Operation; Adjusting Gain; Adjusting Crossover Frequency; 2/4 Channel Switch - Rockford Fosgate M400-4D Installation And Operation Manual

O
PERATION

ADJUSTING GAIN

1.Turn amplifier gains to minimum (counter-clockwise).
2.Turn the source unit volume up to 7/8 maximum (or when distortion is just inaudible).
3. Slowly increase amplifier gain control until adequate volume is achieved.
NOTE: Best signal to noise and dynamic range are realized with gain set to minimum. For a more in
depth setting procedure, contact Rockford Technical Support.
CAUTION: Avoid setting amplifier gain high as noise and distortion will greatly increase.

ADJUSTING CROSSOVER FREQUENCY

Do the following individually for each channel.
Placing the crossover switch in the HP position sets the amplifier to the High Pass mode,
enabling frequencies above the cut-off point to pass, adjustable between 50-250Hz.
Placing the crossover switch in the AP position sets the amplifier to the All Pass mode,
preventing any crossover adjustment, allowing all frequencies to pass.
Placing the crossover switch in the LP position sets the amplifier to the Low Pass mode,
enabling frequencies below the cut-off point to pass, adjustable between 50-250Hz.
Turn the crossover adjustment knob all the way down.With the system playing, turn the
crossover adjustment knob up slowly until the desired crossover point is achieved.

2/4 CHANNEL SWITCH

Setting this switch to the 2CH. position, switches the inputs to a 2-channel mode, allowing
connection to only the front inputs with a 4-channel output.
Output controls function the same as if the amplifier was in 4-channel mode.
All "ACTIVE" inputs must have RCA jacks connected.
Switch in 2CH. position,"ACTIVE" - Front channel inputs only.
Switch in 4CH. position,"ACTIVE" - All Front and Rear channel inputs.
NOTE: When connecting to the 4-Channel inputs, be sure to route both front and rear
RCA cables tightly together.

PUNCH EQ

This works along with the crossover switch on the
amplifier.When set to Low-Pass (LP) operation, this
is a variable Bass Boost. Set this to your personal
preference while listening to the system.
CAUTION: Overexcursion and
subsequent damage may
occur at high levels of
boost.
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