The Trifield process is a form of audio rendering in which a
conventional two-channel signal is decoded (using
Ambisonic
principles) to an additional number of loudspeakers, typically three in
the form of a Left-Centre-Right front stage. The technique provides
significant additional image stability, especially when the listener
is moving or off-axis.
It was developed by Dr Geoffrey Barton, a major figure in the "second
wave" of original
Ambisonics
Ambisonics is a ''full-sphere'' surround sound format: in addition to the horizontal plane, it covers sound sources above and below the listener.
Unlike some other multichannel surround formats, its transmission channels do not carry speaker si ...
development, and
Michael Gerzon
Michael Anthony Gerzon (4 December 1945 – 6 May 1996) is probably best known for his work on Ambisonics and for his work on digital audio. He also made a large number of recordings, many in the field of free improvisation in which he had a par ...
. It
should not be confused with a Yamaha system with a similar name.
Trifield also has applications in conventional surround mixing. There are
several problems involved in mixing with an additional centre front channel
for many engineers. The channel itself was originally designed for dialogue
in matrix cinema surround systems and does not have a direct application in
music mixing, where a 2-speaker stereo stage is generally, and traditionally,
employed.
Many studio engineers with a background in conventional stereo music mixing
find that simple panning of a source to the centre-front (CF) channel makes
it fail to blend in with the stereo mix. However, if the CF channel is left
silent, consumers may believe there is a fault with the disc or with their
equipment. A way around this problem is offered by Trifield. The processor
typically takes a 2-channel L-R signal and renders it for L-C-R, and no
signals are sent to the CF except for those generated by the Trifield
processor. Not only does CF content now blend with the mix: in addition,
the resulting soundstage is more stable and listener-position independent,
while the listener can confirm that something is actually emerging from
their centre-front loudspeaker.
See also
*
Ambisonics
Ambisonics is a ''full-sphere'' surround sound format: in addition to the horizontal plane, it covers sound sources above and below the listener.
Unlike some other multichannel surround formats, its transmission channels do not carry speaker si ...
*
Meridian Audio, Ltd., who include the technique in their surround processors
*
Stereophonic sound
Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration ...
Further reading
*
External links
Trifield Productions who own the patent for the technique
AGM Digital Arts GmbH a licensed manufacturer of both hardware and software implementations (called TSS and ESsEX)
* (An article discussing the Trifield technique.)
Sound production technology
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