WM8945
Production Data
To determine the characteristics of the loudspeaker in an application, a test signal is applied to the
target application. A reference microphone is positioned in the normal acoustic path of the
loudspeaker, and the received signal is analysed to determine how accurately the loudspeaker has
reproduced the test signal.
5-BAND EQ
ReTuneTM
5-band EQ
Signal Enhancement Block 2 (SE2)
The 5-band EQ is part of the SE2 block. This function allows 5 frequency bands to be controlled. The
upper and lower frequency bands are controlled by low-pass and high-pass filters respectively. The
middle three frequency bands are notch filters. The cut-off / centre frequency of each filter is
programmable, and up to 12dB gain or attenuation can be selected in each case. The 5-band EQ is
enabled using the SE2_5BEQ_L_ENA register bit defined in Table 14. For the derivation of the other
associated registers, refer to the WISCE software.
Typical applications of the 5-band EQ include the selection of user-preferences for different music
types, such as ‘rock’, ‘dance’ or ‘classical’ EQ profiles.
DYNAMIC RANGE CONTROL (DRC)
DRC
Signal Enhancement Block 3 (SE3)
The Dynamic Range Control (DRC) forms the SE3 block. The DRC provides a range of compression,
limiting and noise gate functions to support optimum configuration for recording or playback modes.
The DRC is configured using the control fields in registers R29 to R35 – see “Dynamic Range
Control”.
SIGNAL ENHANCEMENT REGISTER CONTROLS
The SE1 ‘enable’ bits are described in Table 13. Note that other control fields must also be
determined and written to the WM8945 using WISCE™ or other tools. The registers described below
only allow the sub-blocks of SE1 to be enabled or disabled.
Note that it is not recommended to access these control fields unless appropriate values have been
written to the associated bits in registers R65 to R95.
PD, May 2011, Rev 4.1
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