TDA7406T

16/49

Note: The center frequency, Q, DC-mode and boost/cut can be set fully independently for each filter.

2.7 Subwoofer Application

There is one separate subwoofer output. A low-pass filter stage at this output allows the selection of three dif-

ferent frequencies: 80/120/160Hz. A high Pass Filter stage is present in the main path with selectable 90/135/

180/215Hz frequencies. Both filters, the low-pass as well as the high-pass filter can be disabled and have but-

terworth characteristics so that their cutoff frequencies are not equal but shifted by the factor 1.125 to get a flat

frequency response (see Figure 12).

Figure 12. Subwoofer Application with Lowpass @ 80/120/160Hz and HighPass @ 90/135/180Hz

1

10K

10

1K

100

Hz

-1

16

0

14

2

12

4

10

6

8

dB

dB

Hz

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

100.0

1.0K

10.0K