Pioneer GM-X424 Service Manual - Page 17

17 Gain Control Adjusting the gain controls A and B will help match the output of the car stereo to the Pioneer amplifier. Normally, set the switch to the "NORMAL" position. If the output is low even when the volume of the car stereo is turned up, turn these controls clockwise. If there is distortion when the volume of the car stereo is turned up, turn these controls counter-clockwise. • If you only use one input plug, set the gain controls for speaker outputs A and B to the same position. • Set the gain control to "NORMAL" when this amplifier is connected to a Pioneer car stereo with RCA output jacks. If the sound is too low or distorts, adjust the gain control. RCA Input Select Switch For two-channel input, slide this switch to the left. For four-channel input, slide this switch to the right. Speaker Out A: LPF (Low-Pass Filter)/HPF (High-Pass Filter) Select Switch Set the LPF/HPF select switch as follows according to the type of the speaker that is connected to the speaker output connector and the car stereo system: LPF/HPF Select Switch LPF (left) OFF (center) HPF (right) Audio frequency range to be output Very-low-frequency range Full range Low-frequency range to high-frequency range Speaker Type Sub-woofer Full range Tweeter Remarks Connect a sub-woofer. If you want to cut the verylow-frequency range because it is not necessary for the speaker you use. Power Indicator The power indicator lights when the power is switched on. BFC (Beat Frequency Control) Switch (ES and EW models) If you hear a beat while listening to an AM broadcast with your car stereo, change the BFC switch using a small screwdriver. Speaker Out B: HPF (High-Pass Filter) Select Switch Set the HPF select switch as follows according to the car stereo system and the type of the speaker that is connected to the speaker output: HPF Select Switch OFF (left) HPF (right) Audio frequency range to be output Full range Low-frequency range to high-frequency range Speaker Type Full range Tweeter Remarks If you want to cut the verylow-frequency range because it is not necessary for the speaker you use. Speaker Out A: Bass Boost Level Control Bass boost level control can boost the level around the frequency selected by the bass boost frequency control to 0 to 12 dB. Speaker Out A: Bass Boost Frequency Control (GM-X424) You can select a bass boost frequency from 40 to 120 Hz with the bass boost control. • Bass Boost Level Control, Bass Boost Frequency Control can be adjusted only when the LPF/HPF select switch is set to a position other than HPF. Fig. 8 8. OPERATIONS AND SPECIFICATIONS - SETTING THE UNIT GM-X424, GM-X324