6English
Since there are large variety of settings and connections possible according to applications, read
the instruction manual well to select the proper setting and connection.
1.Remove the ignition key and disconnect the negative -terminal of the battery to prevent short
circuits.
2.Set the unit according to the intended usage.
3.Connect the input and output wires of the units.
4.Connect the speaker wires.
5.Connect the power wire, power control wire and grounding wire following this order.
6.Install the unit in the car.
7.Connect the negative -terminal of the battery.
•If sound is not output normally, immediately turn power off and check connections.
•Be sure to turn the power off before changing the setting of any switch.
•If the fuse blows, check wires for shorts, then replace the fuse with one of the same rating.
•Check that no unconnected wires or connectors are touching the car body. Do not remove caps
from unconnected wires or connectors to prevent short circuits.
•Connect the speaker wires to appropriate speaker connectors separately. Sharing the negative
wire of the speaker or grounding speaker wires to the metal body of the car can cause this unit
to fail.
•After installation, check that the brake lamps, winkers, and wipers work properly.
2CAUTION

■Installation procedure

Connection
The acoustic properties of vehicle compartment tend to
cause oscillation due to resonance or unclearness of
sound due to standing waves at certain frequencies.
The band reject filter can solve the problems of
resonance or unclear sound with minimum influence on
the sound quality because it eliminates only the
frequencies causing resonance or standing waves.

■Adjustment method:

The band reject filter cuts only the limited frequencies to minimize influence on the sound
quality. Therefore, its effect cannot be obtained unless the cutoff frequencies are set
accurately to the frequencies causing resonance and standing waves. The band reject filter can
be adjusted according to what you feel through your ears, but we recommend the use of a
signal generator or a spectrum analyzer with a fine frequency measurement capability for the
adjustment.

•Adjustment using a signal generator:

Output a sine wave, vary its frequency to find the frequencies at which the vehicle compartment
resonates or volume increases (standing waves occur), and set the B.R.F. FREQUENCY control
to the position with which the resonance and standing waves disappear.

•Adjustment using a spectrum analyzer:

Output white noise (sound in which all frequencies are at a certain level), find the peak
frequency observed on the spectrum analyzer, and set the B.R.F. FREQUENCY control to the
position with which the peak observed on the spectrum analyzer disappears.
Frequency
0 dB
Band Reject Filter