Ambisonic Surround Sound, 'Heterodyne Brainwash' in UHJ

Показать описание

Once-Upon-A-Time,
Back in the dim and distant days of 2005 and gainful employment, people used to send me to places on aeroplanes to do things. Occasionally one would sit on the tarmac with the engines idling for a while, and they would come close to the same RPM and create a slowly changing heterodyne beat. "Wouldn't it be nice to create a highly avanty-gardey piece of sound (music? Art!) out of several sinewaves slowly changing in pitch, to deliberately create a lot of heterodyne effects," I mused. "Even better, what if they were rotated around the Ambisonic soundstage at a rate exactly linked to their change in pitch - which would itself be controlled by a sine wave?"
Well, in 2006 I did this. Six sine tones start at the 12 O'Clock position and change pitch while rotating anti-clockwise at different rates. One tone does just one cycle over the nine minutes, starting at A440, rising to 1760Hz and down to 110Hz before returning to 440Hz and 12 O'Clock. The five other tones do the same thing, but cycle at double the rate per tone. If you can't stroke an electronic music beard to that, then you're not trying hard enough.
Teccy Notes:

One MIDI controlled voltage was used to create the voltage control for the pitch. A second cosine output was also created and these were wangled with some voltage summing to create suitable voltage controls for the Ambisonic Panner:

Each tone was recorded in multi-tracked B-format one at a time. The exported B-format file was digitally encoded to UHJ for you to listen in stereo, or use with your UHJ decoder to listen in surround. If you can get this video to play over your home system like a movie and enable normal 1970s analog Dolby stereo (which should be in there operating as a hierachical default anyway) then the vectors are vaguely in the same directions and you should be able to hear the sounds panning around quite well. Hopefully the 192kbps AAC in the video hasn't messed-up the phase based surround encoding too much.

Visual stimulation is provided here by sending the X and Y components of the B-format audio file to my trusty Kikusui oscilloscope in X-Y mode, with the X channel connected to X on the 'scope and Y connected to Y, naturally. Close observers will note that the trace starts and ends with the trace vertical. Yes. Because X is front-back in B-format, as per the ISO 3-D space mathematical representation standard for things like flight simulators.

This audio once found the light of day on a self-published CD-R and even made it out into the wilds of the internet. Here is a link to the original page: