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Cool and Compact Amps

Sometimes size doesn't matter. Alpine packs Class-D amplifier technology into their PDX amplifiers for awesome power from a compact frame. These small-but-mighty amps free up valuable space and run so cool they can be stacked together for a sweet multi-amp setup.

stackable up to 3 high

Heavy-duty, clean power

The PDX-4.150 4-channel amplifier supplies 150 watts of full-range power to each channel, plenty of power for the most demanding component speaker systems or most subs. Beefy internal components and clever engineering keep the power output strong and the noise low for superb fidelity and control. Adjustable frequency filters tailor the amp's output to your specific system.

High-quality connections

your description here

Front-mounted controls make post-installation adjustments a snap. Gold-plated RCA inputs and power connections resist corrosion and signal degradation. Nifty speaker wire plugs ensure a tight connection and guarantee that your speakers work in unison.

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

Product Highlights:

  • 4-channel car amplifier
  • 150 watts RMS x 4 at 4 ohms (150 watts RMS x 4 at 2 ohms)
  • 300 watts RMS x 2 in bridged mode (4-ohm stable in bridged mode)
  • variable high- and low-pass filters (30-400 Hz, 12 dB/octave)
  • Class-D amplifier design
  • stackable installation design with front-panel controls
  • quick-connect speaker connectors
  • preamp-level inputs
  • MOSFET power and output stages
  • CEA-2006 compliant
  • fuse rating: 30A x 2
  • 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 10-3/16"W x 2-1/2"H x 8-7/8"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.

Alpine PDX-4.150 Reviews

Average Customer Review:

8 reviews
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great amp

Written By john, coon rapids ,mn on Sunday, April 10, 2011

great amp. very versitile i have it running a pair of 10" alpine type "e" subs in a atrends sub box that fits under the back seat of my silverado. The subs hit good and have no detectable distortion. Or i could use it to run other speakers in my truck instead

LOVE IT!!!!!!!

Written By bigredishott, Springfield, MA on Monday, May 11, 2009

I bought this amp to replace a Alpine MRV-F345, and to power a set of Infinity Kappa Perfects 6.1 and Infinity Ref. 9622i. It is amazing.
The clean power this amp delivers is unprecedented, I have never had an amp for my highs deliver so, nicely! You would think I had new speakers installed as well.
I must warn you, if you have any engine noise, get it fixed prior to installing this amp. I had a tiny bit of whining, (picked up at HU) since I replaced my plugs and wires. (used cheap stuff) It wasn't enough to bother me, with my old amp. With this amp, it became unbearable, I had to take care of the problem immediately with new wires and plugs. Since that, I will give this amp 5 stars all day long!

I would recommend this amp to anyone!

awesome !!!!!!!!!!

Written By hightower, marion al. on Monday, October 13, 2008

The best mids and highs amp ive ever owned ! Dont even think about it ! Just buy it ! No if, ands, or buts ! Very dinamic and sound so clean and so
real that your friends will all be talking about the way your stereo sounds !

ive owned jl audio slash series, fosgate, and mtx amps. These alpine amps will impress even the unimpressable ! Thats A PROMISE ! Do not compare these amps to the older v12 series. The older alpine amps werent dynamic at all but the pdx series will make very dynamic ! people were telling alpine what they want in an amp and alpine was deffinatelly listening ! i can have the volume turned all the way up and cant even tell my stereo is on untill the first instrument is played. Just buy this amp and dont think u are gonna get anything but the VERY BEST ! If mine was stolen id call crutchfield and order another one instantly.

Mixed Review

Written By ppod, Cleveland, OH on Saturday, April 26, 2008

I installed this amp to power two sets of component speakers but was left with mixed feelings.

The power and chanel separation is impressive. The amp is also surprisingly dymanic when playing jazz and blues. Unfortunatly, there is a significant amount of noise in this amp and as a result, I have returned it.

Overall, it provides alot of power for the price but the sound quality is not acceptable. I am told that the noise is result of the class D design. If that is case, I think anyone interested in sound quality would be better served by a less powerful AB style amp. Leave the class D's for subwoofers.

Great Quality

Written By Samyson, California on Friday, November 30, 2007

This amp brought out so much color from my speakers. The power that it puts out really lets the mids sing, and the highs dance around your ears. The small package that it comes it can not be beat. My birth sheet said 168w rms and my components love each and every watt. They make my speakers get loud, and I mean LOUD without any distortion. I have to turn it down to not make my ears bleed. I was hesitant about getting a type D amp for my components, but I sucked it up anyways and was not disappointed. It did tons better than my old A/B amp that I got on budget. Very happy with this amp. You can not get a better amp for the space it takes up and the power it produces. It does get warm, but sitting next to a PDX 1000.1 in small, closed area does bring the temperature up a bit. Quality is not sacrificed. Keep on rocking.


Written By MRMAP13, Charlotte,NC on Wednesday, May 16, 2007

Alpine PDX AMPS.... I have been purchasing car audio electronics from C/F for years. Recently i purchased a large amount of Alpine car audio, IVAD-310,PXA-H701,RUX-701, to get a true theater sound quality. While using Boston Z6 components in all doors and focal center channel, the next step was to was to supply the power. So after comparing, i decided on two pdx 1.1000 to power to jl12w7 and two pdx 4.150. These amps not only were superior in sound quality, they were above and beyond the power rating stated. A MUST BUY from C/F and ALPINE!!!

Alpine PDX-4.150

Written By falz, Madison, WI on Monday, January 08, 2007

Picked up one of these last week- I had a 14 or so year old Rockford Fosgate DSM Punch 200, and an 7ish year old two channel Eclipse amp. Replaced both of them with this four channel, and the sound quality seems stellar.

Although this amp certainly isn't cheap, it seems to deliver clean power to my seperates and bridged sub.

It's not 100% clear on how to bridge a channel in its manual. To do this use the POSITIVE of the odd numbered channel(1 or 3) with the NEGATIVE of the even numbered channel (2 or 4). So in my case, I used 3+ and 4- to bridge my sub.

alpine quality

Written By tony, houston tx on Friday, June 16, 2006

had this baby tested for me and its 176 true rms watts per channel. this amp is a champ.

Hands-on research

What's in the box?

Download owner's manual

  • 4-channel amplifier with two 30-amp blade fuses installed
  • 4 Speaker quick connect terminals
  • 4 Joint caps (for stacking multiple amps)
  • Four 1-1/2" Self-tapping screws
  • Four M4 x 36mm Machine screws
  • Eight M2.6 x 14mm Machine screws (with lock washers attached)
  • 2mm Allen wrench
  • 4mm Allen wrench
  • Owners Manual (English/French/Spanish)
  • Customer Care Registration/Survey
  • Warranty sheet
  • Specification verification certificate

Product Research



PDX Amplifier Design: Class-D amplifiers boast higher efficiency, produce much less heat, and draw less current than traditional Class-AB amps. The PDX series is Alpine's totally new super-efficient power density design of full range class-D amps. They combine MOSFET power supplies, MOSFET final outputs, and a thermal management processor, along with a 4-Layer Glass Epoxy PC Board to create a high-end sound quality without the bulky heat sinks required by most amps with this much power.

STAR Topology: Alpine's unique STAR (Signal Transit for Accurate Response) Circuit PCB design provides a single common ground for all amp sub-blocks, preventing ground interference and minimizing internal noise.

Terminal Layout: For wiring convenience all the inputs and outputs on the amp are on one side.

Verification Certificate: The amplifier comes with a certificate that lists the RMS power output of the individual amplifier. It also lists the model number, serial number, test date, and the test conditions (14.4 volts, 4 ohms).

Speaker Connecters: The PDX series amps use a new Speaker Quick Connect plug to attach the speaker wires to the amp. Bare speaker wire, up to 8 gauge, is held in place by a set screw, the Quick Connect plug then plugs into the amp. Like an RCA jack, the Quick Connect plug uses a center positive layout, so it fits two ways and both maintain correct polarity.

Stack Amps: Because the PDX series design generates so little heat, up to three amps can be stacked and bolted together. All three amps in the series, PDX-2.150, PDX-4.150, and PDX-1.1000 share the same footprint, so they can be stacked together.

Notes: When stacking multiple amplifiers, do not install vertically or at an incline. Any stack installation other than parallel to the vehicle floor, invalidates the warranty.

LED: The top mounted LED Power/Status indicator glows blue when operating normally and red when one of the protection circuits engages.

Protection Circuits: This amplifier includes protection circuits to prevent damage due to the following conditions:

  • ambient temperature too high
  • supply current too high
  • short to ground
  • over voltage


Controls (front of unit): Once set, the controls are covered by a door.

  • Crossover Mode switch: set to HP (high pass), OFF (full range) or LP (low-pass), separate controls for the front and rear channels
  • Crossover Frequency: rotary controls used to select the crossover frequency, separate controls for the front and rear channels, variable from 30 to 400Hz
  • Gain control: rotary controls used to set the amplifier's gain according the level of the incoming signal, separate controls for the front and rear channels, continuously variable from 0.2V to 4.0V
  • Input switch: set to 1+3/2+4 (input 1 and 3 summed to feed channel 3, inputs 2 and 4 summed to feed channel 4, this makes channels 3 and 4 non-fading), 3/4 (channels 3 and 4 fed by inputs 3 and 4, maintains fader when head unit has front and rear line outputs), or 1/2 (channels 3 and 4 fed by inputs 1 and 2, no Y-adapters needed when head unit has only one pair of line outputs)


Inputs and Outputs (rear of unit):

  • Power and Ground terminals: power and ground terminals are gold plated set screw terminals, will accept up to 4 gauge bare wire, Alpine recommends 6 gauge wire minimum
  • Remote Turn-on terminal: gold plated set screw terminal, will accept up to 10 gauge bare wire
  • Speaker terminals: each of the 4 speaker outputs uses Alpine's Speaker Quick Connect plug
  • Line Level Input: 4 female RCA jacks, left and right for the front and rear channels, gold plated

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.