Dr. AIX's POSTS — 13 June 2015

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What’s going on over at Computer Audiophile? I know many of you are active readers of my site and Chris’ CA site. I try to stop by there every so often and see what’s brewing. In general, I’ve found the heat a little high for my sensibilities…and some of the “facts” expressed are more personal opinion than bona fide information. But what could possible prompt the CA community to post 530 comments on my assertion that 96 kHz/24-bit PCM surpasses DSD 64? A sophomore member of CA titled his thread “Mark Waldrep is claiming that PCM 24/96 is superior to DSD” and then went on to copy my entire post from April 11, 2105…the one that took issue with Sound Liaison for upcharging its customers for DSD version of their source 96/24 PCM recordings.

He asks a simple question, “Mark Waldrep is claiming that PCM 24/96 is THE format and that DSD should be cheaper than PCM. Comments? Is he right or just promoting his Itraxx pcm recordings?”

The simple answer is yes, if you consider the technical specifications between the two formats (never mind that you can’t actually produce most recordings in DSD because of the lack of tools). PCM recordings made at 96 kHz/24-bits have greater frequency response and dynamic range than DSD 64 tracks. The noise shaping required to increase the dynamic range beyond 6 dB (the result of 1-bit encoding) in the “audio band” is deposited just above the top of our hearing range. Look at the spectra of a typical DSD 64 track below:

150613_dsd_64_spectra

Figure 1 – A spectrograph of an “audiophile” DSD 64 recording. [Click to enlarge]

The purple “haze” in the high frequency area of the left hand spectral displays are the ultrasonic noise…put there by the noise shifting. It’s supposed to be out of the “audio band” but there is no “audio band” for your playback equipment. Imagine how your electronics and tweeters feel when this type of recording comes along…all analog sounding and warm. You bet. The graph on the right is a big side letter “V”. At a point just above 23 kHz, the line steadily rises almost back to where it started. Welcome to DSD 64. Any resemblance to high-end audio is purely coincidental.

What about dynamic range? DSD can actually eclipse a CD in dynamics AFTER the noise is plowed out of the way. But it doesn’t come close to the theoretical 144 dB that 24-bit PCM can achieve. Those specs are great for recording engineers like me but the fidelity of your system will never benefit from 24-bit DACs or fidelity. There simply are no recordings being released that have that much dynamics and your room couldn’t handle it if they were.

The answer to the question posed back in April at CA is quite straightforward. How is it possible for Chris’ reader to spin out 530 comments arguing about a true statement? I haven’t read all of the comments. The ones that I did read focus on the personal preferences of readers for the “warmth and analog sound” erroneously attributed to the DSD format (remember the study that determined that no one could tell the difference between mics split to a PCM rig AND a DSD rig).

I guess We should all feel pretty good about this blog site…I couldn’t make it through the approval process for 530 comments! Thank you for understanding the basics.

Have a nice Saturday evening…Charlie’s excited because our daughter is coming home today.

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About Author

Dr. AIX

Mark Waldrep, aka Dr. AIX, has been producing and engineering music for over 40 years. He learned electronics as a teenager from his HAM radio father while learning to play the guitar. Mark received the first doctorate in music composition from UCLA in 1986 for a "binaural" electronic music composition. Other advanced degrees include an MS in computer science, an MFA/MA in music, BM in music and a BA in art. As an engineer and producer, Mark has worked on projects for the Rolling Stones, 311, Tool, KISS, Blink 182, Blues Traveler, Britney Spears, the San Francisco Symphony, The Dover Quartet, Willie Nelson, Paul Williams, The Allman Brothers, Bad Company and many more. Dr. Waldrep has been an innovator when it comes to multimedia and music. He created the first enhanced CDs in the 90s, the first DVD-Videos released in the U.S., the first web-connected DVD, the first DVD-Audio title, the first music Blu-ray disc and the first 3D Music Album. Additionally, he launched the first High Definition Music Download site in 2007 called iTrax.com. A frequency speaker at audio events, author of numerous articles, Dr. Waldrep is currently writing a book on the production and reproduction of high-end music called, "High-End Audio: A Practical Guide to Production and Playback". The book should be completed in the fall of 2013.

(16) Readers Comments

  1. Tried CA for a while, but it just takes too much effort to separate truth from myth around there. Got exhausted, left, haven’t been back.

  2. The argument reminds me of the days when noise ruled turntables (and still does). Yet they swear that analog records (high fidelity direct cut mastered) beats digital despite the higher dynamic range simply because of it’s warmth (tubes anyone?) brought about by compression. We don’t want the rumble of true bass making that needle jump out of it’s grooves. etc. (tubes anyone?) Speaking of specs Bose fans still swear how much better those bass waves are as well as the whole spectrum of sound despite the company never publishing readouts. It seems that people will use any means necessary to quantify things they hear to justify their purchase despite evidence to the contrary that Bose is nowhere near true bass. So if I were you I would remember to take it all with a grain of salt. Facts seem to always get in the way of people’s beliefs. Have a good one.

    • Thanks Rodrian…the arguments are usually the same. The “emo” types don’t want to know anything that goes against their “hearing is believing” stance.

  3. I’ve pretty much given up on participating at CA because of this. I still go there to learn what I can, but trying to have a reasonable discussion is pointless. The lunatics (subjectivists) have taken over the asylum. Ironically, when I posted in a thread re: analog vs digital that in addition to all the convenience and cost benefits to digital vs analog I just thought digital sounded better, I was shouted down and told that I obviously had no clue, and that analog OBJECTIVELY sounds better. The irony of this out of the mouths of people who basically have accused me of being a troll for suggesting that I can’t hear much benefit to “hi-res” vs redbook, at least on equipment I can afford, on a site called COMPUTER audiophile, is not lost on me. Thanks for keeping it real in the current vernacular.

    • I was surprised to see all of that discussion going on over an article I wrote here. Why not ask me directly?

  4. It’s very simple – the “warmth” they love is the sound of shaving off all the high frequencies they regard as “cold.” They prefer the red end of the spectrum to the blue.

    Analog isn’t dripping with cool, it’s dripping with “warmth.”

    Check out the Audioholics web site instead – those guys seem to be immune to the snake-oil sales pitches and know what they’re talking about. Never mind that one of the two guys who do their video blog together appears to be a body-builder – they’re for real.

    • I know both Gene and Clint at Audioholics…been a few years since I’ve been in touch. I like their work.

    • Hi Phil, the ‘cold’ or ‘warm’ thing has another and more valid basis for preference than one might think, and here’s why. When we hear acoustic instruments live, we are generally at a distance where what is called “concert hall balance” exists. If you are sitting in row 16 in a fine hall, the spectral balance that would read on an a spectrum analyzing device would likely be quite smooth as it should be and would also show a steadily falling response past 2khz. Close-up microphone technique as is so common records a very different balance, with overtones and upper harmonics being a far more overt sonic presence. The red folks want things to sound more like they actually do in real life auditions , and the blue folks want to hear every tone and squeak that was recorded, although it would never sound that way in typical performance environments. I hope that helps. There’s sometimes a bit too much politics on these pages, and not enough reality factors included.

      • There are lots of different ways to record an ensemble. Some think two microphones (a stereo pair) placed 10-15 feet behind the conductor will give you best recreation of the orchestra in a hall…a sort of sonic documentary. The distance from the mics to the instruments is substantial and the high frequencies are attenuated. The audience doesn’t get to hear the sound that the conductor hears. The commercial world of music production uses lots of tracks and microphones placed much closer to the instruments. The resulting sound is more intimate, more accurate to the actual sound of the instruments, and contains more high frequencies.

        However, what Craig fails to realize is that we don’t place our playback speakers 6 inches from our ear…they exist at some distance away from our ears. I’ve written several posts on this issue. When the close up instrumental sound is reproduced by a speaker, the speaker becomes the instrument. The sonic experience for the listener is as if the instruments are 8-10 feet away from them…an ideal location for a “private concert”. When I played “The Pines of Rome” for conductor Zdenek Macal he was thrilled and said, “this is the first time I’ve heard music sound so real!”

        There “warmth” of DSD is a myth. It’s a market effort that is being perpetuated by the press and companies in a desperate attempt to appease the “anti-digital audio” crowd. High-resolution PCM is more accurate, contains less noise, can actually be produced natively, and dominates the world of recording. I wouldn’t be surprised if 99.9% of the recordings made on the planet are made using PCM.

  5. It wasn’t too long ago that I found out about the CA site and started following some of the posts there. Because of their name I had high hopes that much of what was written there would follow a common sense approach and be based solidly in the scientific arm of testing and review. Sadly for whatever reasons, I find the community there to be becoming more and more closely aligned with the lunatic fringe of the High End.
    Can’t judge a book by it’s cover I guess.

    • Chris Connaker, the founder and operator, of the site has built a solid reputation among audiophiles…especially the computer oriented guys. But the community runs into trouble more often than not.

  6. From my experience I’ve found that the type of person who won’t listen to reason, or is unwilling to take on board new information, is a lost cause; it seems to me the CA website is a magnet for this type of personality. Just let them bask in their ignorance and instead teach those who are open-minded, willing to learn and smart enough to see reality for what it is.

  7. Mark- I really enjoy your comments. I have a question about this one.
    “Imagine how your electronics and tweeters feel when this type of recording comes along…all analog sounding and warm. ”

    What evidence can you provide, us-the readers, to this statement?

    I think I understand what you are saying, there is an over-load in noise beyond the human audio perception extremes. Still, how does one go about showing interaction of this noise? Why would any engineer even think this noise at the extremes was a good idea for mass consumption- if it meant potentially damaging equipment?

    Thanks, I look forward to you reply. Bill

    • There is a great deal of ultrasonic energy that will cause problems with your equipment. I had a very interesting conversation with an engineer that told me they forgot to implement the digital filters in their high-end cellphone and some of the DSD derived content caused it to flip out. Luckily they caught in time. It’s crazy…even the SONY engineers put low pass filters on their own SACD players to protect them from the noise.

      • Mark- Thank you for your reply.

        I’m not a real DSD user and the only thing I have is an first generation Playstation 3 that plays SACDs (which transcodes DSD to 192Khz / 24bit PCM on-the-fly, ha!). I have transcoded a few tracks from 96khz / 24 bit to DSD using Korg’s AudioGate 2.3.4 software. I was curious at the time and I had some blank DVDs lying around and, in 2010, I had rarely heard anything beyond a CD and own only two SACDs. It was super easy to take a download a convert it to a DSD file and create a DSD disc-which is playable in the PS3. Sounded good, however it was a rock album and it used a different mix and master than my CD version. I have no reference.

        I say all that to tell you, your comments about DSD are enlightening. Especially the facts that show most of the “art” is made in the PCM realm, although there are a few very rare exceptions. I can’t seem to find a single spot to find a collection of your comments about DSD? I humbly request you create multi-part info post about DSD and put some clear facts to “myth bust” much of the crowd on MANY internet forums- You are widely discussed- keep up the fire and hard work. Bill

        • I have created a DSD-Facts.com website but haven’t put anything up. The allied forces for DSD are a rabid and powerful group.

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