Making the DSD Sausage: Different Recipes
My recent discussion of Sound Liaison and their DSD releases got me thinking about all of the ways that DSD recordings are produced. A subsequent email from the company, indicated that they take their original 96 kHz/24-bit PCM recordings and convert them to DSD 64 through an analog process, “We do a D/A/D transfer using high end converters” was their response. As we already know, any conversion degrades the fidelity of the original sound. The method used by many companies is to take perfectly wonderful high-resolution PCM recordings and play them back using the best digital to analog converter available. The analog signal is then immediately converted back to a digital format, except this time it’s a PDM (Pulse Density Modulation format) 1-bit DSD file running at 2.8224 MHz (64 times the sample rate of a standard CD…which means absolutely nothing when it comes to “resolution”). This newly converted file is then prepared as both DSD-dff and DSD-dsf files for download sale…usually with a premium price tag.
However, this is not the only way to produce and release DSD recordings. Most of the SACDs and DSD files available for downloading started life as analog recordings. The last time I looked at the catalog of DSD recordings, over 85% of the available albums were transfers from older standard definition masters. So recipe number 2 for creating a DSD file is an archive of a preexisting recording. And the fidelity of the new “more analog like” DSD master? It’s the same as the second or third generation tape from which it was made.
The DSD vs. high-resolution PCM “shoot out” that I was involved in at Snow Ghost studios in Montana a couple years ago (you can read my post by clicking here) demonstrated another method of recording a DSD project. The source microphones were routed through an analog SSL console to a 24-track DSD 64 Sonoma system by way of Meitner analog to digital conversion. When it came time to mix the multichannel DSD tracks to stereo, these same tracks were converted back to analog and blended in the SSL console (which was a special version with high-frequency low pass filters included to help with the ultrasonic noise inherent in the 1-bit encoding process). Finally, the stereo bus outputs of the SSL analog console were digitized once again to DSD.
Along the way, each of the analog tracks was subjected to some additional signal processing. During a mixdown session, it is common to add a little EQ or compression. Even if neither of these were used, a mixer will always add a little artificial reverberation (studios are relatively dead acoustically). Would you be surprised to learn that ALL of the outboard reverberation units are PCM based? It shouldn’t because we know that DSD cannot be used to create reverberation. In fact, on the Merging Technologies website, they acknowledge, “DXD is a 352.8 kHz/24bit audio signal, which is used to be able to seamlessly move a DSD signal into PCM (standard method of digitizing audio) world so EQ, dynamics and other effects processing can occur.” One of those other effects is reverberation. Many labels take this route to produce DSD releases. It’s crazy!
I can’t figure out why any producer would subject their recordings to so many conversions and modifications. Each conversion step degrades the fidelity of the final product. Maybe this is why people like the “sound” of DSD.
The methods discussed above are not native DSD recordings although some high-end labels would have you believe they are and they charge a premium for these converted DSD files. Native DSD recordings do exist…but they are extremely rare. My best guess is that there are less than 1000.
We’ll explore this further tomorrow.
All true. I think the ‘aura’ of DSD has been generated from several vectors. First, since too many just ignorantly don’t like ‘digital,’ the basic LPCM format/method has unwarranted ‘haters.’ Any method that can be linked to the word ‘analog’ appears favorable then. I have compared SACD and DVD-A many times. The DVD-A is more truthful, but there is definitely a silky warmth on many SACDs, and it’s that sonic character that drives folks to think it’s preferable. They apparently are not concerned w/ all the ultra-sonic noise sitting not so far above the audio band. There’s almost a parallel between the DSD interest and the vinyl resurgence. Just my 2 cents, but again, all that matters is the results, no matter how they are obtained.
Thanks Craig…it’s undoubtedly true that marketers try to tie “analog” with DSD and “cold, harsh” with PCM digital. It’s absolutely not true but there you have it. I found it very interesting that the German study found that no one could tell the difference between SACD and PCM of the same identical track. What you and other hear is the result of different production chains.
Hi Mark,
Just for the sake of fairness and out of curiosity, how do the native DSD recordings – without or with minimal post-processing – of Todd Garfinkle fair in the fidelity and HRA department after conversion to PCM (and before)?
Here’s an excerpt from an Interview with Todd:
“I currently record on a Korg MR2000S which records DSD at double SACD quality, 5. 6MHz. I record everything like that, and from that point, having what I believe is a really high quality master, I can down-sample to PCM 176. 4 high resolution WAV files which you can listen to on your Hi-Res audio system.
Phil: So where do you stand on the issue of PCM versus DSD?
Todd: I record in DSD because I believe DSD as a master format is higher resolution than 176. 4 kHz PCM but there are very few people that can listen to DSD unless it is formatted and authored as an SACD which is another story.
Do you notice any deterioration in the quality of the recording due to the conversion process? Have you compared a PCM recoded natively against one derived from a DSD master?
I will soon have a new DVD-ROM produced from transfers of my analog record of the Goldberg variations I did do it in both PCM and DSD. We did the transfer twice. SADiE from England, which is now owned by Prism Sound I believe, and Pyramix, which is Merging Technologies from Switzerland they have computers that record and edit in DSD. For SADiE only the edit points are done in PCM and the rest is DSD. Pyramix does all the editing in DSD. But it’s $20,000 for a system like that, and I can make a few records for that money. . . ”
Cheers!
Todd is good friend of mine…we’ve known each other since we attended CSU Northridge 30 years ago. He makes very nice sounding recordings in churches, subway tunnels, and other exotic locations. He uses great microphones and a custom preamp into his Korg MR2000S, which is a consumer grade component. It’s not in the same league as Merging, Horus, Meitner, or Mytek…but it does the job. By recording at 5.6 MHz DSD, the noise is shifted further out of the audio band. It moves another octave higher. YOur eares don’t hear it but your equipment does.
He’s wrong about DSD b eing higher quality master format. is recordings would be better if recorded at 176.4 kHz and 24-bits and then converted later to DSD. Moving from DSD 128 to PCM at 176.4 is not a down sample operation…it is a format conversion and it degrades the sound. It’s required so that Todd (and anyone else using DSD can make edits and process the files).
It’s a complete waste of time to compare an analog recording made through the two systems he’s referring to in his interview. Todd’s a very small operation…costs are important just as they are for me.
Would the fidelity of Todd’s recordings make it to your HRA database, or has the conversion from DSD to PCM degraded the quality of the recordings below HRA standards?
I would include Todd’s recording in the database…with commentary and spectragraphs.
Another way of ‘creating DSD files’ is, what the german Stockfish Records do.
They feed the (PCM) recordings into a vinyl cutter, make a master and play this back for a DSD transfer – they call it DMM.
See this video:
http://youtu.be/HocWBv1g_fo
By the way – they do excellent recordings!
Greetings
FB
I wrote about this approach some many months ago. Very complicated and unnecessary in my opinion. In the video, they show Sonic Soundblade PCM software, EQs, filters, reverb units and lot of steps to get to a sound the like. I’m much more in favor of a natural sound without all of the processing. The original PCM would have much more dynamic range and spatial diversity. They have a good reputation…so it much be working.
I admire your work and your highly principled approach.
However, I sometimes wonder if by focusing almost exclusively on the details of the recording and mastering process, you are missing the bigger picture. People buy recordings that sound pleasing to them. Part of that pleasure undoubtedly comes from the technical “plumbing” that was used to preserve (we hope) as much fidelity as possible in the recording chain. But an equally large part comes from loving the artists, the repertoire and their performance of it.
You can’t make a great recording without both parts being in place, as my shelf full of unloved “Audiophile” recordings – great recorded sound but lousy material – testifies.
You make a very good point…if the music doesn’t turn you on then the best sounding recordings in the world aren’t going to find their way into your playlist. However, I wouldn’t regard any of my audiophile recordings as “lousy material”…perhaps not to your taste but I can listen to John Gorka or Laurence Juber over and over without getting tired of the music.
Mark,
I have to say I’m a bit confused now: why would anyone go through a DA-AD conversion chain to convert PCM files to DSD when there is conversion software out there which can do the same completely in the digital domain? For one, it’s so much cheaper to do and secondly I would assume that you loose so much less in the conversion process.
So where’s the flaw in my logic?
Best regards,
Oliver
There is conversion software, of course. Is it better than using a state-of-the-art converter? I can’t say. If the people at Sound Liaison like the sound of physical convertors, they can make that choice. They aren’t only ones…plenty of labels do this including 2XHD. In fact, in the earliest days of my own label, I would take the output of my Meridian DVD-Audio player over the software choices that I have available.
Hi Mark,
The other day I bought a couple of downloads from NAXOS, a label for whose recordings I have certain respect and truly enjoy. Today I sat down with some time to listen and browse through Pdf booklets, only to bump into another ridiculous example of BS audio “alchemy” at the bottom of one of the booklets: “2xHD Mastering”.
As a mastering engineer I can only imagine the faces you’ll make after reading about it: http://www.2xhd.com/index.html
It’ sad that a label like NAXOS has bought into the BS of exotic recipes involving degrading conversions back and forth to analog, DSD, DXD, and vintage equipments, tube Amps, etc.
I had a laugh that scared of my cats when I read the following:
“The process begins with a transfer to analog from the original 24bits/96kHz resolution master using cutting edge D/A converters. The analog signal is then sent through a hi-end tube pre-amplifier before being recorded directly in DXD using the dCS905 A/D and the dCS Vivaldi clock. All connections used in the process are made of OCC silver cable. DSD and 192kHz/24bit versions are separately generated, directly from the analog signal.
2xHD was created by producer/studio owner Andre Perry and audiophile sound engineer Rene Laflamme.
Feel the Warmth
http://www.2xHD.com”
What a MESS!!
Anyhow, I’ll leave it for you to comment.
Cheers!
I’ve written a couple of times about the 2XHD guys…it’s amazing that they can make claims such as they do by simply remastering an old recording.