Dr. AIX's POSTS — 26 December 2014

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I’ve had a revelation. Thanks to a comment by a reader, I’ve discovered that the Meyer and Moran research and AES paper did actually produce something meaningful. It certainly wasn’t what they thought they established (that high-resolution audio and a downconverted CD spec version were audibly indistinguishable). What Meyer and Moran demonstrated in 2007 was that an analog tape transferred to a DSD 64 SACD format disc is indistinguishable from a CD resolution version of the same thing. And it turns out that this is important…and not good news for DSD.

Remember the list of products that were used during the Meyer and Moran project? You can take a look at it here. Every product listed…except one…is an SACD using DSD at 2.8224 MHz. And substantially more than half of them were original analog recordings transferred to DSD digital. The rest were sent through PCM systems to mix, master, and release on SACD.

And remember that SACD using DSD 64 has no more frequency range than a CD. And commercial recordings on analog tape have no more dynamic range than a CD.

This is the basis of my contention that the source materials used in the study were not real high-resolution recordings. They were standard definition sources packaged as DSD. The fidelity of these recordings is dependent on the production techniques used during the original sessions. The Pink Floyd “Dark Side of the Moon” was recorded on an analog 24-track tape deck, mixed to analog tape or PCM digital and then converted to DSD in both stereo and surround. The dynamic range of DSOTM and the others doesn’t eclipse that of a compact disc…nor does the frequency response. In fact, the fidelity of most of the content used in the study is standard definition.

The question is then, what was compared in the Meyer and Moran study? In fact, their results showed that members of their society could not perceive audible differences between a standard resolution SACD (DSD 64) recording of an analog source (or even the new “native DSD tracks) and a CD rendition of the same track. The Meyer and Moran result supports another study I wrote about recently that compared PCM vs. DSD. In that study (also an AES paper), the respondents couldn’t tell the DSD from the PCM.

The belief that DSD is somehow more “analog sounding”, “warmer”, or “more musical” than a PCM version is self delusion and marketing spin used by manufacturers of equipment and download vendors that want you to buy their stuff. It’s as simple as that.

Here’s the bottom line. A standard definition recording made using analog tape (stereo or multichannel) will always be a standard definition recording…it cannot meet or exceed the capabilities of human hearing. Our goal as audio enthusiasts is to get access to the “best” version of our favorite recordings…regardless of format or resolution. If properly transferred to DSD or PCM, the original recording will captured with all of its original fidelity…all of its standard definition fidelity. If you play a high-resolution transfer and compare it to a standard resolution transfer (SACD or CD spec), research has shown that individuals or varying skills and backgrounds cannot tell them apart. Thank you Meyer and Moran for establishing this fact. Pretend as they might, makers of digital equipment using ever-higher sampling rates are not able to improve on the fidelity of these transferred masters.

However, the question of whether music listeners can distinguish between real high-resolution recordings (those originally made using high-resolution capable equipment) and CD spec tracks or even great quality MP3 files is yet to be determined in a rigorous study despite what so-called experts would have you believe. The evidence seems to be on the side of sample rates at 96 or 192 kHz but these are only recent studies and will need to be duplicated.

As I’ve stated previously, I don’t really care whether people can tell the difference between CDs and my HD-Audio files…I know that the fidelity is better at 96 kHz/24-bits than at 44.1 kHz/16-bits. I also believe that someday…hopefully soon…there will be definitive proof.

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I’m still looking to raise the $3700 needed to fund a booth at the 2015 International CES. I’ve received some very generous contributions but still need to raise additional funds (I’ve received about $3500 so far). Please consider contributing any amount. I write these posts everyday in the hopes that readers will benefit from my network, knowledge and experience. I hope you consider them worth a few dollars. You can get additional information at my post of December 2, 2014. Thanks.

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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.

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