Dr. AIX's POSTS — 30 March 2016


Yesterday, I pulled a statement from a Q&A document prepared by Robert Stuart of MQA and Meridian. In response to my question about the applicability of MQA to high-resolution music and older standard-resolution formats like “analog and CD-Quality” music. My question should have stated, “analog tape” instead of “analog”. Or course, analog sound or live performances of music are “high-resolution” to those present in the venue. It struck me as a little strange to associate high-resolution and a purely acoustic event. I took his point without referencing the AES article footnote. I’m pleased that he read the post and send along the following clarification. I was confused by my poor wording of the question. I apologize for the mistake.

Here’s Bob’s email:

“Hello Mark,

I hope you are well.

‘Your question implies that analogue is not high resolution, but of course that isn’t the case.’

I noticed your post. This is one sentence out of a 1-page answer and on its own can be taken out of context!

It is self-evident that not all digital formats are perfect (e.g. MP3). Similarly, not all methods of analogue recording give high resolution. Interesting (and occasionally important) as they are, the cylinder, shellac or vinyl record (although some disagree in both cases) or cassette tape are very compromised.

By the way, my sentence was not qualified by anything to do with recording, but if we stick with recording, I would not have suggested vinyl was very high resolution, principally because since the 1950s such a release has generally been 2 generations away from the captured recording and implicitly if not actually tamed at low frequencies and boosted at highs to allow the cutter to do its job. The format is largely incapable of response beyond 20 Hz – 20 kHz.

My point was more fundamental, namely that the sound we hear is analogue (in air) and any recording method has to translate the original analogue through a carrier and back to analogue. Since the 80s we tend to use a digital channel in the middle.

If I sit 10 ft away from a live piano performance, it is an analogue path; no-one can tell me that the resolution is not high. Now, if we put up a microphone and listen to that feed (over a good monitoring system), it is still analogue and the resolution will still be high – diminished by the microphone and electronics – but still the best we can get if a recording system is interposed, be it analogue or digital. But we must remember that irrespective of the digital channel, the analogue electroacoustics at both end have to be as good or better.

In my answer in the Q&A, I was referring the reader to this open access AES paper, http://www.aes.org/e-lib/browse.cfm?elib=18046 . This was tough to write to a 1000 word limit, but in the 3rd column it has one key sentence which should have been italicised had the journal allowed: ‘Notice that we just defined High Resolution in analog and not digital terms’

Feel free to either post this comment verbatim or add it as another Q in in the Q&A.

Very Best


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About Author


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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