Pioneer gm-a6604: Setting the unit

Black plate (4,1)

Section

02

Setting the unit

frequency. OFF outputs the entire fre-

What’s what

quency range.

GM-A6604

2 GAIN (gain) control

Front side

Adjusting gain controls CHANNEL A (chan-

nel A) and CHANNEL B (channel B) helps

align the car stereo output to the Pioneer

amplifier. Default setting is the NORMAL

position.

If output remains low, even when the car

stereo volume is turned up, turn controls to

Rear side

lower level. If distortion occurs when the car

stereo volume is turned up, turn these con-

trols to higher level.

! If using only one input plug, set the gain

controls for speaker outputs A and B to

the same position.

! For use with an RCA equipped car stereo

GM-A4604

(standard output of 500 mV), set to the

Front side

NORMAL position. For use with an RCA

equipped Pioneer car stereo, with maxi-

mum output of 4 V or more, adjust level

to match that of the car stereo output.

! For use with an RCA equipped car stereo

with output of 4 V, set to the HIGH posi-

tion.

Rear side

3 INPUT SELECT (input select) switch

Select 2CH for two-channel input and 4CH

for four–channel input.

! You can select input select only for con-

nections when using the RCA input jack.

For connections when using the speaker

To adjust the switch, use a flathead screwdri-

input wire, 4CH will be used automati-

ver if needed.

cally no matter which switch setting is

selected.

1 LPF (low-pass filter)/HPF (high-pass fil-

ter) select switch

4 FREQ (cut off frequency) control

Switch the settings based on the connected

Cut off frequency selectable from 40 Hz to

speaker.

500 Hz if the LPF/HPF select switch is set to

! When the Subwoofer is connected:

LPF or HPF.

Select LPF. This eliminates high range

! You can select cut off frequency only for

frequency and outputs low range fre-

CHANNEL B.

quency.

! When the full range speaker is con-

5 BASS BOOST (bass boost level control)

nected:

switch

Select HPF or OFF. HPF eliminates low

You can select a bass boost level from 0 dB

range frequency and output high range

to 12 dB.

4

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Black plate (5,1)

Section

Setting the unit

02

English

! Bass boost level setting applies only to

Relationship between amplifier gain

CHANNEL B (channel B) output.

and head unit output power

6 Power indicator

The power indicator lights up to indicate

power ON.

Setting gain properly

! Protective function included to prevent

malfunction of the unit and/or speakers

If amplifier gain is raised improperly, this will

due to excessive output, improper use or

simply increase distortion, with little increase

improper connection.

in power.

! When outputting high volume sound etc.,

Signal waveform when outputting at

this function cuts off the output for a few

high volume using amplifier gain

seconds as a normal function, but output

control

is restored when the volume of the head

unit is turned down.

! A cut in sound output may indicate impro-

per setting of the gain control. To ensure

continuous sound output with the head

unit at a high volume, set amplifier gain

control to a level appropriate for the preout

maximum output level of the head unit, so

that volume can remain unchanged and to

If the signal waveform is distorted due to high

control excess output.

output, even if the amplifier gain is raised, the

! Despite correct volume and gain settings,

output power will change only slightly.

the unit sound still cuts out periodically. In

such cases, please contact the nearest

authorized Pioneer Service Station.

Gain control of this unit

Preout level: 2 V

(Standard: 500 mV)

Preout level: 4 V

Above illustration shows NORMAL gain set-

ting.

5

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