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.

12 thoughts on “DSD Best Practices

  • November 19, 2014 at 6:18 pm
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    No question you know your stuff re DSD/PCM.
    One only has to compare a quality SACD with a quality DVD-Audio disc to hear the different format characteristics. SACD has a silky, smooth, slightly warm character, thus the comparisons to analog. High-rate PCM simply sounds like music w/o the digital nasties. It’s back to the old saw; truthful reproduction and easy listening are not the same thing, and many audiophiles don’t want to know this. While I like the sound of sacd, 24/96 etc. done right is more faithful to the original sound. As we have shared previously, the hang-up w/ this tight definition of hi-res is that 80% (at least) of the music that folks would like to hear at master tape level was or is recorded on analog tape, and hearing a download that pretty much cloned the master is a thrill that the public should not be kept from having due to semantic issues. It’s like trying to put a foot in a shoe that is too big. It’s not the foot’s fault; shouldn’t have used such a big shoe. Shouldn’t have called it hi-res either. “First Gen Sound” would have covered all bases, everybody gets what they want. I have said it before; try and look at the big picture Mark, not just what the ocean looks like from one dock with one ship attached. Thank You.

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    • November 20, 2014 at 10:11 am
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      The studies that have tried to establish a sonic difference between DVD-Audio and SA-CD have found not the “silky, smooth, slightly warm character” present in either format. In fact, the test subjects were unable to tell any difference. With regards to the percentage of real high-resolution audio available to consumers, you’re right that 80% of the masters (especially the older masters) are never going to be high-resolution. And that’s as it should be. Nothing wrong with hearing the studio masters in their original fidelity. No one, least of all me, is trying to deny audio enthusiasts from enjoying their favorite music at the best possible fidelity…I just prefer to be informed about the actual resolution of the transfers. It’s hard to spin things any other way.

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  • November 20, 2014 at 2:20 am
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    Hi Mark,
    I appreciate very much your clear words about the ‘myth’ of SACD!

    Could you – maybe – make a comments on the ability and quality of the multichannel part of the SACD.
    This might (?) be a reason for choosing a SACD version over a CD version.

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    • November 20, 2014 at 10:12 am
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      I’ll try to get a post up about the multichannel aspects of SA-CD. I don’t believe the MCH capability has much to do with the format’s success or failure.

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      • November 24, 2014 at 8:46 pm
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        I for one would have zero interest in SA-CD if not for multichannel. I’ve done hours and hours of A/B testing to see if I could discriminate between SA-CD stereo and the stereo RBCD layer that’s standard on almost every SA-CD, and I couldn’t reliably hear any difference.

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        • November 25, 2014 at 9:20 am
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          The multichannel aspect is a very positive one…just wish they chose PCM instead of DSD.

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  • November 20, 2014 at 7:51 am
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    Dear Dr. AIX,
    “In reality, a well-done CD captures virtually everything that a DSD 64 can.”
    OK. But, how about a multi-channel SACD?
    What are the options for a MC SACD lover like me?
    All the best,
    Ricardo
    (from Salvador, Brazil)

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    • November 20, 2014 at 10:13 am
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      I’m a multichannel advocate as well. I prefer to get DVD-Audio or Blu-ray discs for my surround music. Any SA-CD surround will most likely have come from analog originals sources. Just give the mixes in PCM.

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  • November 21, 2014 at 9:51 am
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    Just to check things out, I downloaded an album from Channel Classics in DSD64. The recording was captured straight from the analog mixing board in DSD. No PCM processing or I wouldn’t have bothered. MY DAC does not do DSD but Audirvanna converts it to 24/176.4 for my DAC to process. Yes, it is a warm sound but lacking in HF detail and air. I compared it to a 24/192 captured recording of similar material which has more spacial detail and a less rolled off sound, which to these ears sounds more lifelike. I have been an audiophile kind of guy since the 80’s and I can see why some audiophiles love DSD as being older guys, their setups are too bright and the DSD sound fits right in to their systems. To me, the good PCM stuff sounds more like the live sound I experience at venues, especially small classical and jazz venues. On this one trial their is no doubt that the DSD recording (of very fine music I might add) sounds very pleasing, just not as accurate as PCM. The good news out of all of this is at least, with computer based music, we have choices to pick the particular flavor that we enjoy. Some like warm sound. I want as accurate to the live event that I can get. But at least we have choices. Keep up the good work Mark.

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    • November 21, 2014 at 10:30 am
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      Jared and Channel Classics do a very good job at optimizing their DSD recordings by avoiding the messy intervening steps that most other labels suffer through with DSD/DXD etc. I’m with you in wanting accuracy, clarity and refinement in my recordings and the ones that I prefer listening to.

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  • December 19, 2014 at 1:14 am
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    I think if one was to take an analogue master tape, give it to the same mastering engineer and have the final master laid to both PCM and DSD machines of equal build quality, anyone would be hard pressed to tell them apart. No reason for DSD to lack air or roll off the top end, it’s just as capable at capturing high frequencies.

    Also, I don’t understand the rational of not wanting to buy a song in the DSD format that has first gone trough conversion from PCM but then think that letting the software on your PC do a conversion from DSD to PCM is better? I mean a studio grade converter will be better than consumer software I would assume, or at least equivalent. If you only have a PCM DAC, probably better to buy PCM recordings?

    DSD over PCM frames I think results in bit perfect playback though right? May be this is what your software was doing?

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    • December 19, 2014 at 3:04 pm
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      There was an AES study that tested the perceptibility of DSD 64 vs PCM 192 and the results showed no one could. You hardware…that’s another issue. People advocate for DSD because it’s “warmer and more analog like”. It’s not…so why not stick to PCM, which we know works and avoids all of the problems of DSD?

      Reply

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