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Rockford Fosgate Punch 400S

100W x 2 Car Amplifier

2 Reviews

Item # 575400S

This item is no longer available.

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Our take on the Rockford Fosgate Punch 400S

Rockford Fosgate's Punch series amplifiers are designed to meet exacting standards of efficiency and effectiveness. Plug the Punch 400S into your system and hear how it lives up to its name — two channels of 100 watts RMS power are waiting to supercharge your speakers or subs!

Rockford Fosgate's Punch series amplifiers are designed to meet exacting standards of efficiency and effectiveness. Plug the Punch 400S into your system and hear how it lives up to its name — two channels of 100 watts RMS power are waiting to supercharge your speakers or subs!

Built-in high- and low-pass crossovers let you tailor output to your speaker configuration. Remote Punch Bass (0-18 dB bass boost at 45 Hz) adds even more snarl to the growling low frequencies, from the convenience of the driver's seat. You'll appreciate the quality of the special-design pre-amp section and the MOSFET outputs when you drive this amp hard — you'll hear your music loud and clear, with minimum distortion and maximum musicality.

And if you need to save space in your vehicle, you can remove the endcaps for a wider range of installation options.


  • 100 watts RMS x 2 at 4 ohms
  • 200 watts RMS x 2 at 2 ohms
  • 400 watts RMS x 1 at 4 ohms in bridged mode
  • stereo or bridged mono output
  • Tri-way capable (Tri-Way crossover required)
  • 50-210 Hz high-pass/low-pass (12 dB/octave) crossovers
  • MOSFET power supply and output devices
  • MEHSA mounting technology increases the heat transfer from the MOSFET output devices to the heat sink, for higher power output, lower operating temperatures, and greater reliability
  • TOPAZ — noise-killing differential inputs that eliminate 80% of ground loop noise
  • Trans•ana circuitry keeps preamp voltages low and signal paths simple for outstanding audio quality
  • NOMAD — advanced protection circuitry for "intelligent" shutdown protection
  • wired remote included for fingertip control of Punch Bass (0-18 dB boost at 45 Hz)
  • speaker- and preamp-level inputs
  • dimensions: 12-13/16"W (8-13/16" without endcaps) x 2-1/2"H x 9-13/16"D
  • 2-year warranty

Its a great amp!I got it and it blew my 2p3 tens and it drives my 12s with power.

patrick Sr., orange texas 77630

What's in the Box:

  • 2-Channel amplifier
  • RF center badge
  • Remote Punch Bass control
  • 15' Remote Punch Bass cable
  • Remote Punch Bass mounting bracket
  • Two 3/8" self-tapping screws
  • Self-adhesive Remote Punch Bass control decal
  • Remote Punch Bass control knob
  • One 9" speaker-level input harness
  • Twelve 3/32" Set screws
  • Four 3/4" self-tapping screws
  • One 7/64" Allen wrench
  • One 3/32" Allen wrench
  • In-line fuse holder
  • ATC 40-amp fuse
  • 2 Black rubber boots (for use with in-line fuse holder)
  • Installation and Operation Manual
  • Punch Verification Certificate
  • "Team RF" sticker

Rockford Fosgate Punch 400S Reviews

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(2 Reviews)
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Product Research

Inputs and Outputs


Trans-ANA (TRANSconductance Active Nodal Amplifier): The Trans-ANA is a circuit that allows the audio signal to pass through the amplifier at low voltage. The signal is directly level-shifted to the fixed high voltage rails via a pair of drive transistors. Signal linearity is assured by an active node formed  by the drive transistors at ultrasonic frequencies. The result is crystal clear sound quality, even at high volume levels.

MEHSA (Maximum Efficiency Heat Sink Application): MEHSA is a Rockford Fosgate proprietary process that increases the heat transfer from the MOSFET devices to the heatsink. The multi-layer insulated metal MEHSA substrate operates with minimal thermal resistance, spreading heat both downward and outward to quickly dissipate heat from each device across the heatsink. This allows greater power output, enhanced thermal stability, and maximum reliability.

TOPAZ (Tracking Operation Pre-Amplifier Zone): TOPAZ is a circuit that simply eliminates noise. The TOPAZ circuit allows the amplifier ground to move with the source unit ground, creating a "noise elimination" zone just before the preamp section. If there is any noise in the ground coming down the RCA line to the amplifier, TOPAZ amazingly tracks it down and eliminates it. The result is a 30-40dB improvement of the isolation between input ground and chassis ground. 

DSM (Discrete Surface Mount): In the manufacturing process high speed robotics are used to place 0% tolerance resistors and large board traces providing greater reliability and efficiency.

NOMAD (NOn-Multiplying Advanced Decision): NOMAD is an intelligent protection circuit that uses an analog computer to make real time decisions regarding temperature, voltage, current and impedance. The unit is protected without limiting sound output unless needed.

INDIGO (INDexed Ideal Gain Operation): INDIGO is a circuit that maximizes the output power of the amplifier by making better use of the power supplied by the car. As the battery voltage drops, INDIGO tightens up so the amplifier delivers the rated power, resulting in more consistent power coming from the amp.

Internal Crossover: The internal crossover is a 12dB/octave Butterworth filter variable from 50Hz to 210Hz. The crossover may be set for high-pass, full range, or low-pass operation.

Remote Punch Bass: The Punch Bass feature helps correct for acoustical deficiencies in the listening environment by helping reproduce full range sound without adding excessive boost. The Punch Bass control has a narrow band adjustment centered at 45Hz, variable from 0dB to +18dB. Using the mounting bracket, the supplied Punch Bass wired remote can be mounted in any convenient location under your vehicle's dash. The wired remote is 2.317" wide, 1.523" tall and 2.035" deep. The included cable is 15' in length.

RF Center Badge: Upon arrival, the RF center badge is not adhered to the amplifier. For installation flexibility, the badge can be rotated 180 degrees. Once you've decided in which direction the badge looks best for your installation, the peel-and-stick backing on the badge can be used to attach it to the amplifier.


Left Side Of Amplifier:

  • Crossover Switch: allows you to select high-pass, full range, or low-pass crossover operation
  • Crossover Frequency: the crossover frequency control is variable from 50Hz to 210Hz
  • Left Gain: this variable gain control allows you to adjust the output level of the left channel
  • Right Gain: this variable gain control allows you to adjust the output level of the right channel

Inputs and Outputs

Left Side Of Amplifier:

  • Input: gold-plated RCA jacks
  • High Level Input: Molex plug input for included harness
  • Speaker Outputs: gold-plated set screw terminals that will accept up to 8 gauge speaker wire
  • Remote Punch Bass: RJ-14 jack for use with supplied Remote Punch Bass wired remote

Right Side Of Amplifier:

  • GND (ground): gold-plated set screw terminal that will accept up to 8 gauge wire
  • B+ (power): gold-plated set screw terminal that will accept up to 8 gauge wire
  • REM (remote turn-on): gold-plated 0.250" quick-slide for remote turn-on lead. Note: A female quick-slide is not supplied.


Dynamic Power Rating (measured at 14.4V):

  • Bridged Into A 4-Ohm Load: 400 watts x 1
  • Per Channel Into A 2-Ohm Load: 200 watts x 2
  • Per Channel Into A 4-Ohm Load: 100 watts x 2


  • Without Endcaps: Height=2.489", Depth=9.8125", Width=8.8125"
  • With Endcaps: Height=2.489", Depth=9.8125", Width=12.8125"

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