for x = 1:24; % x has values of 1 to 24
corr(x) = 10^(3*(x-1)/(23*20)); % go up 3dB over this range
corr1(x) = corr(x);
end
for x = 25:46 % go back down for corr1 over this range
corr(x) = 1.41;
corr1(x) = corr(48-x);
end
See Figure 5.
Figure 5: The Left front left matrix
element in March of 1997. Note that the
boost as the steering moves toward
center is applied both along the lr=0 axis,
and along the left to center boundary.
Note also the reduction in level as the
steering moves to the rear.
The performance of the March circuit can be improved. The first problem is in the
behavior of the steering along the boundaries between left and center, and between right
and center. As a strong single signal pans from the left to the center, it can be seen in
figure 5 that the value of the lfl matrix element increases to a maximum half-way
between left and center. This increase in value is an unintended consequence of the
deliberate increase in level for the left and right main outputs as a center signal is added
to stereo music.
When a stereo signal is panned forward it is desirable that the left and right front outputs
should rise in level to compensate for the removal by the matrix of the correlated
component from these outputs. However the method used to increase level under these
conditions should only occur when the lr component of the inputs is minimal – that is
when there is no net left or right steering. The method chosen to implement this increase
in March of 1997 was independent of the value of lr, and resulted in an increase in level
when a strong signal panned across the boundary.
