Overview: The Rockford Fosgate Prime R400-4D is a 4-channel
full-range Class D amplifier. It is optimized to power a full-range front/rear
speaker system. You can also bridge the front and/or rear channels to run a
subwoofer or two. The Class D design is very efficient with a cast aluminum
heatsink to keep it in a small footprint.
CEA 2006 Compliant: The R400-4D's power ratings are measured
according to the strict standards dictated by the Consumer Electronics Association
(CEA). These standards allow you to accurately compare the rated power output of
all CEA 2006-compliant amplifiers, even different brands. Manufacturers who adhere
to the standards can display the CEA 2006 logo on their products and packaging. The
RMS power output is as follows (measured with a 14.4 volt input, <1% THD+N, 20 Hz-20 kHz):
- 4-Ohm: 75 watts x 4
- 2-Ohm: 100 watts x 4
- Bridged (4-Ohm): 200 watts x 2
LED Indicator: The amplifier is equipped with a top-mounted
LED indicator which illuminates blue when the
unit is turned on. The LED illuminates red when a
protection circuit engages (short circuit or too low an
impedance is detected at the speaker connections). The
amplifier automatically turns off if this occurs.
Mounting: The amplifier can be mounted vertically, horizontally,
or inverted using the supplied mounting screws; horizontal mounting (right side up)
will provide the best cooling.
Independent Controls: The R400-4D has independent,
top-mounted controls for the front and rear channels. The controls include:
- Gain Control: The amplifier has rotary gain controls (0
to 11) for front and
- Crossovers: The amplifier features independent Butterworth crossovers for
the front and rear channels. Each crossover can be set for low-pass, high pass,
or all-pass (full range). The crossover frequency is continuously variable
from 50-250 Hz with a slope of 12 dB per octave.
Punch EQ: The rear channel has an
independent Punch EQ (bass boost) control that works with the crossover switch.
When the rear channel crossover is set to low-pass, the Punch EQ can add a bass
boost, centered at 45 Hz, from 0 dB to +18 dB.
2/4 CH Switch: When the 2/4 CH switch is set to the 2 CH
position, the inputs are switched to a 2-channel mode. The signal on the front
input feeds all four output channels, however, you lose front to rear fading
capability. In the 4 CH position, the amp uses both front and rear inputs and
fading capability is restored.
Power Terminals: The power and ground terminals are nickel-plated
set-screw terminals, and will accommodate up to 4-gauge wire. The set screws can
be tightened/loosened with the supplied 3mm hex key.
Fuses: The amplifier does not have on-board fuses. A 40A
fuse should be placed on the power wire within 18" of the battery.
Remote Turn-On Terminal: The remote turn-on terminal is a
nickel-plated set-screw terminal that will accommodate up to 8-gauge wire. The
set screws can be tightened/loosened with the supplied 3mm hex key.
Speaker Terminals: The speaker terminals are nickel-plated
terminals that will accommodate up to 8-gauge wire. The set screws can be
tightened/loosened with the supplied 3mm hex key.
RCA Input Jacks: There are two pairs of RCA input jacks for
front and rear channels. They are nickel-plated to resist signal degradation caused
RCA Pass-Thru Jacks: The nickel-plated RCA pass-thru jack
provides a convenient source for daisy-chaining an additional amplifier without
running an extra set of RCA cables from the front of the vehicle to the