Bass and Treble Controls (Bass) (Treb)

This control is a 270 degree rotary pop-out/pull knob with the center detent that is shared between BASS and TREB. Use these controls in order to adjust the system's audio frequency response. Operate the BASS function by first pressing and then releasing the knob to the out position. The BASS function affects only the lower audio frequencies. The BASS function has a center frequency of 60 Hz. In order to operate the TREB function, refer to the following steps:
1. Press and release the knob to the out position.
2. Pull the knob to the fully extended position. The TREB function affects the high audio frequencies. The TREB function has a center frequency of 10 kHz.

The center position of a given control indicates the flat response over that particular frequency range. Moving a control to the right of center position produces boost. Moving a control to the left of center position produces a cut in frequency range related to that control. All units incorporate a loudness feature that automatically increases bass bias at low listening levels.

On the UPO model with auto tone control (ATC), any adjustment of the controls activates the MANUAL tone control (ATC) mode. The adjustment of the controls establishes the MANUAL ATC mode as default. The MANUAL tone mode displays on the ATC models. The Bass and Treble changes do not affect the radio display on non-ATC models. Press the knob back into the stored position when not in use.