10
-EN
Input Gain Adjustment Control
Set the X-A90M/X-A70F/X-A90V 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 (X-A70F
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. 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. The frequencies above
the crossover point will be
attenuated at 12 dB/octave.
Crossover Frequency Adjustment Knob
(X-A70F/X-A90V only)
Use this control to adjust the crossover
frequency between 50 and 400 Hz.
Input Channel Selector Switch (CHANNEL-3/4)
(X-A70F/X-A90V 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.
Crossover Mode Selector Switch (X-A90V
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 “ON” position when the
amplifier is used to drive a tweeter/
midrange system. 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.
Input Channel Selector Switch (SUBWOOFER)
(X-A90V only)
a) When this switch is placed in the
“1+2+3+4” position, all the signals
are mixed and come out from the
subwoofer. This setting provides
signal to the subwoofer channel
when only 4 channel input is
available.
b) Setting this switch to “SUB” will
send the signal at the inputs of SUB
to subwoofer of the X-A90V.