WM8985
Pre-Production
5-BAND EQUALISER
The WM8985 has a 5-band equaliser which can be applied to either the ADC path or the DAC path.
The plots from Figure 50 to Figure 63 show the frequency responses of each filter with a sampling
frequency of 48kHz, firstly showing the different cut-off/centre frequencies with a gain of 12dB, and
secondly a sweep of the gain from -12dB to +12dB for the lowest cut-off/centre frequency of each
filter.
15
10
5
15
10
5
0
0
-5
-5
-10
-10
-15
-15
10-1
100
101
102
103
104
105
10-1
100
101
102
103
104
105
Frequency (Hz)
Frequency (Hz)
Figure 50 EQ Band 1 Low Frequency Shelf Filter Cut-offs
Figure 51 EQ Band 1 Gains for Lowest Cut-off Frequency
15
10
5
15
10
5
0
0
-5
-5
-10
-10
-15
-15
10-1
100
101
102
103
104
105
10-1
100
101
102
103
104
105
Frequency (Hz)
Frequency (Hz)
Figure 52 EQ Band 2 – Peak Filter Centre Frequencies,
EQ2BW=0
Figure 53 EQ Band 2 – Peak Filter Gains for Lowest Cut-off
Frequency, EQ2BW=0
15
10
5
0
-5
-10
-15
10-2
10-1
100
101
102
103
104
Frequency (Hz)
Figure 54 EQ Band 2 – EQ2BW=0, EQ2BW=1
PP, Rev 3.4, October 2006
112
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
