Alpine R-A90S Owners Manual - Page 10

SWITCH SETTINGS • Before switching each Selector Switch, turn off the power and insert a small screwdriver, etc., perpendicularly to the Switch. (Front Side) Cross FREQ Use th freque Cross FREQ Use th freque Input Input Gain Adjustment Control Set the R-A90S 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 Mode Selector Switch (CHANNEL-1/2) 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. (Rear Side) 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 "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. Cross (CHAN 8-EN ALPINE R-A90S 68-35792Z94-A (EN/FR/ES)