Mercury 1999 Mountaineer Owner's Manual page 66

Controls and features
Bass adjust
The bass adjust control allows you
to increase or decrease the audio
system's bass output.
Press the BASS control then press:
to decrease bass output and
to increase bass output.
Treble adjust
The treble adjust control allows you
to increase or decrease the audio
system's treble output.
Press the TREB control then press:
to decrease treble output and
to increase treble output.
Speaker balance adjust
Speaker sound distribution can be
adjusted between the right and left
speakers.
66
BASS TREB
SEL
BASS TREB
SEL
BAL FADE