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Overview: The Rockford Fosgate Power T400X4ad is an ultra-compact
four-channel amplifier. Even though the amplifier is only 8-5/8" x 4-1/4", it
puts out a full 100 watts per channel at 4 ohms or 2 ohms. In bridged mono, the output
is 400 watts at 4 ohms.
Class AD: The amplifier features Rockford Fosgate's proprietary Class
AD technology, which allows the amp to produce more power with less current
draw. It takes the highly efficient bd amplifier design to a full-range
application. Class AD uses Dynamic Frequency Switching to increase the switching
frequency during lower output levels for better signal resolution. In addition,
Post Choke Feedback Filtering removes unwanted distortion by comparing the input
signal to the output signal at the speaker connector.
Constant Power: Rockford Fosgate uses a patented circuit design to
gain up to 25% more output power. Constant Power actively increases the voltage
and current in direct relationship to the rise and fall of music signals to
provide additional power.
Fan Cooled: The T400X4ad features dual fans to keep the amp running
cool. Dual Fan Forced Induction pulls in fresh air, which pulls heat off of the MOSFETs, and directs airflow into the exhaust channel and out of the amplifier.
Since the top and bottom heat sinks are decoupled, the top remains cool to the
touch. When installing, you should leave at least 2-3" of clearance around the
ends of the amplifier to optimize air flow to the fan intake and exhaust vents.
C.L.E.A.N. Technology: Using Rockford's C.L.E.A.N. (Calibrated Level
Eliminates Audible Noise) technology, you can easily and precisely set up the
amplifier levels to eliminate distortion from damaging your speakers. Simple LED
indicators are used, instead of test equipment, to identify signal clipping at
both the input and output, and to match the audio source to the amplifier.
Top Mounted Controls: The T400X4ad features easy-to-reach controls on
the top panel of the amplifier. There are two sets of controls: one for the
front channels and another for the rear channels. The controls include:
- 2/4 Channel Switch: This switch determines which inputs
are active. In the 2CH position, only the front inputs are active, allowing
you to feed the signal to all four channels with only a two-channel input.
In the 4CH position, both the front and rear inputs are active.
- Input Level: This rotary control lets you match the output of the
audio source to the amplifier. A small screwdriver (not included) is
required to set the levels.
- Punch EQ: The Gyrator-based Punch EQ eliminates frequency shift
with boost. It works in conjunction with the crossover switch on the
amplifier. When set to Low-Pass operation, it functions as a 0 to +18dB variable Bass
Boost at 45Hz. When set to High-Pass, it is a 0 to +14dB variable Mid-Bass and Treble Boost
When set to All-Pass, the Punch EQ boosts both the bass and treble
frequencies. A small screwdriver (not included) is required to set the
amount of boost desired.
- Crossover Switch: This 3-way switch lets you select Low-Pass
(LP), High-Pass (HP), or All-Pass (AP) on the Butterworth crossover.
- Frequency: The crossover frequency is constantly variable between
50Hz and 250Hz with a slope of 12dB/octave. A small screwdriver (not included) is required to set the
crossover cut-off frequency.
LED Indicators: The amplifier has three LED indicators on its top
- Input Clip Indicator: The input clip indicator works in
conjunction with the audio source's volume knob. It will illuminate red when
the audio source reaches its clipping point.
- Output Clip Indicator: The output clip indicator works in
conjunction with the amplifier's input level knob. It will illuminate red
when the output level has reached the clipping point. When setting the level
using test tones, you should adjust the output level until the LED glows
blue. If setting the output level using music, the LED should glow blue with
only an occasional red indication.
- Power/Protect: The Power LED illuminates blue when the unit is
turned on. If the LED turns yellow, a short circuit or too low of an
impedance has been detected at the speaker connections. If the LED turns
red, the amp has overheated and has shut down.
Left Side of Amplifier:
- Inputs: There are 4-pin Molex connectors for the front
and rear channels that work with the supplied RCA
Input Harnesses. The front harness has gray and white wires, while the rear
harness has purple and green wires. The amp will accept signals from either high-level (speaker)
or low-level (RCA) sources. If connected to a high-level input signal, the
amp's auto turn-on feature is active.
Note: For high-level input, you can either splice RCA plugs onto the
source unit's speaker wires, or cut the RCAs off of the supplied input harnesses and
splice on speaker wires from the source unit using the standard wire color
code (front left=white, front right=gray, rear left=green, rear right=purple).
Right Side of Amplifier:
- Power/Remote Terminals: The amplifier's Power, Ground, and Remote
terminals are located in a separate plug-in quick connector. The connector
has compression terminals that will accept up to 8-gauge wire. When
utilizing high-level signals for the auto turn-on feature is active, and the
Remote terminal can be used as an output to turn on/off up to two additional
amplifiers or other accessories. A small
screwdriver (not included) is required to tighten/loosen the compression
terminals. Once the wires are installed in the quick connector, the
connector can be plugged into the amplifier.
- Speakers: Two 4-pin Molex connectors work with the supplied
Speaker Output harnesses. The speaker wires can be spliced to the harness'
four 16-gauge wires and plugged into the amplifier.
Note: For 2-channel bridged mono operation, the
front left + and right - wires and rear left + and right - wires should be used to connect to the speakers (4Ω
Warranty Terms: Rockford Fosgate Power-series amplifiers
carry a two year warranty, when purchased from an Authorized Rockford Fosgate
Extended Warranty Offer: Rockford Fosgate offers a one-year
extended warranty (for a total of 3 years) when the amplifier is installed using
a matching Rockford Fosgate installation kit, such as the