understand lots of that, but your end statement, low pass filter at 50K?

This is a problem? I can't believe anything is needed above 50k. But there does seem to be something happening in PCM that is not happening in DSD.

[the1Hub]

Originally Posted by Sounds Great

Well, ok. I don't understand lots of that, but your end statement, low pass filter at 50K?

This is a problem? I can't believe anything is needed above 50k. But there does seem to be something happening in PCM that is not happening in DSD.

first the 50khz lpf is after the signal has been converted back to analog. philips says it is to protect speakers that might have not been designed to handle transients over 100khz.

as for having an impact on the quality of the the sound iam hearing from more people that it dose. basicly what ive been hearing, and this is vary new to me as in the last couple of days, is that your brain dose not percieve transients with frequencies over say 20khz as sound but that it will use them in determinig direction and distance. there for the impact would be found in the percivied clarity of the stereo image and depth of a recording. but like i said iam just learning about this recently. one day we might try some test on this if we have time.

sorry for the vary sloppy post eariler. i need to not respond to post at 2:30 in the morning.

[tINY]

Think of the formats this way:

Using a perfect 48kHz LPF, the output of 24/96 audio integrates 2 samples for the output at any given time (not quite, but close enough for now) which gives you a dynamic range of 150 dB

In DSD, that same, perfect, 48 kHz LPF would integrate 60 samples for about 360dB dynamic range. If you move your filter up to 96 kHz, you get 6dB less and so on. At about 320 kHz, you are integrating about 9 samples for 54dB of dynamic range., where the dynamic range of 8 bits is 48dB.

Math, I say....

The only difference is the encoding and the hardware you use going in and out of the real world.



-tINY

[MBishopSFX]

I work almost exclusively with DSD on an everyday basis and have since 1996 and have worked with every DSD recording system and workstation made so far.

There is a HUGE difference between how SADiE and Pyramix handle DSD editing. Same for Sonoma vs Pyramix.

All start with a 1-bit DSD source. All can deliver a final 1-bit DSD "master." How they get there is a different story, though.

The Pyramix, the instant you put the system in edit/mix mode, converts the DSD source to 24bit,325.8kHz pcm for all editing and then re-converts back to DSD for the output to DACs or mastering. All DSD audio, from beginning to end of what you're working on, has gone through the conversion/re-conversion process. This is NOT just simple math being performed. The audio goes through internal pcm and sigma/delta converters for the process.

SADiE (or Sonoma) keeps the DSD source as DSD (no conversion) except at the actual edit crossfade, where an insert occurs the length of the crossfade of 8bit,2.8Mhz pcm and back to DSD. This conversion occurs ONLY at the crossfade. All DSD source on either side of the edit is untouched as long as the "bypass mixer" button is pushed (how I almost ALWAYS run the SADiE DSD). I defy anyone to hear the conversion effect for the duration of an edit crossfade! However, even if the mixer is inserted, the audio integrity is more transparent than that of the pyramix to MY ears. There is no low-pass filtering used or needed. The "annex" DSD metering verifies there is no increase in UHF noise.

(Here's where I pull on the flame-proof clothing ) In MY experience, there is a big difference in how these system sound as well. The Pyramix, as soon as the DSD source hits the 325 mHz pcm mixer (that's every mode other than source recording), changes the sound in an unacceptable manner, IMO. Philips and Pyramix claim otherwise, but I have had 6 very experienced DSD editors and skilled listeners here pick out the Pyramix vs SADiE or Sonoma audio every time. The SADiE and Sonoma keep my DSD source intact.

As with any tool in any format, taking care in how intrusive one is on the source audio will make a difference in the final outcome. The vast majority of my DSD projects can stay in native DSD except for the edits. For any processing or mixing, I come out to analog via EMM Labs dacs and record the process or mix back to DSD via EMM Labs adc. All properly-designed analog gear has no problem whatsoever with the DSD source - no low-pass filtering needed here either! This conversion to analog and back in MY experience is actually less intrusive than the Pyramix 325 mHz conversion process (I'm pulling on the second layer of flame-proof clothing...). Others may disagree (they may own a Pyramix), but this is the way I hear it!

[cdog]

Originally Posted by MBishopSFX

I work almost exclusively with DSD on an everyday basis and have since 1996 and have worked with every DSD recording system and workstation made so far.

Michael,

Thanks for the response - that was very interesting, as not many people here have EVER used DSD, much less every DSD system. Please tell us more about your work.

My experience with was: sounded great, found out it could only be mixed on a analog desk or esoteric workstations, got bummed, cried in my PCM filtered beer.

With some notable excepetions, most people here consider DSD unpractical as a recording and mixing medium for various reasons. Seeing as though the technology has been around for 10 years and still very few professionals are using it (for recording/mixing), is there any hope for the future of DSD as a popular recording format (not just for fringe wackos like Steve )?

Or will it remain the domain of archivists?

Cause honestly, Pink on DSD is NOT going to sound better than Pink on CD, as it was all recorded and mixed in PCM, and 2" tape is going the way of the Dodo, if it already hasn't.

[mwagener]

Originally Posted by MBishopSFX

I work almost exclusively with DSD on an everyday basis and have since 1996 and have worked with every DSD recording system and workstation made so far...

Michael

great to see you here. Thank you for this very informative post. There is so much "mystique" surrounding the DSD/SACD format, I'm thankful for every bit of clarification.

[the1Hub]

Originally Posted by cdog

Michael,

Thanks for the response - that was very interesting, as not many people here have EVER used DSD, much less every DSD system. Please tell us more about your work.

My experience with was: sounded great, found out it could only be mixed on a analog desk or esoteric workstations, got bummed, cried in my PCM filtered beer.

With some notable excepetions, most people here consider DSD unpractical as a recording and mixing medium for various reasons. Seeing as though the technology has been around for 10 years and still very few professionals are using it (for recording/mixing), is there any hope for the future of DSD as a popular recording format (not just for fringe wackos like Steve )?

Or will it remain the domain of archivists?

Cause honestly, Pink on DSD is NOT going to sound better than Pink on CD, as it was all recorded and mixed in PCM, and 2" tape is going the way of the Dodo, if it already hasn't.

I think DSD will get more and more use as time goes on. first as (and if) tape goes the way of the dodo there will be demand for higher quality digital recording. also as processing performance increases you will see more and more use of DSD daw. we all ready are starting to see the first albums recorded and mixed all to DSD with units capable of playing back and recording of more then a few tracks at a time. and as file sharing software contiues to cause losses of profits for the record companies i think you will see a shift to formats like SACD that have very strong copy protections built in.

[Sounds Great]

Originally Posted by cdog

Cause honestly, Pink on DSD is NOT going to sound better than Pink on CD, as it was all recorded and mixed in PCM, and 2" tape is going the way of the Dodo, if it already hasn't.

I have to disagree. Even when recorded in multi-track PCM, tracks *can* sound better before being mixed together into 2 track PCM.

One of the things I have noticed with PCM is that a solo track can sound pretty good on it's own. I think the more complex a waveform becomes (numerous tracks mixed together), the harder time PCM has of "recreating" it.

You will notice how many complaints people have about "mixing in the box", and I think this is the reason.

And some instruments with very complex waveforms going on, such as an acoustic piano, can highlight this problem on their own.

[cdog]

Originally Posted by the1Hub

I think DSD will get more and more use as time goes on. first as (and if) tape goes the way of the dodo there will be demand for higher quality digital recording. also as processing performance increases you will see more and more use of DSD daw. we all ready are starting to see the first albums recorded and mixed all to DSD with units capable of playing back and recording of more then a few tracks at a time. and as file sharing software contiues to cause losses of profits for the record companies i think you will see a shift to formats like SACD that have very strong copy protections built in.

Maybe, but to me the problem starts with a public thats more eager to spend their hard earned $$$$ on ipods and PSPs than on a high fidelity home system. Fewer and fewer people listen to music as an activity, most people listen to music as background noise when working out, driving, etc.

If nobody I know who is going to buy my album has a SACD player, why should should I (or my small label) spend the extra $$$$ for a dual layer disc? Especially seeing as though all the music is recorded and mixed in PCM.

Don't get me wrong, I think the DSD technology is very promising, it sounded great in my limited experience with it, and I would love to embrace it. But I have to let Sony/Phillips do the heavy lifting for me by getting these SACD players into peoples homes and cars, selling them on the back their huge backlog of classic analog recordings that can be remastered in DSD.

By the time everyone has a SACD player, hopefully DSD recording and mixing will be as simple and cost effective as PCM is now.

[tINY]

DCD will not make it. DVD audio formats will see to that....

For that matter, simple stereo may go away in the next 20 years as well. HK and others are pushing the x.1 formats - all of them use PCM with a compressed format options for side and rear channels.



-tINY

[MBishopSFX]

Originally Posted by the1Hub

I think DSD will get more and more use as time goes on. first as (and if) tape goes the way of the dodo there will be demand for higher quality digital recording. also as processing performance increases you will see more and more use of DSD daw. we all ready are starting to see the first albums recorded and mixed all to DSD with units capable of playing back and recording of more then a few tracks at a time. and as file sharing software contiues to cause losses of profits for the record companies i think you will see a shift to formats like SACD that have very strong copy protections built in.

We've used the Sonoma 24-track DSD workstation on four projects in just the past month - and this is a 'small' indie label. As I understand it, the 24-track is being pushed to 64 tracks soon. The drawback is the converters needed, but that's true with pcm, too.

To me, the DSD 24-track is the best alternative to 2" analog - and a lot more versatile!

[Plush]

As one who has consistently downthumbed DSD recording and its attendants,
we have been seeing mightily increased interest and demand for SACD from Euro classical record companies. We can supply those SACD masters since these companies don't care if the original recording was DSD or PCM.

Early into DSD in 1998, we had in the past dumped all of our DSD recording equipment except the converters (dCS). A house of SADiE, we are perfectly happy with the way it handles pcm files and edits.

Ironically, for fairly cheap money, there are two new pieces of gear in house that will allow us to resume SACD work. The NEVE 1073 DPD and the T(rash)cam DV-RA1000. Imagine that---cheap power to the people DSD!

I posit that the only important thing is delivering to the consumer on SACD since this is what is easy to convince the record company to buy.

As far as Pyramix is concerned, the hand wringers who decry the system should talk directly with the designer, Claude Cellier. The mind behind Pyramix, Claude is focused on good sound and has the down to earth manner (and huge brain) descriptive math skills to explain it to you.

Pristine this, pristine that---I hate that word---it should just be a girl's name!
Those who continue to hold out that the holy sonic grail can ONLY be *pure* DSD will simply lose market share as we swamp them in pcm sourced SACD and DVD-Audio.

[MBishopSFX]

Originally Posted by mwagener

Michael

great to see you here. Thank you for this very informative post. There is so much "mystique" surrounding the DSD/SACD format, I'm thankful for every bit of clarification.

Hi Michael,

Thanks! I'lll forever remember you 'saved' my session last year with the loan of the Royer 121s. Ever since, I've used various Royers in many capacities.

We're recording Hiromi again next month - this time at Blackbird. Spieden/Royers on the piano of course!

[MBishopSFX]

Originally Posted by Plush

As one who has consistently downthumbed DSD recording and its attendants,
we have been seeing mightily increased interest and demand for SACD from Euro classical record companies. We can supply those SACD masters since these companies don't care if the original recording was DSD or PCM.

Early into DSD in 1998, we had in the past dumped all of our DSD recording equipment except the converters (dCS). A house of SADiE, we are perfectly happy with the way it handles pcm files and edits.

Ironically, for fairly cheap money, there are two new pieces of gear in house that will allow us to resume SACD work. The NEVE 1073 DPD and the T(rash)cam DV-RA1000. Imagine that---cheap power to the people DSD!

I posit that the only important thing is delivering to the consumer on SACD since this is what is easy to convince the record company to buy.

As far as Pyramix is concerned, the hand wringers who decry the system should talk directly with the designer, Claude Cellier. The mind behind Pyramix, Claude is focused on good sound and has the down to earth manner (and huge brain) descriptive math skills to explain it to you.

Pristine this, pristine that---I hate that word---it should just be a girl's name!
Those who continue to hold out that the holy sonic grail can ONLY be *pure* DSD will simply lose market share as we swamp them in pcm sourced SACD and DVD-Audio.

There's nothing "pristine" about any recording system. I doubt there ever will be. The only "pristine" part of the recording process is the live performance going on in front of the microphones. Past there, it's an interpretation of what occurred. It's up to the individual to choose tools to get the job done, and there are many excellent tools in ALL formats to choose.

Out of any part of the recording chain, for ME, the recording platform needs to be as transparent as possible. If I choose to add color anywhere, it'll be with mic placement and/or choice, the venue we record in, or any outboard gear used, but I want the recording device to be neutral. For my work, the DSD SADiE or Sonoma fit that bill best.

The Pyramix is still quite a remarkable recording system, despite that I don't like what the internal process does to DSD sources. Pyramix has the best GUI I've seen. It's a really fast, efficient editor and an extremely versatile all-around system. Claude Cellier and Merging and Philips, all put together a terrific recording platform. Lots of excellent productions - pcm or DSD - have been recorded and edited/mastered on Pyramix systems. I had several discussions with Claude and others when the Pyramix was in for evaluation. Merging was kind enough to loan the system for a very extensive trial. It all came down to what I and several other users in our place preferred in the recording process. We chose the more transparent path, IMO.

If SACD went away tomorrow, I'd still be recording on a DSD system out of choice. I've got (up to) 192 kHz or analog multitrack systems I could be using, but I'm working with DSD.

[mwagener]

Originally Posted by MBishopSFX

Hi Michael,

Thanks! I'lll forever remember you 'saved' my session last year with the loan of the Royer 121s. Ever since, I've used various Royers in many capacities.

We're recording Hiromi again next month - this time at Blackbird. Spieden/Royers on the piano of course!

Great, would love to come and hang for an hour if that's ok. She is AMAZING, out of this world.

[YGoh]

Originally Posted by MBishopSFX

There's nothing "pristine" about any recording system. I doubt there ever will be. The only "pristine" part of the recording process is the live performance going on in front of the microphones. Past there, it's an interpretation of what occurred. It's up to the individual to choose tools to get the job done, and there are many excellent tools in ALL formats to choose.

Out of any part of the recording chain, for ME, the recording platform needs to be as transparent as possible. If I choose to add color anywhere, it'll be with mic placement and/or choice, the venue we record in, or any outboard gear used, but I want the recording device to be neutral. For my work, the DSD SADiE or Sonoma fit that bill best.

The Pyramix is still quite a remarkable recording system, despite that I don't like what the internal process does to DSD sources. Pyramix has the best GUI I've seen. It's a really fast, efficient editor and an extremely versatile all-around system. Claude Cellier and Merging and Philips, all put together a terrific recording platform. Lots of excellent productions - pcm or DSD - have been recorded and edited/mastered on Pyramix systems. I had several discussions with Claude and others when the Pyramix was in for evaluation. Merging was kind enough to loan the system for a very extensive trial. It all came down to what I and several other users in our place preferred in the recording process. We chose the more transparent path, IMO.

If SACD went away tomorrow, I'd still be recording on a DSD system out of choice. I've got (up to) 192 kHz or analog multitrack systems I could be using, but I'm working with DSD.

Thank you for your well explained post and personal experience, as I need that the most since it's quite difficult to listen to a DSD recording and mixing.

1.) So 8 bits 2.8MHz is PCM and not something DSD?

2.) Do you think that PCM 384kHz would not be as 'transparent' as the 8bits 2.8MHz Sonoma system?

[George Necola]

Originally Posted by the1Hub

I think DSD will get more and more use as time goes on.

I have to agree with Tiny here..

Sony told you in the late 90's that you need to buy a very expensive DSD console to work with this format. then they decided to close their prostudio-market (sony oxford boards and stuff).

no it's like "thank you that you purchased our DSD-gear.. you are fukked now".

I think it will be the x.1 or even x.2 standart, and there might be a small market for DXD. but maybe it will be "mp3 with ipod".

[YGoh]

Anyway, what is the problem with PCM format in general, assuming if we can get the sampling rate at 384kHz? Do we still have the dynamic range limit of only 24bits?

[YGoh]

Is the dynamic range and resolution of DSD higher than 24bits PCM though?

Here is a good read MBishopSFX, Surround Professional 2002 - Craig Anderson; DSD to PCM Comparisons

[mud5150]

Just my opinion but I think if we went to a format that could only be mixed otb and didn't allow edits we'd have alot more music that most people wouldn't consider background noise.

I apologize in that I have added nothing

[Sinewave]

Originally Posted by mud5150

Just my opinion but I think if we went to a format that could only be mixed otb and didn't allow edits we'd have alot more music that most people wouldn't consider background noise.

I apologize in that I have added nothing

[Plush]

DSD is now being recorded with a KORG and edited with some Mackie Traction soft.


Power to the people.
Down with Chinese Junque!

[videoteque]

Plush, are you sure you can edit DSD in Tracktion??

[Peter Scheelke]

Hi. My name is Peter Scheelke. I am one of the founders of DAD, Digital Audio Denmark. We are the manufacturer of the AX24 AD/DA converter and the Merging Sphynx 2 converter.
In the discussion about DSD/DXD, Sadie/Sonoma/Pyramix I can help clarify some of the advantages/disadvantages in the different audio formats.

DSD 64fs (the format used for SACD) is a 1 bit format with a sample rate of 2.8224 MHz (64 x 44.1 kHz). The main advantage of this DSD format is the as close to perfect as we have ever seen impulse response, which is just a little more than 100% measured with a 3us pulse, plus the very wide frequency band. The disadvantage of DSD compared to digital PCM is the noise performance and the fact that DSD can not be edited since it is only 1 bit.

In our AX24/Sphynx 2 we have been able to keep the noise down until 23 kHz (<-120 dBfs measured 20-20 kHz), however the energy from the noise is still part of the signal, so after 23 kHz the noise becomes increasingly significant.

Since DSD can not be edited as a one bit signal, it is necessary to convert to some kind of multi bit for editing. When converting back to DSD the modulator noise will be added again, and after just a few editing back and forth the audio will no longer comply with the noise performance specification stated in the Scarlet Book (specifications for SACD’s). DSD 64fs is used as recording format in Sonoma, Sadie and Pyramix DSD systems. (Pyramix can also record in DXD).

There is also DSD 128fs, also 1 bit, but with a sample frequency of 5.6448 MHz (128 x 44.1 KHz). Since it is a 1 bit signal, quantization noise is equal to DSD64, but since the frequency band is twice as wide, the noise is only half that of DSD 64fs within a given frequency band. With the same type of noise shaping as DSD 64 the noise will start rising at the double frequency. In our implementation the noise starts rising from about 46 kHz.

PCM 44.1-192 kHz/24 bit: Since all frequencies, at more than half the sample rate, will be mirrored around half the sample rate (aliasing), all PCM formats needs an anti aliasing filter. The normal anti aliasing filter is the 0.45/0.55 filter which starts at 45% of the sampling rate and has full attenuation at 55% of the sampling rate.

A major disadvantage in the normal 0.45/0.55 anti aliasing filter is that the filter is only attenuating 10-12 dB at half the sample rate (Nyquist), so frequencies between 50% and 55% of the sample rate will get mirrored around half the sample rate and will create new frequencies without any harmonic relationship to the audio. Another disadvantage is that some of the energy from the audio is lost in pre/post ringing; a stronger anti aliasing filter will create more pre/post ringing than a less intense filter. Since some of the energy is lost, the anti aliasing filter attenuates the impulse response.

Due to bandwidth a steep anti aliasing filter at 44.1 and 48 kHz sampling rate can be justified, however at higher sampling rates (96kHz, 192kHz) it would be better to use a less steep filter. All anti aliasing filters cause delay in the A/D converter which is about 0.8 ms at 44.1 kHz sampling rate with a 0.45/0.55 filter.

DXD is something new, a 352.8 KHz/24 bit sampling rate in the A/D converter intended for 32 bit floating point DAWs. Until now DXD is supported by DAD, by Merging in their Pyramix DAW, by AMS Neve in their new DFC PS/1 console, and in the Saracon SRC from Daniel Weiss, but also other manufactures are one their way with DXD equipment.
In our implementation we have chosen to add only very soft anti aliasing filter for DXD and for an even higher sample rate we offer, 384 kHz; since there is very little audio above half of the sample rate. Our implementation of DXD has a great impulse response (88% with a 3us pulse) and a significant better out of band noise performance compared to DSD64fs.
We think it’s a big step forward, offering far better impulse response that previous PCM, avoiding the filtering problems of previous PCM and better out of band noise performance than DSD. We think this is the future of digital audio.

Merry Christmas from Denmark to all audio lovers at Gearslutz!

Peter