In this paper we contrast the several different versions of the matrix elements. The
earliest are elements from our 1989 patent. These elements were used in our first
surround processor, and are identical to the elements of a standard surround processor in
the left, center, and right channels. In our design the surround channel is treated
symmetrically to the center channel. In the standard (Dolby) decoder the surround
channel is treated differently, and this issue will be discussed at length later in the paper.
The elements presented here are not always correctly scaled. In general they are
presented so the unsteered value of the of the non-zero matrix elements are for any given
channel is one. In practice the elements are usually scaled so the maximum value of each
element is one or less. In any case, in a final product the scaling of the elements is
additionally varied in the calibration procedure. The matrix elements presented here
should be assumed be scalable by appropriate constants.
The left front matrix elements in our ’89 patent
Assume cs and lr are the steering directions in degrees in the center/surround and
left/right axis respectively.
In the ’89 patent the equations for the front matrix elements are given as:
In the left front quadrant
LFL = 1 – 0.5*G(cs) +.41*G(lr)
LFR = -0.5*G(cs)
In the right front quadrant
LFL = 1-0.5*G(cs)
LFR = -0.5*G(cs)
In the left rear quadrant
LFL = 1-0.5*G(-cs)+.41*G(lr)
LFR = +.5*G(-cs)
In the right rear quadrant
LFL = 1-0.5*G(-cs)
