Rockford Fosgate 4 Channel 400 Watt Class AD AmplifierT400X4ad — Big Jeff Audio Dealer Platform
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  • This Listing Includes: (1) T400X4ad 400 Watt 4-channel Amplifier
  • Total Power: 400 Watts
  • Frequency Response: 20Hz-20kHz +/-1dB
  • Number of Channels: 4

Rockford Fosgate 4 Channel 400 Watt Class AD AmplifierT400X4ad

The Power T400X4ad 400 Watt 4-channel ultra-compact, amplifier is built on Rockford Fosgate's proprietary Class-AD technology, featuring Constant Power to produce the same output at both 4-Ohm and 2-Ohm impedances. Flexible vehicle integration enabled through low-level and high-level inputs with auto turn-on. Top mounted controls allow easy access to built-in crossover and C.L.E.A.N. input/output clip detection circuits. The 3-stage thermal lock extrusion with dual fan forced induction keeps everything cool while real-time thermal/protection schemes safeguard the amplifier.

This Listing Includes:

(1) Amplifier


- Rockford Fosgate proprietary Class AD technology

- 4/2 Ohm muti-impedance Constant Power

- Differential inputs with high level auto turn-on feature

- 8 AWG power/ground connector w/ upgraded RCA connectors

- Remote-Out feature when using high level inputs - 2/4 channel input switch

- 4 Ohm bridged capable

- C.L.E.A.N. input/output clip detection and indicator LEDs

- Top mounted controls - Dual fan cooled - Real time thermal sensing

- Dual extruded heat sinks

- Discrete surface mount technology


Number of Channels: 4

Total Power: 400 Watts

Frequency Response: 20Hz-20kHz +/-1dB

Input Sensitivity: 150 mV to 12 V

Circuit Topology Class: Class AD

Efficiency (average): More than 75%

Power Wire Gauge: 8 AWG

Power Input Connector: Detachable Compression Terminal

Speaker Wire Gauge: 16 AWG

Cooling: Dual Fan Cooled

Operating Voltage: 9 - 16 VDC

Recommended Fuse(not included): 60 A

Average Current Draw (13.8V Music): 28 A

Max. Current Draw (13.8V Sinewave): 55 A

Suggested Alternator: 75 A

Rated Power:

100 Watts x 4 @ 4-Ohm

100 Watts x 4 @ 2-Ohm

200 Watts x 2 @ 4-Ohm Bridged

Dynamic Power:

128 Watts x 4 @ 4-Ohm

152 Watts x 4 @ 2-Ohm

290 Watts x 2 @ 4-Ohm Bridged



Front Terminals: Left (+) Right (-)

Rear Terminals: Left (+) Right (-)

Total Harmonic Distortion (THD+Noise):

4-Ohm: less than 1.0%

2-Ohm: less than 1.0%

Signal Input:

Front High/Low Level Input: 4-Pin harness

Rear High/Low Level Input: 4-Pin harness

Tone Controls:

Treble: 0 to +14 dB @ 12.5 kHz

Bass: 0 to +18 dB @ 45 Hz

Crossover Controls:

High-Pass: 50Hz - 250Hz @ 12dB/Octave Butterworth

Low-Pass: 50Hz - 250Hz @ 12dB/Octave Butterworth

All-Pass: Yes

Visual Indicators:

Power: Blue LED

Protect: Red LED

Input Clip: Red LED3

Output Clip: Blue/Violet/Red LED1,2,3

LED Color Legend:

1BLUE: Less Than 0.5% THD


3RED: 10%+ THD

Speaker Output Connector:

Front: 4-Pin Harness

Rear: 4-Pin Harness


1.6 x 4.3 x 8.3 (in.)

4.1 x 10.8 x 21.1 (cm)


3.4 Lbs. (1.54 Kg.)

Payment Information


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or confirmed address to pay us through PayPal

With Free Same Business Day Shipping we work to get you your order Fast. 


All orders over $500 will require a signature for delivery.

All pre-selected shipping rates and methods are for customers with a
valid residential or commercial address within the Contiguous 48 United
States (PO Boxes address may require additional charges).

P.O. Boxes, APO/FPO addresses, Alaska, Hawaii, Puerto Rico, Guam,
U.S. Virgin Islands, Northern Mariana Islands, American Samoa, Canada,
and other countries may require additional shipping fees. Please contact
a member of our team for detailed shipping charges.

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payment please confirm your address has been verified with PayPal. Once
payment is made shipping address can not be changed/altered. Payments
made using an unverified PayPal address will be refunded and order will
be canceled.

We will not accept request to change shipping address once payment
has been made. Please confirm your shipping address is up-to-date and

Typical handling time for orders is 1-business day. We do our best
to ship every package with-in 1 business day of receiving a cleared
payment. In some circumstances additional time may be need, in which
case we will contact buyer.

Shipped orders that are returned by the shipping company due to an
insufficient address or an undeliverable address will be refunded less a
20% restocking fee.

If package is refused or marked undeliverable and returned
back to us by the carrier, you will need to pay the shipping cost in
full to have the package sent back to you or we can refund the money
minus the cost of shipping


If you have not received your package, but the tracking information shows that it was delivered,
please do the following within 36 hours of expected, stated delivery:


Verify the shipping address on the order is the address where you are looking for the package

Look for a notice of attempted delivery

Look around the delivery location for the package, or see if a neighbor has accepted the delivery

Be sure to double check your mailbox and other usual spots for package delivery


If you think that your package has been stolen, we will require a police report since this is now theft.
Once we have a police report on file for the stolen package, we will reship your order.