Technical Articles

Unpublished Articles


Boat Anchors


Unpublished Articles Page

These are a few of my unpublished articles that I have converted to PDF format. They are all copyright James A. Moorer. Feel free to use these with appropriate referencing. They are unpublished because either I don't feel like publishing them, or they are not finished, or I don't think anybody would want to publish them. They may show up in a book that I may or may not write someday, so please respect the copyright and give credit where it is due. I do give permission to duplicate or copy these works in small quantities (and not for profit) for educational or research purposes.
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New Audio Formats: A Time of Change, and a Time of Opportunity.  This was a "White Paper" I wrote while at Sonic Solutions. I suppose it is really their property. It was written early in the development of hi-res audio of various kinds. This was an attempt to describe these developments, which were new and unknown at the time, to audio professionals with varying degrees of technical expertise.

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The Manifold Joys of Conformal Mapping: Applications to Digital Filtering in the Studio - 2nd Try.  This is an expanded version of two papers. One appeared in the Journal of the Audio Engineering Society, Volume 31, Number 11, November 1983, pp826-841. The other ("General Spectral Transformations for Digital Filters") appeared in the IEEE Transactions on Acoustics, Speech and Signal Processing, Volume ASSP-29, Number 5, October, 1981, pp1092-1094. There is a fair amount of new material added, especially on notch filter design. A number of gratuitous editorial comments have been redacted.

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Towards a Rational Basis for Multichannel Music Recording. (with Jack H. Vad) Circa 1999. This is an expanded version of the paper that was presented at the 104th AES Convention (May 1998). It is quite a bit more complete and contains more extensive discussion of rematrixing and after-the-fact repositioning. It is significant because it points out that if the original multi-track mix is produced using this methodology, it can automatically generate a stereo mix for CD mastering. Furthermore, if you sell or download the 3rd channel, you can combine that 3rd channel with the data on the CD to produce the original surround mix. And, as always, this can be matrixed into any number of speakers in any orientation.

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Extension of the Method of Spatial Harmonics to Three Dimensions.  All the stuff I did using spatial harmonics was published in 2-dimensions. This just shows the math all in 3 dimensions for completeness. Also, I switched notation from Gerzon's direction-cosine form to the more traditional Legendre function form. This makes it easier to use classical theory to figure out what is going on. It also makes it easy to use routines from, for instance, Numerical Recipies to calculate the speaker gains.

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Ultra-Directional Microphones: Part 4.  With boundless hubris, I have dared to name this paper as part four, following 3 articles by Michael Gerzon from the 1970's. This extends his theory to multiple microphone arrays with arbitrary directionality and flat frequency response. This is the wierdest paper I have ever written, in that it describes an invention that may not ever be built in my lifetime.