Dr. AIX's POSTS TECH TALK — 20 November 2013

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In looking at the various protection schemes that the music industry and the RIAA have tried over the history of physical optical discs, it’s pretty clear that they’ve been unable to stop illegal copying. No big surprise there. They way I look at it, I have to believe that there are enough audiophiles around that appreciate what I’ve tried to do with AIX Records and iTrax that they will spend money to keep me in business. I can’t spend my time worrying about the minority of quality conscious music fans that want something for nothing. It’s irritating to find my stuff on some obscure Russian blog page but what can you do.

However, it is disconcerting that those who purchase quality high-resolution tracks and have the hardware to play them back cannot do so using their preferred high-end equipment at the quality level that was intended. The problems that I’ve described over the past few days continue.

Let’s take a quick look at the Blu-ray specification as it relates to high-resolution audio in stereo and surround. BD discs support a variety of audio formats. Dolby Digital and PCM ruled the DVD-Video marketplace (DTS was relegated to “optional” status) but both HD variants of Dolby and DTS are possible for Blu-rays. They are Dolby TrueHD (which is an updated version of the format used on DVD-Audio discs…MLP or Meridian Lossless Packing) and DTS HD Master Audio. Both formats are lossless and both are capable of 192 kHz/24-bits in 8 channels…wow! It’s up to the producers of any particular disc to choose between these encoding schemes.

And there’s always high-resolution PCM, a no compromise, no compression audio format that is without question the best and most accurate method of digital recording high-resolution audio. DSD might work for you as a 20-20 kHz “flavor” but plain old PCM trumps it when accuracy and ultrasonic reproduction are important (and they should be). The Blu-ray format can handle 8-channel multichannel PCM at 48/96 kHz/24-bits or 6-channels up to 192 kHz. That’s a very big improvement from the specifications of the DVD or SACD formats.

But the copy protection people are once again involved in trying to stop illegal copying of the BD format. This time they’ve come up with the AACS or Advanced Access Content System. It’s a variant of some older schemes with encryption and keys. But there are a couple of new twists with AACS.

First, it’s mandatory. I’m not allowed to replicate BD discs that are not AACS protected. I had to pay the AACS licensing organization for permission to make BD discs in the first place (which was an initial $3K and another $500 per year) and I have to pay $.04 per replicated disc to the licensing body.

Secondly, the AACS is flexible…meaning when people hack through the current key mechanism, the folks at the AACS mother ship can remotely install an entirely new set of keys to disrupt the hackers. The new scheme is clever but ultimately it won’t matter because Blu-ray discs as a music delivery format are dead on arrival.

These are the so-called “High Fidelity Pure Audio” Blu-ray discs that were launched in the EU and have now made it to the U.S. and the Pacific Rim. I saw a news item about the launch in Korea for a “new hi-fi format”. Here’s the link: Korean Announcement for High Fidelity Pure Audio BD

Here are a couple of lines from the announcement:

“This format lets out a richer and fuller sound— and can only be played on Blu-Ray players. Looking at the technical specs pure audio uses at least a 96-kilohertz sample rate at 24-bit resolution—in translation, that means a much higher quality than a CD’s 44 kilohertz sample rate at 16-bits”

What this press piece and all of the others touting the benefits of HiFi Pure Audio BD discs is that they’re shoveling the same old masters at us once again and making us pay almost $30 for the opportunity. Stay away from this scam.

Blu-ray concerts and those BD discs with high-resolution audio AND video…like those from AIX Records…and even the few Pure Audio BD discs from 2L are valid uses of the format. But the magic for me is the 5.1 surround sound with HD video. The private performance in your media room is a major step forward. That’s why AIX Records is unique in the use of the Blu-ray format. We produce and release ultimate quality Blu-ray discs WITH multiple discrete mixes AND HD-Video of the session…who needs High Fidelity Pure Audio Blu-ray? Not me.

The AACS scheme for BD discs prevents high-resolution digital audio streams to emerge from the optical or coaxial S/P DIF outputs of the players. But we already knew that. The only way to experience the best quality audio (if it’s there in the first place) is to use the internal DACs on your machine (Oppo players have terrific DACs and are very cost effective…I’m just saying) or output the signal using the HDMI connection.

Once again, those of use interested in the best external DACs will be disappointed…for a couple of reasons. We’ll be listening to downconverted audio (48 kHz/24-bits). Or if you’re fortunate to get your hands on a DAC that has HDMI inputs…you’re going to be listening in 2-channel stereo…very old school.

If you’ve got the money, the folks at Bryston have the answer. They produce a fabulous multichannel, HDMI input, processor/preamplifier with state-of-the-art DACs called the SP-3. It’s about $8000 but as far as I’m concerned there is no better multichannel converter available at any price. In Chicago next April, I will be hooking my Oppo BD player via HDMI to the Bryston SP-3 before my high-resolution AIX recordings get to the $1,000,000 worth of amplifiers and speakers (Vitus and German Physiks).

I don’t know how I could reproduce a live music session any better!

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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.

(6) Readers Comments

  1. My current configuration takes the output from my Blu-Ray player via HDMI and inputs it to my TV (Sony KDL-52EX701). I then feed an S/P DIF optical cable from the TV output to my Receiver (Denon AVR5700) where it is processed by the on-board DACs in the receiver. Am I correct that this represents another way of defeating the AACS copy protection scheme (i.e. isn’t the TV separating the full 5.1 digital audio signal and providing that to the S/P DIF output)?

    • Doug, you haven’t actually defeated the AACS in the data stream…in fact, you’ve removed any chance of getting high-resolution audio to your Denon receiver but coming into it via S/P DIF. If you connected the HDMI to your Denon and then connected the HDMI out of your Denon to the TV you would be better off.

  2. I understand that was your point about S/P DIF, but this Denon does not have HDMI inputs. BUT, my point was that the Denon appears to be recognizing and decoding the surround digital signals, illuminating the Dolby DTS indicators for each channel ONLY when 5.1 tracks are playing. Are you saying that this audio stream has been down converted to 48 kHz/24-bits or worse by the Sony TV?

    Thanks,
    Doug

  3. Went back and did some additional reading and answered my own question. Yes indeed, S/P DIF can carry compressed lossy surround, but only two channels of uncompressed PCM. I was planning an upgrade for that Denon – looks like I have much to look forward to!

    • Looks like a request for Santa?

  4. And I have been a good boy too!

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