Alpine MRP-F450

4-channel car amplifier
70 watts RMS x 4

  • Alpine MRP-F450


  • Alpine MRP-F450


  • Alpine MRP-F450


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Item #: 500MRPF450

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Our take on the Alpine MRP-F450

by Ken Nail

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.

Alpine Authorized Online Dealer

Outstanding audio performance — you expect it when the amp is an Alpine. Alpine's V-Power amplifiers supply the high level of performance you want without shaking loose too much of your hard-earned cash.

The versatile MRP-F450 4-channel amplifier can take on a variety of roles in your system. Drive your front and rear speakers in 4-channel mode, or switch to 2-channel mode to bridge the output and get a pair of subs thumping with 200 watts of power each. Want the best of both worlds? Use channels 1 and 2 to power full-range speakers, and bridge channels 3 and 4 to power a sub. Any way you use it, this amp will impress you with its strong sonic performance.

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Variable high-pass/low-pass filters let you adjust the frequency output for either full-range speakers or a sub. If you're driving a subwoofer and using the low-pass crossover, a subsonic filter eliminates inaudible, ultra-low bass notes for cleaner output.

The amp's rugged construction ensures reliable performance. A heavy machined-metal heatsink keeps the internal parts cool and distortion low. Gold-plated screw terminals resist corrosion that can degrade signal performance.


  • 4-channel car amplifier
  • 70 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • 200 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)
  • 2-, 3-, or 4-channel output
  • variable high-pass/low-pass filters (50-400 Hz, 12 dB/octave)
  • tuned Bass EQ (12 dB bass boost at 50 Hz for channels 3 & 4)
  • subsonic filter (15 Hz, 24 dB/octave for channels 3 & 4)
  • MOSFET power supply
  • CEA-2006 compliant
  • STAR Topology (minimizes internal noise and prevents ground interference)
  • speaker- and preamp-level inputs
  • preamp outputs
  • gold-plated screw terminals
  • fuse rating: 25A x 2
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 13-1/4"W x 2-3/8"H x 9-9/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Note: Sorry, Crutchfield cannot ship Alpine products to Guam or Puerto Rico.

Hands-on research from the Crutchfield Labs (what are the Labs?)

Features and Specs
RMS Power Output (Watts x Channels) 70 x 4
Peak Power Output (Watts x Channels) ---
Power at 2 Ohms (Watts x Channels) 100 x 4
Bridged Power (Watts x Channels) 200 x 2
Minimum Impedance Bridged 4
Minimum Impedance Unbridged ---
Best Frequency Response 10-50k Hz
THD at Rated RMS Power 1%
Signal to Noise Ratio 100 dB
Input Voltage 14.4v
Amplifier Class AB
Low-Pass Crossover Frequency 50-400 Hz
Low-Pass Slope (dB/octave) 12 dB
High-Pass Crossover Frequency 50-400 Hz
High-Pass Slope (dB/octave) 12 dB
Bass Boost 12db
Bass Boost Frequency 50 Hz
Fan Cooled No
Fuse Rating 25 x 2
Speaker Level Inputs Harness
Preamp Outputs 1 pair
Width (inches) 13-1/4
Height (inches) 2-3/8
Depth (inches) 9-9/16
Parts Warranty 1 Year
Labor Warranty 1 Year
Product Research
What's in the box?

Download owner's manual

  • 4-Channel amplifier
  • 8" Speaker-level input harness (with 8-pin Molex plug on one end and bare wire on the other end)
  • 2 Terminal covers
  • 4 Self-tapping hex-head screws (M4 x 20)
  • 4 Machine screws for securing terminal covers (M3)
  • Owner's Manual (English/French/Spanish)
  • Customer Care Registration card

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 open the box, verify contents, 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.

Inputs and Outputs


Power Supply: The MRP-F450 amplifier's power supply uses MOSFETs to convert DC battery voltage to the higher DC voltages needed for high power. It supplies positive and negative voltages around 0V, rather than around 6V as with conventional single-polarity power supplies. The result is higher power levels and a dynamic range wider by as much as 10dB.

Gain Controls: This amp has independent front and rear channel gain controls.

Crossovers: Both front and rear channels have independently selectable high-pass and low-pass variable 50-400 Hz crossovers with a slope of 12dB/octave.

Subsonic Filter: This amp utilizes a 15Hz subsonic filter to eliminate super low frequencies that can rob power and damage speakers. The subsonic filter operates only for the rear channels, and is engaged when the rear channel crossover is set to "low-pass" operation.

Bass EQ: The Bass EQ circuit provides a fixed boost of 12dB at 50 Hz for the rear channels only. The Bass EQ does not function when the amp's rear-channel crossover is set to "high-pass" operation.

Inputs: The amplifier offers both line-level and speaker-level inputs for 4 channels. The supplied speaker-level input harness allows you to connect this amplifier to a receiver without preamp outputs, either aftermarket or factory.

Line Outputs: This amplifier has a pair of non-fading stereo RCA line outputs. You can use these outputs to daisy-chain another amplifier without having to run additional signal cables from the receiver.

Terminal Cover: The amp comes with two plastic covers that protect and insulates the RCA, power, and speaker connections. Four supplied machine screws attach the cover to the amplifier.

Inputs and Outputs

Left Side Of Amplifier:

  • GND (ground): Gold-plated terminal strip, 0.35" wide
  • Battery: Gold-plated terminal strip, 0.35" wide
  • Remote: Gold-plated terminal strip, 0.35" wide
  • Speaker Outputs: Gold-plated terminal strips for 4 speakers, 0.35" wide

Right Side Of Amplifier:

  • Line Inputs: 2 pairs of gold-plated stereo RCA jacks
  • Line Outputs: 1 pair of gold-plated stereo RCA jacks
  • Speaker Level Input: Molex plug input for supplied 8-pin harness
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Alpine MRP-F450 Reviews

Average Customer Review:

13 people say:

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5 out of 5

Great Amp!

Written By CatSnak, Lakeside, CA on Thursday, April 24, 2008
Crutchfield Customer Review (What's this?)
Installed this behind my Pioneer head unit and use it to power 4 Infinity
Kappa 6x8's for some great sound. It fits very nicely under the rear seat
and was very easy to install.
1 out of 1 people found this helpful
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5 out of 5

Very happy with this amp

Written By James, MI on Sunday, October 07, 2007
Have had this installed for a few months now & it is definately a great amp. It has clean power in spades and the the fidelity is also very good (it's running Alpine S-series coaxials all the way around). Lots of adjustability with the onboard x-overs and bass boost, makes fine tuning my sound alot easier. It is also very quiet & seems very well built. Nicely done, Alpine!
2 out of 2 people found this helpful
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5 out of 5

Good Amp Real Clean

Written By JJ, Woo Ohio on Sunday, July 22, 2007
I got this amp powering my component and coax R series Alpines with the 205 DVD CD in my H3. The amp is clear sounding and packs a punch. The price is right and sounds great, you can't beat it.
1 out of 1 people found this helpful
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5 out of 5

Alpine MRP-F450

Written By rvd03, san bernardino, ca on Tuesday, July 17, 2007
i've had this amp for about 3 weeks and it is great. i have this hooked up to 2- 10inch alpine type S subs and geez, this is kickin some major butt with those subs along with my other components. highly recommend this it might be pricy for some but it is worth it.
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5 out of 5


Written By Fred, Daytone Beach, FL on Saturday, April 07, 2007
Crutchfield Customer Review (What's this?)
powering apline components up front and jbl power in the back and it sounds amazing. i will always amplify my speakers from now on instead of using just the head unit. If you dont have a lot of room as is the case in my truck and you dont want to sacrifice space with a big sub but still want to here bass then get an amp like this to get the most out of your components
4 out of 4 people found this helpful
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5 out of 5

Fantastic Product

Written By Mark, Fla on Friday, February 16, 2007
This is the deal of the century! Easily powers 4 Polk db series components with perfection. Runs cool, looks cool, and sounds great!
3 out of 5 people found this helpful
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5 out of 5

Great amp!

Written By Ken, Little Rock, AR on Sunday, January 28, 2007
Crutchfield Customer Review (What's this?)
I recently decided to upgrade my existing Alpine setup (10 yr old) by adding a set of rear speakers and another amp. I chose this amp, and I'm glad I did. It is powering a pair of JBL Power P552's in the dashboard and a pair of Infinity Reference 9613i's in the rear. From barely audible to painfully loud (the kind of loud that leaves your ears ringing for an hour or so afterword) the quality and precision of the sound is amazing. Highly recommended.
6 out of 6 people found this helpful
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5 out of 5

Great amp!

Written By Len, Phoenix, AZ on Sunday, December 10, 2006
Crutchfield Customer Review (What's this?)
I have installed, sold and owned audio systems for over 30 years and have experienced all types of combinations. I am using this amp to power two sets of Infinity 5x7 component speakers. This is a very satisfying combination, a very musically accurate amp with very efficient speakers. Tremendous results, especially considering dollars spent. I couldn't be more satisfied.
3 out of 4 people found this helpful
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5 out of 5

Alpine MRP-F450

Written By Mark, Daytona Beach, FL on Tuesday, October 03, 2006
Crutchfield Customer Review (What's this?)
This amp is great. I have built 3 systems over the years and I won't stray from Alpine. This amp is loaded with all the options of all the others but it is crystal clear. I am using this amp to power 2 sets of XR650-CSi's and it is crystal clear. Great Amp!
3 out of 4 people found this helpful
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5 out of 5

Alpine MRP-F450

Written By John, Bethel, VT on Monday, September 18, 2006
This amp is what you would expect from Alpine.
Nothing but the best!

The crossover and gain controls are helpful once you learn how to use them. The filters for the sub make it all the better.
3 out of 4 people found this helpful
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5 out of 5

Excellent amp.

Written By Richard, Corinth,MS. on Saturday, July 22, 2006
Crutchfield Customer Review (What's this?)
The MRP-F450 seems to have plenty of clean power. I wasn't looking to shatter any windows, but it probably could..I'm very satisfied with the product..Alpine seems to have kept quality as a high priority..
1 out of 3 people found this helpful
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5 out of 5

Alpine MRP-F450

Written By Lee, UT on Monday, April 24, 2006
Awesome amp!!! Hits both highs and lows very cleanly. Im running 4 MB Quart 6X9s and I think the wattage rating at 70 watts RMS is a little low. This amp makes those puppies MOVE!! For about $300 this amp very much worth it.
15 out of 15 people found this helpful
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5 out of 5

Simple, Powerful, Clean and Reliable

Written By ModernGrowl, east coast on Tuesday, March 14, 2006
You actually see where your setting your hi-pass/low-pass filters!!!
Anyways, the sound is very clean, much more power then I will ever need for my internal speakers. I have the gain set to 'norm' or 12 o'clock, and that's all I need. I'm running two Type R components up front, and two Alpine 6x9's in the rear. The amp behaves like it should. Low end punch is nice and firm, and the highs are clean without sounding too harsh.

Thumbs up Alpine. Good amp!
51 out of 55 people found this helpful
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