User Manual
33
V 1.1
2022-09-12
User manual for MERUS™ audio amplifier configurato
r
MA2304DNS/MA2304PNS
DSP audio blocks
Low shelf and high shelf filters
A shelf filter boosts or cuts the magnitude below or above a frequency band. In the case of a low shelf, the lower
frequency band is boosted/cut while, in the case of a high shelf, the higher frequency band is boosted/cut.
The
“
shelf filters
”
have two controls: “frequency” and “gain”
:
Table 8
Shelf filter controls
Control name
Description
Min.
Default
Max.
Unit
Frequency
The frequency (f
0
) in which the
amplitude is half the gain difference
between the boosted and unboosted
region (in dB)
10
1000
F
s
/2
Hz
Gain
The peak amplitude of the filter
-48
1
24
dB
An example family of shelf filter curves with varying gain settings, f
L
= 300 Hz, f
H
= 10 kHz, is shown below:
Figure 45
Shelf filters with -12, -6, +6 and +12 dB gain, f
L
= 300 Hz and f
H
= 10 kHz
