MAS3587F Micronas, MAS3587F Datasheet - Page 46

• Manufacturer Part Number: MAS3587F
• Description: MPEG Layer 3 Audio Encoder/Decoder
• Manufacturer: Micronas

MAS 3587F
Table 3–12: Codec control registers on I
46
Register
Address
(hex)
Micronas Dynamic Bass (MDB)
00 22
00 23
00 24
00 21
Function
MDB Effect Strength
bit[15:8]
The MDB effect strength can be adjusted in 1dB steps. A value of 40
yield a medium MDB effect.
MDB Harmonics
bit[15:8]
The MDB exploits the psychoacoustic phenomenon of the ‘missing fundamen-
tal by creating harmonics of the frequencies below the center frequency of the
bandpass filter (MDB_FC). This enables a loudspeaker to display frequencies
that are below its cutoff frequency. The Variable MDB_HAR describes the ratio
of the harmonics towards the original signal.
MDB Center Frequency
bit[15:8]
The MDB Center Frequency defines the center frequency of the MDB band-
pass filter (see Fig. 3–4 on page 49). The center frequency should approxi-
mately match the cutoff frequency of the loudspeakers. For high end
loudspeakers, this frequency is around 50 Hz, for low end speakers around
90 Hz
MDB Shape
bit[15:8]
With a second lowpass filter the steepness of the falling slope of the MDB
bandpass can be increased (see Fig. 3–4 on page 49). Choosing the corner
frequency of this filter close to the center frequency of the bandpass filter
(MDB_FC) results in a narrow MDB frequency range. The smaller this range,
the harder the bass sounds. The recommended value is around
1.5
MDB Switch
bit[7:2]
bit[1]
bit [0]
MDB_FC
5...30
00
7F
00
64
7F
2
3
...
30
0
1
hex
hex
hex
hex
hex
MDB off (default)
maximum MDB
no harmonics are added (default)
50% fundamentals + 50% harmonics
100% harmonics
20 Hz
30 Hz
300 Hz
corner frequency in 10-Hz steps
(range: 50...300 Hz)
reserved, must be set to zero
MDB switch
MDB off
MDB on
reserved, must be set to zero
2
C subaddress 6C
hex
hex
will
ADVANCE INFORMATION
Name
MDB_STR
MDB_HAR
MDB_FC
MDB_SHAPE
MDB_SWITCH
Micronas