Alpine R-A60F Owners Manual English - Page 11

Input Gain Adjustment Control Set the R-A75M/R-A60F input gain to the minimum position. Using a dynamic CD as a source, increase the head unit volume until the output distorts. Then, reduce the volume 1 step (or until the output is no longer distorted). Now, increase the amplifier gain until the sound from the speakers becomes distorted. Reduce the gain slightly so the sound is no longer distorted to achieve the optimum gain setting. Crossover Frequency Adjustment Knob (LP FILTER) (R-A75M only) Use this control to adjust the crossover frequency between 50 Hz to 400 Hz. Bass EQ Adjustment Knob (R-A75M only) Add a 50 Hz bass boost up to +12 dB to tune your bass response. Subsonic Filter (R-A75M only) The subsonic filter is for cutting ultra low frequencies from the input signal before being amplified. Frequencies lower than the specified frequency are attenuated at 24 dB/octave. This is desirable for several reasons: - To protect speakers too small or not capable of reproducing ultra low frequencies. - To minimize power wasted from reproducing inaudible sound. - To protect subwoofers in vented enclosures from over excursion below the tuning frequency. Speaker Input Level Switch Switch according to the Speaker input mode. a) When making a speaker input connection with RCA Extension Cables (sold separately), set to "LO". b) When making a speaker input connection with Speaker-RCA Conversion Cables (sold separately), set to "HI". Crossover Mode Selector Switch (CHANNEL-1/2) (R-A60F only) a) Set to the "OFF" position when the amplifier will be used for driving full range speakers or when using an external electronic crossover. The full frequency bandwidth will be output to the speakers with no high or low frequency attenuation. b) Set to the "HP" position when the amplifier is used to drive a tweeter/ midrange system. At this setting, Crossover Frequency Adjustment Knob ( ) provides adjustment between 50 Hz to 400 Hz. The frequencies below the crossover point will be attenuated at 12 dB/octave. NOTE: • In this case the maximum Bass EQ boost level is reduced. c) Set to the "LP" position when the amplifier is used to drive a subwoofer. At this setting, Crossover Frequency Adjustment Knob ( ) provides adjustment between 50 Hz to 400 Hz. The frequencies above the crossover point will be attenuated at 12 dB/octave. d) Set to the "HP-H" position when the amplifier is used to drive a tweeter system. At this setting, Crossover Frequency Adjustment Knob ( ) provides adjustment between 400 Hz to 6 kHz. The frequencies below the crossover point will be attenuated at 12 dB/octave. Crossover Frequency Adjustment Knob (HP/ LP FREQ.) (R-A60F only) Use this control to adjust the crossover frequency between 50 Hz to 400 Hz. Crossover Frequency Adjustment Knob (HP-H FREQ.) (R-A60F only) Use this control to adjust the crossover frequency between 400 Hz to 6 kHz. Input Channel Selector Switch (CHANNEL-3/4) (R-A60F only) a) This switch setting is for selecting either 2-channel or 4-channel input mode. When set to "1/2", signal will be copied from CH-1/2 and sent to CH-3/4, eliminating the need for Y-adapters. b) Setting this switch to "3/4" will keep both inputs, CH-1/2 and CH-3/4 independent. A 4-channel source is required for this mode. 9-EN