KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier Owner’s Manual

June 1, 2024
KICKER

KICKER Logo Owner’s Manual
KPX Amplifiers

Overview

IMPORTANT SAFETY WARNING
PROLONGED CONTINUOUS OPERATION OF AN AMPLIFIER, SPEAKER, OR SUBWOOFER IN A DISTORTED, CLIPPED OR OVER-POWERED MANNER CAN CAUSE YOUR AUDIO SYSTEM TO OVERHEAT, POSSIBLY CATCHING FIRE AND RESULTING IN SERIOUS DAMAGE TO YOUR COMPONENTS AND/OR VEHICLE. AMPLIFIERS REQUIRE UP TO 4 INCHES (10CM) OPEN VENTILATION. SUBWOOFERS SHOULD BE MOUNTED WITH AT LEAST 1 INCH (2.5CM) CLEARANCE  BETWEEN THE FRONT OF THE SPEAKER AND ANY SURFACE. KICKER PRODUCTS ARE CAPABLE OF PRODUCING SOUND LEVELS THAT CAN PERMANENTLY DAMAGE YOUR HEARING! TURNING UP A SYSTEM TO A LEVEL THAT HAS AUDIBLE DISTORTION IS MORE DAMAGING TO YOUR EARS THAN LISTENING TO AN UNDISTORTED SYSTEM AT THE SAME VOLUME LEVEL. THE THRESHOLD OF PAIN IS ALWAYS AN INDICATOR THAT THE SOUND LEVEL IS TOO LOUD AND MAY PERMANENTLY DAMAGE YOUR HEARING. PLEASE USE COMMON SENSE WHEN CONTROLLING VOLUME.
The KPX-series amplifiers have been engineered to handle the extreme conditions of powersports and outdoor audio applications, provide massive amounts of power, and continue to be cutting-edge efficient, making them perfect for less robust charging systems. Use with any combination of KICKER products, whether powersports speakers, full-range speakers, or KICKER’s classic aftermarket speakers. And don’t let the small, weather resistant footprint fool you; this amp came to play.

Specifications

Model: KPX500.1 KPX300.4
Dynamic Power 750W 350W

RMS Power Output
@ 14.4V, 4Ω stereo, ≤ 1% THD+N
@ 14.4V, 2Ω stereo, ≤ 1% THD+N
@ 14.4V, 4Ω mono, ≤ 1% THD+N
@ 14.4V, 2Ω mono, ≤ 1% THD+N
@ 14.4V, 1Ω mono, ≤ 1% THD+N| 150W X 1
300W x 1
500W x 1| 45WX4
75WX4
150WX 2
Frequency Response [Hz]| 10Hz – 160Hz| 20Hz – 20kHz
Selectable Electronic Crossover| 24dB/Octave, Variable
Lo-Pass 40–160 Hz| 12d B/Octave
Hi-Pass 60/80/120 Hz
KickEQ™ Bass Boost| Selectable 0/+6db
Bass Boost @ 40 Hz| N/A
Fader On/Off Switch| N/A| Yes
Subsonic Filter| 24dB/Octave, Variable
Hi-Pass 10–40Hz| N/A
Remote Bass Control| Yes, CXARC (Not Included)| N/A
Length [in, cm]| 8 1/2, 21.7| 8 1/2, 21.7
Height [in, cm]| 1 11/16, 4.3| 1 11/16, 4.3
Width [in, cm]| 3 5/8, 9.2| 3 5/16, 8.4
Signal-to-Noise Ratio [dB]| >90dB, a-weighted, re: rated power
Signal-to-Noise Ratio [dB]| >75dB (ref: 1 W output)
Input Sensitivity| Low Level: 125mV-5V
High Level: 1V-40V

Note: All specifications and performance figures are subject to change. Please visit www.kicker.com for the most current information. To get the best performance from your new KICKER amplifier, we recommend using genuine KICKER speakers, accessories and wiring.
Pro Tip: A that’s eft are PowerSports speakers , and a few cables , and you’ll have an audio upgrade that will dominate any factory system! KICKER amplifiers make it easy to upgrade to solid bass with your existing or stock source unit. Ask your dealer about KICKER upgrades.

Installation

Mounting
Choose a structurally sound location to mount your KICKER amplifier. Make sure there are no Items behind the area where the screws will be driven, Choose a location that allows at least 4” (10cm) of open ventilation for the amplifier. Drill four holes using a 7/64” (8mm) bit and use the supplied #8 screws to mount the amplifier.KICKER 51KPX300.4 Compact All Weather 4
Channel Amplifier - Installation

Power Wiring
Click Here for Amolifier Install Kits

Model| External Fuse (sold separately)| Power/Ground Wire| KICKER Wiring Kit
---|---|---|---
KPX300.4| 1 x 40 Ampere| 8 Gauge| KMPKB, PKB, CKB

KICKER will provide a three-year warranty with all KPX-Series Amplifier purchases paired with a qualifying KICKER Installation Kit*.
U.S.A ONLY
1 YEAR WARRANTY EXTENSION
This extends the standard warranty by an additional year. Amplifier and Kit must be purchased from an Authorized KICKER Dealer.
Using poor-quality, under-spec wiring kits will impede KPX amplifier performance.
A superior-quality KICKER installation Kit is guaranteed to extend the life of KPX amplifiers.
The new extended warranty applies only to KICKER amplifiers and accessories sold to consumers by Authorized KICKER Dealers in the United States of America or its possessions. It also only applies to the original purchaser of KICKER amplifiers and accessories. One warranty extension per amplifier is allowed regardless of the number of amplifier installation kits purchased. This program does not apply to “B”- stock product or factory-refurbished product. This offer is for a limited time, so see your local Authorized KICKER Dealer soon for details.
*U.S.A. Only | EE.UU. solamente | Nur USA | Les USA SeulementKICKER
51KPX300.4 Compact All Weather 4 Channel Amplifier - Installation
2

Install the KPX Power & Ground Terminal Adapter to begin. Disconnect the vehicle’s battery to avoid an electrical short. A good ground connection Is important. If the KPX Is mounted In the front fairing of a motorcycle, it will be best to extend the ground wire all the way to tne battery. Make the ground wire short, 24″ (60cm) or less and, if not conneted to the battery, connect it to a paint-and-corrosion-free, solid metal area of the vehicle’s chassis. Adding an additional ground wire of this same gauge (or larger) between the battery’s negative post and the vehicle chassis is recommended. Keep the audio signa cable negative post and the vehicle chassis is recommended. Keep the audio signal cable away from factory wiring harnesses and other power wiring. If you need to cross this wiring, cross It at a 90 degree angle. Install a fuse at the blue +12V constant wire. Fuse installation should be as close as possible to the battery, and no further than 18” (45cm) of the battery, and in-line with the harness’ power cable, which is connected to your KPX Amplifier. Make sure the power wire is routed so that it will not be damaged, crimped, or shorted. If you ever need to remove the amplifier from the vehicle after it has been installed, the ground wire should be the last wire disconnected from the amplifier; just the opposite as when you installed it.KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier - Installation
3

For multiole amplifier installations where distribution blocks are used, each amplifier should have its proper-rated fuse, or breaker, installed between the amplifier and the distribution block within eighteen inches of the block, or on the distribution block if it provides for fusing. The primary power wire should also be fused between the battery and distribution block, within eighteen inches of the battery’s positive terminal, with a fuse or breaker rated at least to the sum of the individual amplifiers fuse values, but doesn’t exceed the capacity of your wiring.KICKER 51KPX300.4 Compact All
Weather 4 Channel Amplifier - Installation 4KICKER 51KPX300.4 Compact All Weather 4 Channel
Amplifier - Installation 5If needed, cut off the RCA connections to use hi- eve input, or use the KICKER KISL Speaker-RCA Converter.

Speaker Wiring
(4-Channel Operation)KICKER 51KPX300.4 Compact All Weather 4 Channel
Amplifier - Installation 6

(Bridged Operation)![KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier

Operation

IMPORTANT: First switch has no function. Never change the switches with the audio system on!KICKER 51KPX300.4 Compact All Weather 4 Channel
Amplifier - Operation

Automatic Turn-On: The KPX-series offers two different automatic turn-on modes; +12V and DC Offset.

  • Remote Turn-On: Run 18 gauge wire from the Remote Turn-On Lead on your source unit to the blue REM wire on the KPX amplifier’s wiring harness.
  • DC Offset Turn-On: The DC Offset mode detects a >2.5V DC offset from the Hl-Level speaker outputs when the source unit has been turned on.

Input Gain Controls: The inout gain control is not a volume control. It matches the output of the source unit to the input level of the amplifier. Maximum power out of the amplifier is possible with the gain in the lowest position. Incorrectly setting the gain can result in distorted output or damage to, and premature failure of, your speakers.
For a quick setup, turn the source unit up to about 3/4 vo ume (if the source unit goes to 30, turn it to 25). S ow y turn up (clockwise) the gain on the amplifier until you can hear audible distortion, then turn it down a little.
To use the preferred method of setting the input gain using a vo tmeter or osci oscope, begin by turning off the amp ifier and disconnecting all speakers from it. Turn the gain knob completely off (counterclockwise) and all crossovers off, or to their least effective setting. If a remote bass accessory is connected to the amplifier, turn it completely on (clockwise). Ensure all EQ and DSP settings on the source unit such as bass, treble, fader, seating position etc are set to linear, flat, center, or off. Turn on the amplifier. Play a 0dB sine wave through your source unit and increase the volume to about 3/4 of maximum. Sine wave tracks can be downloaded for free from KICKER.com under the “Support” tab.
Use the 50Hz sine wave to set the gain for a subwoofer and the 1kHz sine wave for full-range speakers. Set your voltmeter or oscilloscope to measure AC voltage. Place the voltmeter’s probes on the amplifier’s speaker output terminals. With the sine wave playing, slowly turn the gain knob clockwise and watch the AC voltage on the voltmeter increase.
When the desired voltage is shown (reference power chart at KICKER.com), or you start to see the waveform square off stop increasing the gain, turn the amplifier off, reconnect all soeakers and set the crossovers to your desired setting. Your gain is now set for maximum unclipped power from the amplifier. If you increase amplitude using settings on the source unit or the bass boost on the amplifier it will introduce distortion and you will need to redo these steps.

KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier - Operation
2 Fader Switch: Turn the fader switch ON if you are running two sets of inputs (front and rear for example) to the amplifier. Leave the fader switch OFF if you want to drive all channels from a single stereo input.
Input Level: Choose whether to receive a HI or LO-level signal from your source unit.
HI-PASS: Use the HI-PASS switches of the amplifier to set the internal crossover.
Choose a cutoff of GOHz, 8OHZ, 120HZ, or OFF depending on the configuration of switches.

Troubleshooting

If your amplifier does not appear to be working, check the obvious things first such as blown fuses, poor or incorrect wiring connections, incorrect setting of crossover switch and gain controls, etc. There are Power (PWR) & Protection (PRT) LEDs on the side  panel of your KICKER KPX series amplifier. Depending on the state of the amplifier and the vehicle’s charging system, the LEDs will glow either green or red. When the green LED is lit, this indicates the amplifier is turned on and no trouble exists.
Green LED off, no output? With a Volt Ohm Meter (VOM) check the following: 1 + 12 volt power terminal (should read + 12V to + 16V) 2 Remote turn-on terminal (should read + 12V to +16V) 3 Check for reversed power and ground connections 4 Ground terminal, for proper conductivity.
Green LED on, no output? Check the following: 1 RCA connections 2 Test speaker outputs with a “known” good speaker. 3 Substitute source unit with a “known” good source unit. 4 Check for a signal in the RCA cable feeding the amplifier with the VOM meter set to measure “AC” voltage.
Red (PRR) LED flickering with loud music? The red (PRT) LED indicates low battery voltage. Check all the connections in your vehicle’s charging system. It may be necessary to replace or charge your vehicle’s battery or replace your vehicle’s alternator.
Red (PRT) LED on, no output? 1 Ampilifier is very hot = thermal protection is engaged.
Test for proper impedance at the speaker terminals with a VOM meter (see the diagrams in this manual for minimum recommended impedance and multiple soeaker wiring Suggestions).
Also check for adequate airflow around the amplifier. 2 Amplifier shuts down only while vehicle is running = voltage protection circuitry is engaged. Voltage to the amplifier is not within the 6-16 volt operating range. Have the vehicle’s charging and electrical system inspected. 3 Amplifier will only play at low volume levels = short circuit protection is engaged.
Check for speaker wires shorted to each other or to the vehicle chassis. Check for damaged speakers or speaker(s) operating below the minimum recommended impedance.
No or low output? 1 Check the balance and fader controls on source unit. 2 Check the RCA (or speaker input) and speaker output connections. 3 lf using a Low-Level signal, make sure Radio Detect is OFF. 4 Check the volume level on your source unit, to include the volume level of any connected phones or MPG players.
Alternator noise-whining sound with engine’s RPM? 1 Check for damaged RCA (or speaker input) cable 2 Check the routing of RCA (or speaker input) cable 3 Check the source unit for proper grounding 4 Check the gain settings and turn them down if they are set too high.
CAUTION: When jump starting the vehicle, be sure that connections made with jumper cables are correct. Improper connections can result in blown amplifier fuses as well as the failure of other critical systems in the vehicle.
If you have more questions about the installation or operation of your new KICKER product, see the Authorized KICKER Dealer where you made your purchase. For more advice on installation, click on the SUPPORT tab on the KICKER homepage, www.KICKER.com.
Choose the TECHNICAL SUPPORT tab, choose the subject you are interested in, and then download or view the corresponding information.
Please E-mail support@KICKER.com or call Technical Services 405-624-8583 for unanswered or specific questions.

Warranty

When purchased from an Authorized KICKER Dealer, KICKER warrants this product to be free from defects in material and workmanship under normal use for a period of TWO (2) YEARS from date of original purchase with receipt. If this product is identified as “Refurbished” or “B Goods”, the warranty is limited to a period of THREE (3) MONTHS from the date of original purchase. In all cases you must have the original receipt. Should service be necessary under this warranty for any reason due to manufacturing defect or malfunction during the warranty period, KICKER will repair or replace (at its discretion) the defective merchandise with equivalent merchandise. Warranty replacements may have cosmetic scratches and blemishes. Discontinued products may be replaced with more current equivalent products. This warranty is valid only for the original purchaser and is not extended to owners of the product subsequent to the original purchaser. Any applicable implied warranties are limited in duration to a period of the express warranty as provided herein beginning with the date of the original purchase at retail, and no warranties, whether express or implied, shall apply to this product thereafter. Some states do not allow limitations on implied warranties; therefore, these exclusions may not apply to you. This warranty gives you specific legal rights; however you may have other rights that vary from state to state.
WHAT TO DO IF YOU NEED WARRANTY OR SERVICE:
Defective merchandise should be returned to your local Authorized Stillwater Designs (KICKER) Dealer for warranty service. Assistance in locating an Authorized Dealer can be found at www.KICKER.com or by contacting Stillwater Designs directly. You can confirm that a dealer is authorized by asking to see a current authorized dealer window decal.
If it becomes necessary for you to return defective merchandise directly to Stillwater Designs (KICKER), call the KICKER Customer Service Department at 405-624-8510 for a Return Merchandise Authorization (RMA) number. Package only the defective items in a package that will prevent shipping damage, and return to:
Stillwater Designs
3100 North Husband St
Stillwater, OK 74075
The RMA number must be clearly marked on the outside of the package. Please return only defective components. The return of functioning Items increases your return freight charges. Nondefective items will be returned freight collect to you. For example, if a subwoofer is defective, only return the defective subwoofer, not the entire enclosure. Include a copy of the original receipt with the purchase date clearly visible, and a “proof-of-purchase” statement listing the Customer’s name, Dealer’s name and invoice number, and product purchased. Warranty expiration on items without proof-of-purchase will be determined from the type of sale and manufacturing date code. Freight must be prepaid; items sent freight-collect, or COD, will be refused.

WHAT IS NOT COVERED?
This warranty is valid only if the product is used for the purpose for which it was designed. It does not cover:

  • Damage due to improper installation
  • Subsequent damage to other components
  • Damage caused by excessive heat, chemical cleaners, and/or UV radiation
  • Damage through negligence, misuse, accident or abuse. Repeated returns for the same damage may be considered abuse
  • Any cost or expense related to the removal or reinstallation of product
  • Speakers damaged due to amplifier clipping or distortion
  • Item previously repaired or modified by any unauthorized repair facility
  • Return shipping on non-defective items
  • Products with tampered or missing barcode labels
  • Products with tampered or missing serial numbers
  • Products returned without a Return Merchandise Authorization (RMA) number
  • Products purchased from an UNAUTHORIZED dealer
  • Freight Damage
  • The cost of shipping product to KICKER
  • Service performed by anyone other than KICKER

HOW LONG WILL IT TAKE?
KICKER strives to maintain a goal of one week turnaround for all electronics (amplifiers, crossovers, equalizers, etc.) returns.
Delays may be incurred if lack of replacement inventory or parts is encountered. Failure to follow these steps may void your warranty.
Any questions can be directed to the KICKER Customer Service Department at 405-624-8510. Contact your International KICKER dealer or distributor concerning specific procedures for your country’s warranty policies.
Contact your International KICKER dealer or distributor concerning specific procedures for your country’s warranty policies.
Our goods come with guarantees that cannot be excluded under the Australian Consumer Law.
You are entitled to a replacement or refund for a major failure and for compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.
P.O. Box 459
Stillwater, Oklahoma 74076
USA
(405) 624–8510

KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier - Logo
150KPX-d-240125

KPX300.4 AMPLIFIER
Info Card
IMPORTANT:
KICKER recomrnerds a professional installation performed by authorizoo retailers . You are solely responsible for safely mounting and wiring your prodocts.
If you have a problem with this product, prior to returning the product to the store,
Contact KICKER Tech Support
Call us at 800-256-KICK (5425), or contact us at support@kicker.com with any questions or problems.
Thank you for your LICKER purchase!
U.S. Customers Only
Scan here for owner’s manual

https://qr.kicker.com/g/3vOV9qIfmxl

Thank you and congratulations on your purchase of the KICKER KPX300.4 Amplifier! The KPX-series have been engineered to handle the extreme conditions of power sports and outdoor audio applications, provide massive amounts of power, and continue to be cutting-edge efficient, making them perfect for less robust charging systems. Use with any combination of KICKER products, Whether powersparts speakers, full-range speakers, or KICKER’s classic after market speakers. And don’t let the small, weather proof footprint fool you; this amp came to play
Sincerefy
Steve Irby
President/CEO IMPORTANT SAFETY WARNING! PROLONGED CONTINUOUS OPERATION OF AN AMPLIFIER, SPEAKER, OR SUBWOOFER IN A DISTORTED, CLIPPED, OR OVER-POWERED MANNER CAN CAUSE YOUR AUDIO SYSTEM TO OVERHEAT, POSSIBLY CATCHING FIRE AND RESULTING IN SERIOUS DAMAGE TO YOUR COMPONENTS ANDYOR VEHICLE. AMPLIFIERS REQUIRE UP TO 4 INCHES (10CM) OPEN VENTILATION.
SUBWOOFERS SHOULD BE MOUNTED WITH AT LEAST 1 INCH (2.5CM) CLEARANCE BETWEEN THE FRONT OF THE SPEAKER AND ANY SURFACE. KICKER PRODUCTS ARE CAPABLE OF PRODUCING SOUND LEVELS THAT CAN PERMANENTLY DAMAGE YOUR HEARING! PLEASE USE COMMON SENSE WHEN CONTROLLING VOLUME.

Wiring

Model| External Fuse
(sold separately)| Power/ Ground Wire| KICKER Wiring Kit
---|---|---|---
KPX300.4| 1 x 40 Ampere| 8 Gauge| KMPK8, PK8, CK8

KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier -
WIRINGKICKER 51KPX300.4
Compact All Weather 4 Channel Amplifier - WIRING 2See owner’s manual for information on how to use amplifier features such as Remote Tum-on, crossovers, and more!

KICKER Logo51Kpx4-c23

Documents / Resources

| KICKER 51KPX300.4 Compact All Weather 4 Channel Amplifier [pdf] Owner's Manual
51KPX300.4, 51KPX300.4 Compact All Weather 4 Channel Amplifier, Compact All Weather 4 Channel Amplifier, Weather 4 Channel Amplifier, 4 Channel Amplifier, Amplifier
---|---

References

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>

Related Manuals