dev builds
themes manual
device status forums
mailing lists
IRC bugs
dev guide

Rockbox mail archive

Subject: RE: Optimum Audio Levels
From: Stuart Tedford (
Date: 2004-06-02

Do volume levels depend on the gain (or normalisation) of your mp3s too? I
use mp3Gain to normailise my entire
collection to 89dB. So my levels are:
90% : In the Car (plugged into cassete adaptor of car stereo)
75-95% : headphones - depending on background noise levels.
85-90% : connected to home stereo equipment.


-----Original Message-----
From: BlueChip []
Sent: 02 June 2004 09:15
To: rockbox development
Subject: Optimum Audio Levels

Hey all,

I need to do a little survey to optimise the new Audio Interface...

One question :)

What is the VOLUME range you use most often?

...If you use, say, one volume in the car, and another in bed at night.
Feel free to give two answers.

Personally I use:
85-95% in walkman mode
65-75% in bed
92% in the car

Skip to the "P.S." section now!
...unless you want all the techies-only stuff.

The volume scale inside the unit is measured in dB on the scale
{MUTE, -114, -113, ..., -2, 1, 0, +1, +2, ..., +11, +12}
Where 0dB is designed to produce "Line Level"

These values are numbered {0x00, ..., 0x7F} respectively
Such that {0=Mute, 1=-115dB, ..., 0x73=0dB, ..., 0x7F=+12dB}

The Rockbox volume scale is a linear transpose of the MAS scale.
That is: Actual_Volume = Rockbox_Volume*0x7F/100

...which interestingly enough means there is no Rockbox setting for
line level and you do not have fine control where required.

I have a non-linear scaling algorithm which allows greater control
in the most used volume ranges at the cost of less control in the
unused volume ranges.

At Rockbox=60%, you are down to 0x4C which is -39dB

I currently have FULL control over -18..+12dB but I think others,
particularly the audiophiles, may require accurate control at lower levels.


PS. Good news: I just found the MAS registers to turn your Jukebox into
a mixer and/or karaoke machine - so your jukebox can remove the old vocals
and add your in place, live and with a simple mixer :)

There's even an option for "3.0" sound if anyone is interested in even more
volume - lol


Page was last modified "Jan 10 2012" The Rockbox Crew