Chapter 6. Sound Settings
49
vocal range are unaffected, since the human ear picks these up very easily at any sound
level. It is of course also possible to use this effect at higher volumes for enhanced bass
and treble.
6.8. Auto Volume
Auto volume is a feature that automatically lowers the volume on loud parts, and then
slowly restores the volume to the previous level over a time interval. This setting allows
this time interval to be configured. Short values like 20 ms are useful for ensuring a
constant volume for in-car use and other applications where background noise makes a
constant loudness desirable. A longer timeout means that the change in volume back
to the previous level will be smoother, so there will be fewer sharp changes in volume
level.
6.9. Super Bass
This setting changes the threshold at which bass frequencies are affected by the
Loud-
ness
setting, making the sound of drums and bass guitar louder in comparison to the
rest of the sound. This setting only has an effect if
Loudness
is set to a value larger
than 0 dB.
6.10. MDB – Micronas Dynamic Bass
The rest of the parameters in this menu relate to the Micronas Dynamic Bass (MDB)
function. MDB is designed to enable the user to hear bass notes that the headphones
and/or speakers are not capable of reproducing. Every tone has a fundamental frequency
(the “main tone”) and also several harmonics, which are related to that tone. The human
brain has a mechanism whereby it can actually infer the presence of bass notes from the
higher harmonics that they would generate.
The practical upshot of this is that MDB produces a more authentic sounding bass
by tricking the brain into believing it is hearing tones that the headphones or speakers
are not capable of reproducing.
The MDB parameters are as follows:
MDB enable.
This turns the MDB feature on or off. For many users this will be the only
setting they need, since Rockbox picks sensible defaults for the other parameters.
MDB is turned off by default.
MDB strength.
How loud the harmonics generated by MDB will be.
MDB Harmonics.
The percentage of the low notes that is converted into harmonics. If
low notes are causing speaker distortion, this can be set to 100% to eliminate the
fundamental completely and only produce harmonics in the signal. If set to 0%
this is the same as turning the MDB feature off.
The Rockbox manual
(version 3.13)
Archos Recorder V2/FM
