Subaru 2005 Forester Owner's Manual page 221

Audio
Display Control mode
BASS Bass control
MIDDLE Midrange control
TREBLE Treble control
FADER Fader control
BALANCE Balance control
VOLUME Volume control
5-18
Turn counterclockwise
For less bass sound
For less midrange sound
For less treble sound
To increase rear speaker volume and
decrease front speaker volume
To increase left speaker volume and
decrease right speaker volume
For less volume
HS5014BA
Turn clockwise
For more bass sound
For more midrange sound
For more treble sound
To increase front speaker volume and
decrease rear speaker volume
To increase right speaker volume and
decrease left speaker volume
For more volume