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Don't let your sound system dance around the ring; fire up a 4-channel Punch series amplifier from Rockford Fosgate and enjoy a knockout performance every time! These amps will sting your speakers with plenty of clean power, while serving up the sound-shaping controls and high-quality components you need to create a heavyweight audio system.

Slam your speakers with a one-two combination of power and control with the Punch P4004 amplifier! With its innovative circuit design, MOSFET output stages, and proprietary technology, the P4004 will bring out extraordinary detail in your music, with ultra-clean power you just can't get from a lesser amp. You get 50 watts RMS by four channels to power two sets of full-range or component speakers — or you can bridge the P4004 for 200 watts RMS x 2 for a pair of subs.

The audio fanatics at Rockford Fosgate know that it takes more than just muscle to create a prize-winning car audio system. That's why the P4004 is equipped with variable high- and low-pass crossovers — which minimize distortion by sending your speakers only the frequencies that they can handle — and a Punch bass boost (0-18 dB at 45 Hz) with a wired remote for hands-on control. You choose the right settings for your car, your speakers, and your ears.

Product Highlights:

  • 50 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • 200 watts RMS x 2 at 4 ohms (4-ohm stable in bridged mode)
  • variable high-pass/low-pass crossover (40-400 Hz, 12 dB/octave)
  • variable Punch Bass boost (0-18 dB at 45 Hz) with remote
  • CEA-2006 compliant
  • Tri-way capable (Tri-Way crossover required)
  • 8-gauge wiring kit and 60-amp fuse recommended — wiring and hardware not included with amplifier
  • MOSFET power supplies and output stages
  • MEHSA transfers heat efficiently from the MOSFET devices to the heat sink for high performance
  • TOPAZ eliminates ground loop noise
  • trans-ANA circuitry keeps preamp signal clean
  • NOMAD "intelligent" protection circuitry
  • preamp outputs
  • 16-7/16"W x 2-3/4"H x 11-1/4"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Rockford Fosgate P4004 Reviews

Average Customer Review:

13 Reviews

Good buy

Written by: Manish from Nashville, TN on May 16, 2006

I have had this unit for about 3 months now and it has done well to earn my 5 star rating.I have been using fosgate amps for almost 4 years now and feel that this is probably the best 4 channel amp available for the price and power..Note: Fosgate amps are always underrated.They will give u you more RMS power which is quite obvious in the details that come with the product when purchased.I am using this amp for 2 6 by 9 's and a 12 inch sub.Definitely worth every penny spent on this product.



Rockford Fosgate P4004

Written by: Tom Scalzo from Rochester,NY on May 3, 2006

This amp is everything they say and more. It is conservatively rated at 60W per channel, my amp measured in at 105W per channel. What a pleasant surprize! I am running MTX 6.5" components in the doors and MTX 6X9's in the rear. This amp easily powers them to a performance level second to none. I am very pleased with my purchase and want to thank the Crutchfield advisers for their assistance.



Great Amp

Written by: Steve from Knoxville, TN on April 7, 2006

Crutchfield Customer Review (What's this?)

Perfect for four speakers. Great adjustments and great sound. No other amp needed.



Rockford Fosgate Punch

Written by: Tony from Auburn, Alabama on March 17, 2006

Crutchfield Customer Review (What's this?)

As with all the other Rockford Fosgate products I have seen, this amplifier is definitely high quality. I have never owned a Rockford Fosgate amplifier before, but now that I do, I am very satisfied with my purchase. My first thought of this amplifier was that it was rather expensive, however, upon closer inspection, I actually got a whole lot more than I expected. This amplifier, P4004, is rated at 50 watts per channel, four channels, into 4 ohms. When I got my amplifier, in the box was a Performance Verification Certificate. Each amplifier is tested at the factory to see how well it performs. My amplifier was tested with an output of 101 watts per channel into 4 ohms. That is more than double what this amplifier was initially rated. Now, the price tag seems to be more than fair. I have it hooked to two Pioneer 6x9s on my rear deck, and bridged to a Sony XPlod 12" Subwoofer. I couldn't be happier with the quality of my music. I finally get that extra sound that my Pioneer head unit failed to give me. (And then some...) I will probably buy another amp just like this one some time in the future, and amplify my front speakers, and drive another 12" subwoofer in the same manner to provide optimum imaging. The amplifier is visually appealing with the chrome covers as well. If you can afford the price tag, go for it. You will not be disappointed. If you know anything about the basics of electronics, you should have no problem installing this yourself. I would recommend you do a little research on speakers and amplifiers, and learn how they work, and what their ratings such as THD and RMS Power mean. It really helps you make an informed decision. Trust me.



Defective Unit... I'm not sure but its returned!!!

Written by: ModernGrowl from East Coast on March 13, 2006

Crutchfield Customer Review (What's this?)

I'm not sure if my unit was defective or not, but there was hardly any low end output. I was using it for interior speakers, and the amp seemed to cutt off all frequencies below 100hz, even when the filter was OFF!!! No Hi-pass, No Low-pass on, rather it was set to let all frequencies through. No Low End Bass at all... messed up crossover filters? Was mine defective? I'm not sure.
Also, the treble content of everything I listened to was ear bleedingly high. Too much treble! Some say this is clarity. I don't. I returned and got an Alpine 4 channel 70watt rms x 4. Everything was back to normal. Head units bass functions and hi-pass worked as it should.

Sorry Rockford, but I'm not a happy customer.



Hooray for Fosgate P4004...!!

Written by: Alby from Fairfax, Virginia on February 11, 2006

Crutchfield Customer Review (What's this?)

Yes, all i can say is that this amp is just sheer all around quality.With a multitude of wiring options there's no better amp.If you want to hook up 4 mid size speakers or a couple of subs it just doesn't get any better.As long as you don't cheap out on the amp wiring (power & audio cables) you'll enjoy this beauty for a long time.It's certainly no wonder why crutchfield has kept this item continued in 5 straight catalogs.It's just a remarkable thing.



Best amp for the Price

Written by: brentrynn from Los Angeles, CA on January 9, 2006

Crutchfield Customer Review (What's this?)

This amp is worth every penny. It is very powerfull. Mine was rated at 100 rms x 4. Which is double the rated power. It has so much power you will not be disapointed at all. Everything sounds a lot better.

If your in the market for a 50x4 rms amp that can do everything then this is the one for you. This one will be higher anyways since it is way underated but you amp will be perfect for what you need. If need more power buy a Rockford with a higher rating.



Leet Amp

Written by: Bill from Anoka, MN on November 17, 2005

I am using this amp to power my two 10" infinity reference subs, its a very versitile amp, wheather you wanto to power an combination of two, three or four drivers. Dont believe the RMS rating Fosgate claims, its about 25% higher. Remember to bolt your equipment down to protect from thieves, and some insurance companies only protect stereo equipment thats fastened down. A+ Amp




Written by: Derek from Oklahoma City, OK on August 6, 2005

Crutchfield Customer Review (What's this?)

This amp is absolutely awesome. It is rated for 50 x 4, but the spec sheet that came with it states that it is putting out 84 x 4. I used this amp to power my fosgate 5 1/4 components and a single fosgate 8" sub and the system sounds outstanding. I would recommend this amp to anyone needing a multi-channel amp. I've always been impressed with fosgate's high quality and this amp is no exception.



Hard working little amp.

Written by: Libbydude from Hayden, Idaho on July 31, 2005

I bought this amp a few weeks ago to replace another 4 channel I had. This amp is all you'll ever need if you are looking for loud, undistorted music with some bottom end. I have this amp running my front and rear speakers at 2ohm stereo and a sub bridged off the rear channels. Just be sure and either have this amp professionally installed or if you insist on doing it yourself use the correct guage power and ground wires. You will save yourself a great deal of disappointment. The only reason this amp didn't get 5 stars from me is the design. It seems to be built upside down to me with the cast aluminum portion of the chassis being the bottom. Just mount the amp on risers to keep it unobstructed and cool(er). This amp has made me a loyal fan of RF products.



Outstading Amp. Soud quality is highest priority with Rockford Fosgate

Written by: Michael from Norman Oklahoma on July 5, 2005

This is an outstanding amp. The sound quality is absolutely incredible. Rockford really cares about things like noise shielding and low THD and high signal to noise ratio. I actually got to see inside one. The parts look beautiful and the designers sign the circuit boards with their initials with the CAD program, a true sign of the quality and care that goes into these amps. It will run a sub easilly and it can run speakers far louder than you would ever actually want to run them. Very configurable and easy to use. I love this amp.



Worth every penny

Written by: tony from norfolk Va. on March 25, 2005

I have this amp running a set of JL Audio 1/2 in. tweeters, a set of JL Audio coaxial 5 1/4's up front, and a set of JL Audio coaxial 4's in the rear and I must say it sounds pretty darn good. I highly recommend this amp to any one.



great value for the cost

Written by: islandromeo81 from honolulu Hi on March 14, 2005

By far one of the most flexible amp i have ever owned you could literaly run your whole system off this one amp. aside from running your mids and highs you could run both left and right channels in 2ohm and use the back channels to power a sub. it gives great response to all freq and the lighted logo is a plus if you are a avid audio enthusist i highly recomend this amp you will not be dissapointed on how many possiblitys there are with it.... happy listening every one



Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier with 2 removable chrome covers
  • 4 Allen-head screws (installed)
  • 3mm Allen wrench
  • 4 Self-tapping screws (M4 x 20mm)
  • Remote Punch Bass controller
  • Remote controller mounting bracket
  • 3 Self-tapping screws (2.5mm diameter x 10mm)
  • 16.25' Flat remote cable (with RJ-45 plugs on both ends)
  • Installation & Operation manual (English/French/Spanish/German/Italian)
  • Punch Amplifier Performance Verification Certificate

Product Research

Inputs and Outputs Notes


Removable Chrome Covers: The Rockford Fosgate Punch P4004 amplifier features dual removable chrome covers. One of the covers conceals all speaker, signal, remote, power and ground connections, as well as the gain and crossover frequency controls for a cleaner installation.

Cast Aluminum Heatsink: The cast aluminum heatsink dissipates heat generated by the amplifier's circuitry. The inherent advantage of casting provides a 30% improvement of cooling over conventional extrusion heatsink designs.

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. 

Trans-ANA (TRANSconductance Active Nodal Amplifier): 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.

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.

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.

TO-247 MOSFET: The Punch P4004 utilizes ultra high performance MOSFET output devices, giving the amplifier more power handling capability as well as lower thermal impedance for more reliable operation, even under the harshest load conditions.

2/4-Channel Switch: The P4004 can be switched from a 4-channel mode to a 2-channel mode by pressing in the 2/4-channel switch. When operating in the 2-channel mode, the amplifier produces 4-channels of output with connections to only the front channel inputs.

Internal Crossovers: The amplifier's internal front and rear crossovers are 12dB/octave Butterworth filters, independently selectable for high-pass, all-pass (full range) or low-pass operation variable from 40Hz to 400Hz.

Remote Punch Bass: The Punch Bass 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. The module's case can be configured with the bracket above or below the module, or, without the case, mounted flush in your vehicle's dash (requires a 2" x 7/8" cutout with a maximum thickness of 3/8"). The wired remote is 2.281" wide, 1.214" tall and 1.509" deep (2.471" including the knob and cable connection). The included cable is 16.25' in length.

RCA Pass-Thru Jacks: The pass-thru jacks provide 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 amplifier location. The pass-thru jacks output a full-range signal.

Power Indicator and Protection LEDs: The RF logo, located on the top left of the amplifier, illuminates when the unit is turned on. The "Swirl" portion of the logo illuminates with the output signal level. A yellow "Protect" LED, located next to the RF logo, illuminates if a short circuit or too low of an impedance is detected at the speaker connections. Another yellow LED, labeled "Thermal", illuminates if the amplifier overheats. The amplifier will automatically shut down if either of the two LEDs indicate amplifier trouble.

Inputs and Outputs Notes

Power Connections: The power and ground terminals are nickel-plated captive c-clamp wire connectors and will accommodate up to 4-gauge wire. The remote turn-on terminal will accept wire sizes of 12- to 24-gauge. A Phillips-head or slotted screwdriver (not supplied) is required to tighten/loosen the terminals.

Speaker Connections: The 4-channel nickel-plated clamp wire connectors will accept wire sizes of 8- to 18-gauge. A Phillips-head or slotted screwdriver (not supplied) is required to tighten/loosen the terminals.

Remote Punch Bass Connection: An RJ-45 jack is provided for connecting the supplied Remote Punch Bass cable.


CEA-2006 Compliance: The specifications given by Rockford Fosgate for the Punch P4004 amplifier comply with the new CEA-2006 Amplifier Power Standard from the CEA (Consumer Electronics Association). All manufacturers who comply with the standard can display the CEA-2006 logo on their product.

Performance Verification Certificate: Each amplifier comes with a Performance Verification Certificate which lists the results of a 10-point performance inspection as well as measure the actual power output. The actual power output of the amplifier reviewed by Crutchfield was significantly higher than the rated power output.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.