C
HAPTER
6. S
OUND
S
ETTINGS
43
fundamental completely and only produce harmonics in the signal. If set to 0%
this is the same as turning the MDB feature off.
MDB Centre Frequency:
The cutoff frequency of your headphones or speakers. This
is usually given in the specification for the headphones/speakers.
MDB shape:
It is recommended that this parameter be set to 1.5 times the centre fre-
quency.
This is the frequency up to which harmonics are generated. Some of the lower
fundamentals near the cut-off range will have their lower harmonics cut, since
they will be below the range of the speakers. Fundamentals between the cut-
off frequency and the lower frequency will have their harmonics proportionally
boosted to compensate and restore the ‘loudness’ of these notes.
For most users, the defaults should provide an improvement in sound quality
and can be safely left as they are. For reference, the defaults Rockbox uses are:
Setting
Value
MDB Strength
50dB
MDB Harmonics
48%
MDB Centre Frequency
60Hz
MDB Shape
90Hz
T
HE
R
OCKBOX MANUAL
A
RCHOS
O
NDIO