Clarion DPX1851

Mono subwoofer car amplifier — 850 watts x 1 at 2 ohms

  • Clarion DPX1851


  • Clarion DPX1851


  • Clarion DPX1851

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Item #: 020DPX1851

Review Summary

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Our take on the Clarion DPX1851

by Buck Pomerantz

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.

Clarion unleashes the power of your music with their high-tech DPX Series amps, which combine the efficiency of digital signal processing with the fidelity of analog power delivery. The DPX1851 will satisfy your appetite for big servings of bass — it'll deliver an immense 850 watts into a 2-ohm load, driving your sub setup powerfully.

The built-in "Precise Frequency Selector" low-pass crossover offers exacting control over the amp's output, so your subs play cleanly and efficiently, handling only the notes for which they were designed. Meanwhile, a variable subsonic filter helps you get even cleaner sound by keeping out the inaudible ultra-low notes that your subs would otherwise waste effort trying to reproduce.

In addition to the preamp inputs, speaker-level inputs let you add a DPX amp to just about any system, including your factory stereo. Dedicated circuitry on the inputs keeps things pure by reducing the likelihood of extraneous noise.

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  • mono subwoofer car amplifier
  • 460 watts RMS x 1 at 4 ohms (850 watts RMS x 1 at 2 ohms)
  • Precise Frequency Selector variable low-pass filter (30-230 Hz, 24 dB/octave)
  • variable bass boost (0-15 dB at 30-125 Hz)
  • variable subsonic filter (10-80 Hz)
  • CEA-2006 compliant
  • preamp and speaker-level inputs
  • gold-plated connector terminals
  • requires external mounting of a 100-amp fuse (not included)
  • 4-gauge amp wiring kit recommended — wiring and hardware not included with amplifier
  • 14-5/16"W x 2-3/8"H x 10-1/16"D
  • warranty: 2 years
  • Our 60-day money-back guarantee

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

Features and Specs
RMS Power Output (Watts x Channels) 460 x 1
Peak Power Output (Watts x Channels) 850 x 1
Power at 2 Ohms (Watts x Channels) 850 x 1
Bridged Power (Watts x Channels) ---
Minimum Impedance Bridged ---
Minimum Impedance Unbridged 2
Best Frequency Response 10-230 H Hz
THD at Rated RMS Power 1%
Signal to Noise Ratio 68 dB
Input Voltage 14.4v
Amplifier Class GH
Low-Pass Crossover Frequency 30-230 Hz
Low-Pass Slope (dB/octave) 24 dB
High-Pass Crossover Frequency N/A
High-Pass Slope (dB/octave) N/A
Bass Boost 0-15 dB
Bass Boost Frequency 30-125 Hz
Fan Cooled No
Fuse Rating 90 (not included)
Speaker Level Inputs Harness
Preamp Outputs No
Width (inches) 14-5/16
Height (inches) 2-3/8
Depth (inches) 10-1/16
Parts Warranty 2 Years
Labor Warranty 2 Years
Product Research
What's in the box?

Download owner's manual

  • Mono amplifier
  • 12" Speaker level input harness
  • 4 Self-tapping screws (length=3/4")
  • 4 Speed clips
  • Owner's manual (Eng/Fren/Span)

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.



Class GH Amplifier: The Clarion DPX1851 is a Class GH amplifier, which gives you the efficiency of a Class D amplifier with the sound quality of a Class AB amp.

CEA-2006 Compliant: CEA-2006 is a system of testing and measurement methods for mobile audio amplifiers. This voluntary standard advocates a uniform method for determining an amplifier's RMS power output and signal-to-noise ratio. The criteria for measuring power uses a DC input voltage of 14.4 volts and the RMS power output is measured into a 4-ohm load, with 1% or less Total Harmonic Distortion (THD) plus noise at 20Hz to 20,000Hz. CEA-2006 allows consumers to compare car amplifiers and receivers on an equal basis. Using the CEA-2006 standard, the DPX1851 is rated at 460 watts x 1 @ 4 ohms, and 880 watts x 1 @ 2 ohms. Clarion also publishes a more conservative power specification of 850 watts x 1 @ 2 ohms.

Operating Level Switch: A two-way switch lets you set the nominal operating level of the amplifier from 0.2 to 8V for the RCA inputs, or 500mV to 5V for the speaker-level inputs. Once you have set the correct operating level, you can then set the gain control.

Gain Control With Input Voltage Selector: This DPX-series amplifier accommodates a wide range of signal input voltages (0.2V to 8V). This wide range is split up into three ranges, which are accessible through an Input Voltage Selector switch and rotary gain dial. Depending upon the input source, you can select 0.2V to 0.6V, 0.6V to 2V, or 2V to 8V, using the 3-way switch on the left side of the amplifier. The gain rotary control operates within these voltage windows.

Note: Most decks, even 4V and 5V units, do not operate at full output voltage. Most decks will require the switch to be set in the 0.6V to 2V range.

Low-Pass Filter: The Clarion DPX1851 amplifier includes a continuously variable 30-230 Hz crossover to filter out the highs from your subwoofer. The filter has a 24 dB/octave slope.

Note: The low-pass filter is not defeatable.

Bass Boost: The amplifier features a bass boost circuit with adjustable frequency and variable level control. The Bass Boost control lets you tune low-frequency audio response to compensate for a less than ideal subwoofer enclosure design. You can select a center frequency between 30 Hz and 125 Hz, and adjust the boost from 0 dB to 15 dB.

Subsonic Filter: The DPX1851 has an adjustable subsonic filter designed to eliminate extremely low frequencies which rob power and can damage subwoofers. You can select a cutoff frequency between 10 Hz and 80 Hz.

Stackable Design: Multiple DPX1851 amplifiers can be daisy-chained together, and all controlled on one master amplifier's control panel. The amp has an additional pair of RCA jacks which are used for "Slave Out" and "Slave In" connections. Each amp's Input Source switch should be set to indicate whether the source is the head unit (Normal) or another amp (Slave). In a daisy-chained configuration, each amplifier can independently control separate speaker loads, assuming the phase switch on all amplifiers is set the same.

External Bridging: You can use two DPX1851s to power one speaker (4Ω load minimum) through external bridging. In this configuration, the positive terminals are both connected to the load and the negative terminals to each other. The master amp is set to normal phase while the slave amp is set out of phase.

Protection Circuitry: The amplifier has a three-way protection circuitry. The amplifier will shut down when the operating temperature is too high, during over voltage and when the speaker outputs are shorted. A red LED on the left side of the amplifier glows when the amp has shut down and is in protection mode.

Aluminum Heat Sink: The DPX1851 utilizes an aluminum heat sink for efficient heat dissipation so the amplifier stays cool during operation.

Soft Start Turn-On: The amplifier's remote turn-on lead features "Soft Start" which mutes the amplifiers output during turn-on to prevent any turn-on thump.

Speaker-level and Line-level Inputs: The amp provides both line-level and speaker-level inputs. If connecting a receiver with line outputs, you can use an RCA stereo patch cable. If the receiver does not have line outputs, you can splice the supplied high-level speaker input harness to the receiver's left and right speaker wires, then plug the harness into the amplifier.

Gold-plated Terminals: The DPX1851 features gold-plated connections, including the set-screw terminals for power, ground, remote, and speakers, as well as the RCA line inputs. These gold-plated terminals prevent corrosion and provide excellent signal transfer. The RCA inputs also feature ground loop isolation to help prevent noise from entering your system.

Wiring Recommendation: The DPX1851 does not have a built-in fuse, nor does it come with a fuse. According to the manual, this amplifier has a 90-Amp fuse rating. It is recommended that a 4-gauge amplifier wiring kit be used with the included 100-Amp fuse.


Left Side:

  • High Input: 5-pin plug-in clip for use with the supplied high-level speaker input harness
  • Low Input: 1 pair of stereo RCA inputs
  • Slave In/Out: 1 pair of RCA jacks: Slave In (white), Slave Out (red)
  • Remote Level: RJ-25 jack (6-pin modular phone jack) for use with optional BC-2 remote bass control module (item # 020BC2)

Right Side:

  • GND (ground): set-screw terminal (accepts up to 4-gauge wire)
  • REM (remote turn-on): set-screw terminal (accepts up to 8-gauge wire)
  • +12V (power): set-screw terminal (accepts up to 4-gauge wire)
  • Speaker Terminals: 1 pair of gold-plated set-screw terminals
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Clarion DPX1851 Reviews

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5 out of 5

Holy Moly

Written By tookeyed, Mountain View, Ca on Saturday, August 15, 2009
Crutchfield Customer Review (What's this?)
Wow, i hooked this thing up to 2 12" pioneer champions single voice coil each rated at 400w and my system is SLAPPIN HARD!! This amp did its job and i picked it up for a great price. The only trouble i had was in the wiring, which had nothing to do with the product, but it was the first time I wired an amp, took two hours but wiring is the hardest part, plugging it in and mounting it is easy. Anyways, I love this amp. The best deal around for 850watts.
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5 out of 5

Great Value!

Written By Jose, Deep South Texas on Monday, August 10, 2009
Crutchfield Customer Review (What's this?)
I actually biught this amp on impulse since the price was so good. I'm sure glad that I did. I originally wanted to push a single 12" [MTX TR5512] with this thing, but due to all sorts of crazy circumstances I ended up with this setup.

1 x DPX1851

2x 12" 12v.3 [DVC 2ohm]

Q-Logic "Type-2" ported/sealed box [Ported for testing]

This thing really pushes these subs really nicely, I was surprised how good that it sounds and how hard it bumps. I can't wait to break in the subs properly so I can really start pushing them hard. Do NOT hesitate to get this amp, it's a super deal.
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5 out of 5

Excellent sub driver!

Written By CeeKay, North Dakota... on Sunday, August 09, 2009
Crutchfield Customer Review (What's this?)
This amp makes my 12" pound like a jackhammer! It's a bit underpowered compared to the sub's recommended power numbers, but you wouldn't notice a difference.

Have yet to feel any heat from it, but then again the entire bottom plate is a fan-cooled heat sink...

For the price, this amp is a STEAL!!!

- CK
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5 out of 5

Great Amp for the $

Written By DFA82, Fayetteville, NC on Tuesday, June 23, 2009
Crutchfield Customer Review (What's this?)
I hooked this up to a 12in DVC Kicker Classic and a 1.2 fard in my 09 Civic si and this thing is awsome. At first I was kinda worried about the class of the amp but this thing runs cool and isnt' loud at all. It has a nice clean look to it and has alot of features. I purchased it on sale so I got a great deal for 850W@2
1 out of 1 people found this helpful
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5 out of 5

2005 Jeep Grand Cherokee(Limited)NAV

Written By Joe, Michigan on Monday, June 08, 2009
Crutchfield Customer Review (What's this?)
This amplifier literally hooked right up to my stock Boston acoustics system and it makes the Infinity Kappa 10.1 that its attached to sound great. The amp, though i have it hidden away, is very aesthetically pleasing and the lights fit the style and the brushed aluminum top is really slick. It runs pretty cool and i haven't heard any glitches in my bass frequencies its a real solid design. I recommend this amplifier to any audio enthusiast as a supplement to their car stereo system.
8 out of 10 people found this helpful
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