Surround (ambisonic) mixing in LE

[McGriffy]

In response to a request on another thread I have written up a short web page to explain how I do surround mixing in ProTools LE. I am using a technique called ambisonic recording and what I've done is build an ambisonic transcoder in PTLE. This lets you use the normal stereo sliders to create a full surround mix. An example session (with no audio, thus small) is available for download. See
http://mcgriffy.com/audio/ambisonic/transcoder/

[Zeus]

Great! I have to check it out. [img]images/icons/cool.gif[/img]

Z

[sandman]

thanx for that !
i'll check it also !
but one think i wanted to ask for long time , will i able to add a surround track(song) to a normal CD (ie , bonus track . .)
i thought all the time that multi channel music avalible only in DVD or SCD(?)

thanx again

[McGriffy]

Yes, it is possible to put surround material on a redbook CD. Dolby Pro Logic or any of it's older variations are matrix formats, i.e. are designed to be transmitted in two normal channels. The same is true of a format called UHJ, which is a way to matrix an ambisonic source into two channels. Similar ideas - you take the extra channels and add them out of phase in different directions to L & R then you can extract them with phase shifts, sums, and differences. Tha advantage of matrix formats is that they also work if just listed to in stereo. Most VHS movies are apparently in Pro Logis these days, though I don't have a home theater system so I can't say for sure. Using a matrix format your whole album could be in surround for those with decoders but still fine for stereo (and mono) folk. Wendy Carlos Switched on Bach 2000 is done in Pro Logic and the Cowboy Junkies Trinity Session is in UHJ as a couple of examples.

The other thing you could do put DTS on a CD. This gives you real 5.1 discrete surround. The trouble is that it is just noise at -12dBFS for anyone without a decoder. I would hesitate to put such a track at the end of a normal CD. Then again, you could just put a minute or two of silence in between as a warning. Anyone who has left the CD playing through minutes of silence probably needs to be woken up. DTS encoding software is available as a Mac only plugin from Kind-of-Loud or as a stand alone PC product from Minnetonka Audio. The CD rate product from Minnetonka runs about $500.

DMcG