Cadillac 1995 sedan deville Owner's Manual page 184

.
The Lower Knob
Setting
the Torte
BASS: The slide control increases
01-
decreases the bass response tons.
Moving the control to thc right increases bass while moving it to the left
decreases it.
TREB: The slide control increases or decrcases the treble response tone.
Moving the control to the right increases treble while moving to the left
decreases it.