Dr. AIX's POSTS — 29 May 2015

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Master Quality Authenticated (MQA) is the latest darling of the audiophile press and (even mainstream) music industry. There are been a number of articles and web posts that go through the technology. Some months ago, I addressed the clever bandwidth reduction techniques that the developers devised to bring large data rates below those of CDs. That’s the core of MQA. It is a methodology of reducing the footprint and transmission pipeline requirements of PCM encoded audio files larger than a compact disc. And it does this without abandoning the legacy formats…it is backwards compatible. If you don’t have an MQA enabled piece of hardware, encoded discs will function at normal resolutions. Brilliant.

It doesn’t alter the fidelity of the original source, which is likely to be an older standard definition analog tape transferred to a high-resolution bit bucket. MQA will allow standard definition recordings that use too much bandwidth to be streamed in smaller packets. That’s a great move forward for getting real high-resolution audio into the streaming world. I’ll be talking about that in my keynote address today at the Newport Show.

Here’s the transcription of the presentation text I peeled from the Meridian video at the recent Munich Show. I think it’s important to parse this communication and do a reality check on some of the points.

“MQA stands for Master Quality Authenticated. It means that in the studio, the artist can be sitting there in the studio with the producer and they can say, “this is my final master, this is my art, this is what I want everyone to hear. In fact, I want them to hear this exact sound. So now you’ve got a master quality file in a convenient, easy to use format that it is authentic and everyone knows. It takes away the arguments that have been going on over and over about the provenance of the files. Where did it come from? Was it upsampled? Is this the one that they really worked on? It now guarantees that you as the music lover, the music fan, are getting the exact file.”

So you’re an artist or producer sitting in the studio (mixing or mastering?) expressing satisfaction at the sound coming from the expensive and tuned monitor speakers. That’s master quality. It is most likely not high-resolution audio because virtually all commercial productions are recorded at 48 kHz/24-bits…AND heavily processed so that the dynamics are almost completely flat. “This is my final master, this is my art, this is what I want everyone to hear.” OK, fine. I call that the “master source”…and so should those pushing the misleading definition of high-resolution audio.

The studio will prepare the final transfer to the formats required by the label…44.1 kHz/16-bit PCM for the CD and 96 kHz/24-bits for “Mastered for iTunes” (which requires a sample rate conversion step). Then the 96 kHz/24-bit master is encoded into MQA from the new PCM transfer…note the new file is full of zeros. There is no data above the Nyquist frequency of the original 48 kHz file.

You can have the PCM original file or the MQA file. Which would your prefer? Maybe you want the upconverted version.

Most new record productions are not being done in high-resolution audio.

The tracks that everyone wants in “high-resolution” are the older analog tapes that will be newly transferred from the analog tapes to new PCM high-res buckets. This should be done using the best analog tape machines, the best electronics, and without any modifications or remastering. This is the archive.

There are some frequencies above 22.050 kHz that can be captured from an analog tape but the dynamic range never rises above 10-12 bits…usually much less. Capturing these new transfers at 96/192 kHz/24-bit PCM with great converters is the right thing to do. If TIDAL or someone else wants to stream these “master quality” files, then MQA makes it possible. The 4000 kbps becomes 1000 kbps for a file that isn’t high-resolution but does sound exactly like the original master.

The arguments about provenance will continue because the master source production sequence is still unknown. There are still no guarantees that you’re getting something better than what we had previously or that the transfer was done from the right “master”. It simply means that you haven’t lost anything in the conversion…AD and DA.

Let’s not elevate the MQA technology to something that it’s not. I applaud Robert and Peter on a remarkable invention. But it’s not going to create “holograms of instrumental sound apart from the hiss and room ambiance”.

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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.

(10) Readers Comments

  1. How much REAL-HD ablums are currently available? Answer: Not a lot. Why??? Answer: The big labels are not interested in creating something new and want to make money the easy way but just re-releasing old stuff in newer shinier formats: LPCM, DSD, DXD, BLU-RAY AUDIO, SACD, DVD-A, super hires mp3, etc,etc.

    There are probably only about 5 small labels actually doing Hi-Res.. (I’m guessing here). Aix is probably the only one with a decent size catalog.
    So Mr. Waldrep, my question for you is, How much time are you spending cranking out REAL-HD albums?
    For the rest of 2015, how many more releases can we expect from AIX? What about 2016?

    • Not very many…my estimate is around 2000. AIX has around 100 titles, 2L has many more, Harmonia Mundi, MA, Telar etc. Unfortunately, it’s very expensive to create new projects complete with high-resolution video, which I produce in addition to the high-resolution audio tracks. I’m trying to get a few new ones out this year and maybe a few next year. But it is difficult.

  2. Hi Mark, I have two questions, and you may have answered these at some previous time. I’ve only been reading your newsletter for a month or so. I find it very informative.

    1 – Will you need a dac that decodes MQA to get its benefits?

    2 – You have been talking about upsampling in the studio. There are a number of dacs on the market that offer the option or automatically upsample CDs, files, to 24/192, is there any audible benefit to those that do? From reading you, I gather there will not be any expanded data, but does it subjectively improve the sound?

    Thanks for all the knowledge you share.
    Jeff

    • Yes, the MQA algorithm will have to be part of the DAC or digital signal path.

      Upsampling makes the filtering easier and better…but it does not improve the fidelity in any meaningful way.

  3. If your keynote includes telling the truth the MQA doesn’t improve sound quality as allthe golden ears are reporting, better bring your sword fighting shield. Their gonna try to stone you.

    • I did share my thoughts on MQA. Read today’s post for a full report.

  4. Thank you Mark for the open-minded explanation of current studio practice relative to MQA. As for the 24/48 standard, most newer films are 24/96, and I would think that some studios use that rate while others use 24/48. Since they decimate just fine, no sweat.

    Clearly, we are not at a standardized point yet. Wouldn’t it be nice if it was a 24/96 world? And I’ve always wondered why 176.4 was not the target as it decimates with CD. 48khz was originally the DAT sampling frequency, if I remember correctly.

    I do appreciate your acknowledgement of the Pono player as sounding excellent. Again, it transports John Atkinson and he is a fairly audio-critical gent to say the least. He took the opportunity to strongly re-state in print this month his conclusion that the Pono is sonically special, and a very good value compared to such as A&K. Maybe the small display is Neil Young’s way of reminding us that staring at tiny tv screens is not part of the listening experience, and prevents attaining the maximum rewards .Thank You.

    • I used to be a production sound mixer (in addition to the stint as a mastering engineer) and I have a former student that runs a location sound business. The standard for film production is 48 kHz/24-bit PCM. The post production process my include 96 kH/24-bit output but the fidelity doesn’t take advantage of the higher specs.

      If thing settled on 96 kHz/24-bit PCM, I’d be happy but audiophile companies would keep claiming that higher is better.

      The Pono is a very nice digital playback device as far as portable players go…it can’t and doesn’t compete with a nice home rig.

      • …but you can’t go running on the beach with your Benchmark…

        • Actually, right now I can’t go running at all. Somehow my left knee is a little swollen…it’s always something.

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