Kenwood C-707I Instruction Manual page 64

EX.BASS
The EX.BASS setting can be used to enhance the bass range.
64
C-707I
Enhancing the Bass Range
1 1
Press the [EX.BASS] key.
The setting changes as shown below each time you press the [EX.BASS] key.
Turning on EX.BASS disables the SOUND function automatically.
"EX.BASS" appears.
"EX.BASS" disappears.