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Each channel has a 4 stage cascaded 2nd order filter. The user can set each filter coefficients (see paragraph

10). The coefficient for the Left and Right channels are common, as well as the coefficients for the surrounds.

There is also an input scaling factor for each channel which can be set with values from 0 to -1. The scaling

factor should be set to an appropriate value that will prevent the filter going into saturation.

The Static EQ filters are activated by setting Static EQ and Side Firing register (add. 70h, see section 12.12).

10.3 Surround Side Firing

Instead of the normal filters described in the previous section above, a special topology is available for the sur-

round channels:

Figure 10.

By designing appropriate filters special surround sound can be achieved for a system which its surround speak-

ers are located next to the front speakers and are rotated to the sides (see picture). The Side firing topology is

enabled by setting Static EQ and Side Firing register (add. 70h, see section 12.12).

Figure 11. Speaker System with Side-Firing positioning

Scale in

Factor

bi-quad0

bi-quad1

+

and Phase

Invering

+

Left Surround

Input

Left Surround

Output

bi-quad2

bi-quad3

Scale in

Factor

bi-quad0

bi-quad1

Right Surround

Input

bi-quad2

bi-quad3

Right Surround

Output