Skip Navigation

Alpine PDX-V9

5-channel car amplifier — 100 watts RMS x 4 + 500 watts RMS x 1

26 Reviews | 14 questions - 33 answers

Watch a product review

Our take on the Alpine PDX-V9

The Alpine PDX-V9 5-channel amp delivers a whopping 100 watts RMS each to four speakers at the same time it blasts 500 watts RMS to your sub setup. This amazingly compact amp uses beefy internal components and clever engineering to keep the power output strong and the noise low for superb fidelity and control. The adjustable crossovers feature an extended range of crossover points, allowing you to use this amp with component tweeters, midrange speakers, or midbass drivers.

Alpine Authorized Online Dealer

5-channel powerhouse

The Alpine PDX-V9 5-channel amp delivers a whopping 100 watts RMS each to four speakers at the same time it blasts 500 watts RMS to your sub setup. This amazingly compact amp uses beefy internal components and clever engineering to keep the power output strong and the noise low for superb fidelity and control. The adjustable crossovers feature an extended range of crossover points, allowing you to use this amp with component tweeters, midrange speakers, or midbass drivers.

They make a cool stack of amps

Alpine packs Class-D amplifier technology into this PDX amplifier for awesome power from a 2" tall frame. This small-but-mighty amp runs so cool that you can stack it together with other PDX amps into a single unit — the multiple heatsinks actually couple together to cool the entire stack. Each PDX Series amp offers the same 8" by 10" footprint, so they'll fit in hatchbacks, trunks, truck cabs, and any vehicles with limited space.

PDX-V9 connection panel

Front-mounted controls and pop-out connectors

Front-mounted controls make post-installation adjustments a snap, even when multiple amps are stacked together. Nifty removable speaker and power wire plugs make it easy to install or remove an amp, ensuring a tight connection while guaranteeing that your speakers work in unison. Gold-plated RCA inputs, outputs, and power connections resist corrosion and signal degradation.

PDX-V9 control panel

Worked perfectly boosting sound in all 4 speaker locations and my JL sub. Recommended by the helpful chat agent. They know what they are talking about!

Scott B, Houston tx

Featured Video:

What's in the Box:

  • 5-Channel Class-D amplifier (with two 40A ATO fuses inserted in chassis)
  • Battery connector plug
  • 5 Speaker connector plugs
  • Four M4 x 36mm Hex/Phillips-head self-tapping screws
  • 2mm Allen wrench
  • 4mm Allen wrench
  • Owner's Manual (Eng/Fre/Spa)
  • Verification Certificate
  • Limited Warranty Card
  • Online Registration Card

Product Highlights:

  • 5-channel car amplifier
  • 100 watts RMS x 4 + 500 watts RMS x 1 at 2 or 4 ohms
  • 200 watts x 2 bridged at 4 ohms + 500 watts x 1
  • CEA-2006 compliant
  • stackable installation design with front-panel controls
  • variable high-pass filter on front channels (30-6000 Hz, 12 dB/oct)
  • variable high-pass filter on rear channels (30-600 Hz, 12 dB/octave)
  • variable low-pass filter on subwoofer channel (50-600 Hz, 24 dB/oct)
  • variable subsonic filter on subwoofer channel (0-30 Hz, 24 dB/oct)
  • quick-connect speaker connectors
  • Class-D amplifier design
  • MOSFET power and output stages
  • fuse rating: 40A x 2
  • 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 10-1/8"W x 2-1/16"H x 8-9/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Alpine PDX-V9 Reviews

Average Customer Review(s):

(26 Reviews)
rewards card

Submit a review and enter to win a $350 rewards card

Review this product

Thanks for submitting your review

Most reviews are processed and published within 5 business days. You will receive a confirmation email once your review has been published.

Your Review

Use the stars below to rate the overall product on a scale of 1-5
Upload your photos

Not visible. Email associated with order.
(e.g., Charlottesville, VA)

Additional Fields (optional)


By submitting this review, you agree to our terms and review guidelines.

Filter by rating

Customer photos

<< >>

Hands-on research

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 super-efficient power density design of full-range and monoblock Class-D amps. They combine MOSFET power supplies, MOSFET final outputs, and a thermal management processor, along with a 6-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.

Power Management Processor: The Alpine PDX amplifier incorporates Alpine's new Power Management circuit. The Power Management Processor controls all aspects of amplifier performance, monitoring voltage, temperature and output to ensure uninterrupted power output for non-stop listening.

Uninterrupted Protection Circuits: If the amplifier gets too hot, the Thermal Protection circuit kicks in and gradually decreases output power until it cools down. Once cool, the power output automatically increases back to the previous level. If the circuit detects a Low Battery condition, it will gradually decrease power output if battery voltage becomes too low. Once the battery voltage increases, power will be restored. This interruption-free design allows for non-stop enjoyment with no hiccups or drop-outs, just clean, clear output.

Channel Design: The Alpine PDX-V9 can be configured as a 5-channel, 4-channel, or 3-channel amplifier. The amplifier is stable down to 2-ohms in stereo, and 4-ohms when bridged.

Low Impedance Stability: This amp is stable at low impedances and is capable of its rated power (100 Watts x 4 + 500 Watts x 1) from 2 to 4 ohms. This allows excellent flexibility with multiple speaker and subwoofer loads and is adjusted automatically.

CEA 2006 Compliant: The PDX-V9's power ratings are measured according to the strict standards dictated by the Consumer Electronics Association (CEA). These standards allow you to accurately compare the rated power output of all CEA 2006-compliant amplifiers, even if they come from different brands. Manufacturers who adhere to the standards can display the CEA 2006 logo on their products and packaging.

  • 4 Ohms: 100 watts RMS x 4 and 500 watts x 1 @ 14.4 Volts with <1% THD+N
  • 2 Ohms: 100 watts RMS x 4 and 500 watts x 1 @ 14.4 Volts with <1% THD+N
  • Bridged (4-ohm): 200 watts RMS x 2 @ 14.4 Volts with <1% THD+N

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).

Ultra-Wide Frequency Response: The Alpine PDX-V9 offers a super-wide, frequency range (5Hz-50kHz, +0/-1dB) for unparallel sound quality and detail.

Ultra-Low Output Impedance: With ultra-low output impedance, the PDX-V9 offers extremely controlled, tight bass for unprecedented sound quality. The amplifier's Damping Factor is rated at >500 for channels 1-4 and >1000 for channel 5.

High Signal-to-Noise: This amplifier is capable of S/N ratios up to 92dB S/N at 1W and 112dB S/N at rated power for extremely clean, uncolored sound. The PDX amp delivers crystal clear music every time, without unwanted background noise or static.

Power Supply: The PDX amplifier's power supply delivers tremendous headroom with low distortion and noise. The PDX amplifier has an extremely high total system efficiency of ~80% (power supply is rated at >90%, output stage is rated >90%).

Trim Rings: The PDX-series amps each have removable trim rings that can be custom painted to match your vehicle, or personalized to anything you want.

Stackable: The PDX-series amplifiers are 20% thinner than previous models at only 2" thick. A newly designed stacking system packs the amps closer together so there are no gaps and to save space in the trunk while directly coupling the amps heatsinks to help share cooling duties. The stacking plates are included with other PDX-series amplifiers.

Note: 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 indicator glows blue when the amplifier is turned on.


Hidden Controls: The Alpine PDX amplifier's controls are hidden behind a decorative front panel. The front panel is removed by unscrewing one machine screw with the supplied Allen wrench and then prying the front panel open.

Gain Control: The PDX-V9 provides independent rotary controls for the front, rear, and sub channels to set the amplifier's gain according to the level of the incoming signal. The gain settings is continuously variable from 0.2V to 4.0V for the front and rear and 0.1V to 4.0V for the sub.

Optional Remote Bass Control: The amplifier has an RJ-25 modular jack for adding the optional RUX-KNOB Remote Bass Control for full control of the bass adjustments from the dash. You can also control multiple amps from the same controller with simple telephone cord adapters.

Note: The Remote Bass Control will only control the mono subwoofer channel (channel 5).

Crossovers: The Alpine PDX-V9 offers independent crossovers for the front, rear, and sub channels, which can be set as follows:

  • Front (High-pass only): 3-way switch (Off, x1, x10); Frequency: 30-600Hz (x1) or 300-6000Hz (x10)
  • Rear: 3-way switch (Off, HP, LP); Frequency: 30-600Hz (HP) or 300-6kHz (LP, if front switch set to x10); CH3/4 Input Switch (1/2 or 3/4)
  • Sub: Frequency: 50-600Hz (LP), 3-30Hz (Subsonic); SubW Input Switch (1+2+3+4 or SubW)


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

Quick Connect Plugs: The PDX series amplifier uses quick connect plugs to attach your system's speaker wires and power cables to the amp for a simple, error-free installation.

Quick Connect Speaker Terminals: The Alpine PDX-V9 includes 5 quick connect high-power speaker terminals. Bare speaker wire, up to 8 gauge, is held in place by screw clamps on the quick connectors. The speaker terminal quick connectors then plug into the amplifier.

Quick Connect Battery Terminals: The removable battery terminal quick connector features a low-loss, high-current design. It accepts up to 4GA wire for power and ground, to ensure your amp gets the power it needs while allowing for easy installation. The remote-turn on lead will accept up 12 gauge wire. The power, ground, and remote-turn on lead are secured by set-screws on quick connector. The battery terminal quick connector then plugs into the amplifier.

Line Level Input: The Alpine PDX-V9 is equipped with six gold-plated female RCA jacks.

Fuses: The Alpine PDX-V9 is equipped with two 40-amp ATC fuses.

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.

Staff Reviews

Product reviews from the Crutchfield Labs

The Alpine PDX-V9 is the 5-channel version of their popular PDX amps. It's small, stackable with other PDX amps, and gives you serious power, with a tiny footprint.

What are the Labs?
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

1 amp does all, including sub [ scott  Mar 05, 2017 ]
Work with technic pnp harness for my Bmw 07 328i hifi system [ Mahdi  Jun 02, 2016 ]
BADASS [ GREG  Mar 20, 2016 ]
I hate spending money twice, I'm to poor to be buying things over and over so I rather get the right stuff and be done with it. [ FIDEL  Feb 02, 2016 ]

14 questions already asked

The higher resistance of the 8 Ohm sub will get about half the rated 4 Ohm wattage so; around 250 RMS. I hope that helps! My Bio: [ Ryan  Apr 20, 2017 ]  Staff
No, you need like 1000 watt amp. I love the 5 ch pdx, but it is only like 250 watts, not goona do much for a w7 [ austin building  Mar 02, 2017 ]
I forgot to tell you I am powering the same sub with a sundownaudio 1500RMS at 1 ohm, currently on a two ohm load feeding 800 watts to the sub. Perfect match [ Daril  Jan 15, 2017 ]
Normally you want to stay over 75% of your subwoofer RMS. This sub is rated at 750watts RMS not 1000, misleading information from alpine. RMS is 4 times less the max power in this case 3000. With this amp rated at 500 you are only providing 67% of your sub rated RMS (750) and while it would thump I would get a bigger amp. The reason for this is because when you underpower a sub, trying to get louder you will send clipped signal. It is always better to get an amp either rated the same as the sub or more, that way you will have more room left letting your amp work cooler and insuring your signal is clear. [ Daril  Jan 15, 2017 ]
Yes it'll run fine and sound good, but will get a good amount louder and sound great if you put 1000 rms to it. [ JAROD  Jan 13, 2017 ]
Yes you can run the sub at 2 ohm and the door speakers at 4 ohm, that is exactly what I did, i ran 4 alpine type r 61/2" @ 4ohm and a alpine type r 8" sub 2 ohm. [ austin building  Dec 26, 2016 ]
No I returned this for a fosgate t 1000 4 chanel to do that. Happy new year [ RICHARD  Dec 26, 2016 ]
inputs are RCA only. Manual does not say anything about speaker inputs. [ JOSEPH M  Oct 24, 2016 ]
This setting means the High Pass filter frequency cut off, so if really depends on what channels you are running on this output and what speakers. If the speakers have their own crossovers simply leave it off or set it to a high value to protect the speakers from blowing at high volume. [ Dominic  Sep 27, 2016 ]
This amp would not run 2 shallow subwoofers that have the RMS watt range you listed. Each subwoofer would get 250 watts and that's lower than the 300 minimum that you indicated your subwoofers need. But we have amps that can and shallow subwoofers that will run on this amp. Feel free to call an advisor on 1-800-324-9695 for a personal recommendation! My Bio: [ Paul  Aug 12, 2016 ]  Staff
Well mine is running a set of kicker comps 12 and 2 sets of Polk miss and tweets sounds good but if your looking uber bump it's not the amp you want [ johnathan  Mar 15, 2016 ]
It can move rms 500 watts on 4 and 2 ohm on the sub channel...I have an alpine type-r 15" hooked up and it hits really nice [ Homer  Mar 14, 2016 ]
Enter an answerI would do the following assuming you have front and rear full range speaker locations in your car. - Will you want to use the fader in the factory head unit? If so, then run the Audiocontrol unit off the front OEM speaker channels to the PDX-V9, and run the rear speaker channels in stock connection configuration like nothing was added. - If you run it this way, then you would run two main RCA channels from the Audiocontrol to the PDX-V9, then using the selectable input switches on the PDX, run 4 + 1 channel out to the Polk mids, tweets, and JL subwoofer. All 4 channels will provide a dedicated 100W RMS to each midrange and each tweeter. - This would eliminate the need for the passive crossover that came with the Polks. That is normally fine as passive crossovers from the lower price point speaker sets are nothing special. The active crossover in the Alpine PDX-V9 will provide better sound quality and more precise tuning over crossover points and gain settings. The only disadvantage is you will not know the EXACT crossover points. For this, you will need an o-scope or RTA meter to measure where the roll off frequencies will be. For starters, shoot for somewhere in the 3-4K range for low pass midrange and high pass tweeters. I tried looking up the crossover values built into your Polks, but could only find the -12dB value and not the frequency. - For the subwoofer channel, you have two choices: 1) Run the RCA "bass" channels from the Audiocontrol to the subwoofer channel input on the Alpine. This way, you can play with the "Accubass" to see if it is worth the hype. 2) Ignore the RCA "bass" channels from the Audiocontrol and have the Alpine control all bass functions. If so, I HIGHLY recommend investing $30-$50 for the RUX-KNOB. It easily mounts anywhere and uses a phone cable to connect to an input port on the PDX-V9. When plugged in, it overrides the gain control for the sub channel and allows you to adjust subwoofer volume on the fly. to this question. [ Craig  Jan 19, 2016 ]
I had mine professional installed, I'm not sure how they set it up. Sorry I couldn't be of more assistance. [ jeff  Jan 12, 2016 ]
Well if externally from the amp there is a crossover from the woofer to tweeter I would run that off the amp...basically the amp has 5 channels a front left/right a rear left/right and a sub channel each output 100watts...if your only running the 2 speakers off the amp with the sub I would just bridge 1-4 to make only 2 channel output and hook the speakers up that way...the speakers will handle the power and you'll just have to make sure you don't over gain the long as you don't over gain you won't be over feeding the speakers...also depending on the size of your Polk speakers you may want to set the crossover for them off the amp because it will make the music clearer...I would not run a separate channel to the tweeters because the crossover doesn't cover the ranges you need to cut low levels out also you would need a way to feed signal the same as the other speaker so you would need an rca splitter...all that being should just bridge and run to the speakers with an in-line crossover between the woofer and tweeter and make sure you adjust your gain settings correctly [ Homer  Jan 12, 2016 ]
I would use one channel per component speaker (woofer and tweeter) because the RMS rating is for the entire component speaker system not for each individual component (i.e tweeter + woofer + crossover = RMS). [ Christopher  Jan 11, 2016 ]
I had it professionally installed, I didn't hook it up. [ jeff  Feb 03, 2015 ]
Dosen't matter, the amp internally adjusts the polarity to be correct. The only thing I did to be consistent was to put all the plugs the same way. Don't think it mattered, was more of an ocd thing. [ Brian  Feb 02, 2015 ]
They go either way didn't matter this is a killer little amp it learns to power what way you plug them in really. Neat amp it will get louder as you go [ johnathan  Jan 31, 2015 ]
Either way, the negative makes its connection on the outside of the plug. [ Christopher  Jan 31, 2015 ]
It does not matter which way you put the plugs in i put all mine + up...i dont even think it matters if they all go the same direction but to be safe i would put all in the same direction [ Homer  Jan 31, 2015 ]
It doesn't matter as long as you match your positive wire to the + and the negative wire to the - . The outside of the plug supplies one of the signals while the inside of the plug supplies the other. Similar to how RCA cables work. If your truly interested in which signal goes where, use a continuity tester. [ TODD  Jan 31, 2015 ]
It doesn't matter. The Amp will auto-sense the polarity once the connector is attached to the Amp. Just connect everything with everything off. [ CHRISTOPHER  Jan 31, 2015 ]
That's the nice thing about these amps. They can be plugged in either way without any problems.. I don't remember which way I did mine, but they're all facing the same way just to look nice. [ Kevin  Jan 31, 2015 ]
I use 14g for the speaker wire and 10g for the sub wire. [ LAURA  Jun 28, 2014 ]
I had it installed at a shop, i don't know what size wire they used. I don't know what the lowest gauge wire the amp will accept. [ jeff  Jun 25, 2014 ]
4 ga [ DOYLE  Jun 25, 2014 ]
I just bought this and i do believe i am running 8 gauge to my sub from on...the holes for each speaker output are pretty big and should handle 6 gauge maybe 4 [ Homer  Jun 25, 2014 ]
You can use 14 gauge easy . I have even used 8 gauge on mono amp for speakers and the plugs are the same for the whole PDX line [ PAUL  Jun 25, 2014 ]
4 gauge [ johnathan  Jun 24, 2014 ]
We have not received any answers from other customers on your question. I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They should be able to help answer your question. [ Jeff  May 01, 2014 ]  Staff