Trifield

{{weasel|date=September 2015}}

{{Use dmy dates|date=April 2020}}

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 development, and Michael Gerzon. 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.