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 thoughts on “Dynamics Trouble: Peak Limiting

  • Brian S

    Again, thanks for taking time to keep this blog alive, it keeps me thinking. Bear with me, I will get to a question. As you might remember I was a motion picture guy, 30 years behind the camera. When I left the industry digital was in its infancy. Today film is a very rare luxury. I just read an article by a very imaginative Director I got to work with. Doug Trumbull, (blade runner). It was about frame rates, and how there really is not a need for them or soon will not be. So to the question, where in the digital capture of music is there a concern for saturation?

    • Admin

      I’m not sure saturation per se relates to digital audio coding, recording or playback. Frame rates certainly can be aligned with sample rate and perhaps bit depth could be tied to color depth. But saturation is a value used in reference to intensity of color, right? The dynamic range is close.

  • Chris B

    This is perhaps a significant reason that Apple, and most of their consumers, don’t care about lossless files, let alone higher bit depths and sample rates: the majority of tracks they’re listening to are such that the benefits are negligible, or possibly even too revealing for this kind of production.

  • Accurate Dynamics have always been one of the most important aspects of music reproduction, and one that has been the least respected in high end audio circles. We threw away our high efficiency speakers of old for acoustic suspension designs in search of the ultimate flat frequency response graph, forsaking dynamics, harmonic distortion, etc.

    We need Bob Carver to bring back a modern version of his Phase Linear 1000 Auto Correlator Noise Reduction/Dynamic Range Recovery unit. Worked fairly well to restore the necessarily restricted dynamics of vinyl and reduce it’s surface noise. Something really effective could be designed today with digital tech.

    Starting about 25 years ago I had PH1000 in a system comprised of Klipsch La Scala’s driven by a VTL 100 tube monoblocks together with a pair of 7 foot tall Hsu subwoofers driven by a pair of NAD 2400THX amps running in the bridged mode and delivering tons of power to the subs.
    That’s still one of the most dynamic and “REAL” sounding systems I ever heard. Broke my heart when I had to sell the system to retire and move to a much smaller residence in Fl.
    Now THATS Rock and Roll.

  • Dave G

    Sad but true. An entire element of the vocabulary of music- dynamics- is being simply tossed out the window. No wonder so much of today’s music sucks.

  • Dave Griffin

    All the live gigs I go to are small, and as such I get as near to the stage as possible – next to it if I can – just to avoid the PA. Even if the mixing engineer’s not messing with the sound too much I prefer to get as close to the musicicans as possible to hear them, or their own amplification, and not the PA.

  • Mark, I was watching you on Home Theater Geeks and I just want to ask you directly: Don’t you believe that the Loudness War has a much more profound effect on the degradation of fidelity than the bit or sampling rate?

    • Admin

      Absolutely. The demands of the commercial music business does more to limit great sounding records than the formats, sampling rates, and encoding flavors.

  • “All of the same processes are used during live concerts, too.”
    That is a good point – and a very important too.

    Some live events are so miserable, that you hardly can stay there (unless you wear hearing protection, and already have had a couple of beers).
    I used too think, that it is because I am getting ‘old’.
    But lately I have come to more or less the same conclusion as you described above.
    The guy(s) at the mixing console(s) are going totally crazy – I wonder, why the musicians don’t notice that ;-(


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