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.

3 thoughts on “Hearing SHARP in Hi-Res Wireless

  • philmagnotta

    Hi Mark:
    In Saturday’s blog, you mentioned, ” People heard crystal clear highs and real world dynamic range”.
    I’d like to comment on dynamic range- real world or otherwise.
    As you know, well designed electronic record/reproduce systems: mics (further comment on this) and their preamps, mixing console preamp/output amp stages, A-to-D/D-to-A and power amps, etc. all surpass speaker systems-at least as far as may be possible in available off the shelf systems or that I’m aware of.
    Its true that speakers exist that can generate a whisper all the way up-to more than 120 dB. If we measure speaker output as we do, the aforementioned electronics, there is more to going from soft to loud than level.
    In amplification circuits, how we get there is equally important, such as impulse response and linearity. Good electronics can produce square wave signatures that show proper tracking of impulse with varying start and stop durations, their rise and fall accuracy and degrees of phase shift. Also, that excellent performance must encompass this ability at many different levels and frequencies across the desired range.
    If we take out the room anomaly and measure the best drivers available under anechoic conditions: straight driver test, filtered passively/electronically or multi-driver systems- passive or active, etc., we see that the actual output response would show that even average amplification circuits are far more accurate and that’s not even considering distortion performance.
    Assuming that even precision mics are akin to speaker driver behavior, in that a diaphragm/membrane transducer must be subject to same conditions more or less so, if we omit recordings with mics., we’re still left with the speaker system issue.
    Thus, the speaker system is still far off from producing accurate transmission of audio electronic information.
    Even though all of the above may be a given, what has your research revealed that show attempts to improve what we use to actually hear audio production besides JBL’s new highly acclaimed system? Even in that design, JBL is still subject to the physical laws of such systems.
    Benchmark Media’s new power amp states that their new design removes the last bottle-neck in the audio chain for signal-to-noise and dynamic range performance (my translation). John Siau definitely understands audio circuitry and I hope that someday he may be able to bring to market the real last true bottle-neck in the audio chain or at least be part of a team with other researchers- as was done with THX and the new Benchmark amp. BTW, it seems natural that you would be auditioning their new amp!
    As a final note, its interesting considering all of the above, that speakers systems do satisfy us enough in order to provide a workable audio industry so, I’m going to make an assumption based on many years of audio/music research, experience and as a violinist, that if it were possible to produce an air motion transducer (speaker system) that is as accurate in acoustic space as the best electronics, it might prove to be very disappointing. That may seem odd but, until proven otherwise, a perfect air motion transducer, as determined and measured to meet/exceed the same specs as audio circuits, would reveal the true nature of our accurate audio signals as surprising and not necessarily good or without further comment as to what might be necessary for more realistic performance. This is surely debatable.
    Looking forward to your comments please and thanks for your daily blog.

    • Admin

      Thanks for the considerable contribution. I think you’re right…the last great link in the chain of accurate audio recording and reproduction is the speaker. Getting the complete range of frequencies to match the signals captured by the microphones and all of the timing aspects (transients etc) bring the fidelity of a system ever closer to the real event. However, it’s also important to realize that recreating a live musical event is not a goal held by many musicians and producers. Last evening, I set up a session in my room and the R&B producers simply wanted loudness and lot of low bass. It was interesting that they chose to listen to their tracks using my JBL film system and Profunder sub.

      • Dave Griffin

        Mark wrote: “..it’s also important to realize that recreating a live musical event is not a goal held by many musicians and producers”.

        And yet many component reviewers use off-the-shelf music to determine how good the component under scrutiny is. Of course, unless the potential purchaser creates their own recordings, off-the-shelf music is all that component will ever see.

        I think the problem with loudspeakers is (a) their directionality and (b) drive unit mass (and I suppose (c) distortion due to differing break-up modes, crossover etc); I noted a few weeks ago that one respondent wrote how he could always easily differentiate between recorded and live music when walking by a room emanating music. Given that he would be well off the speakers axis, this is hardly surprising. If and when we get a truly point source speaker (the Quad Electrostatic has a stab at being a point source, but is still highly directional) the is it live or is it recorded debate might get a lot more interesting (with suitable material, of course).


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