Clarion APX280M Power System Amplifier Instruction Manual
- June 13, 2024
- clarion
Table of Contents
Clarion APX280M Power System Amplifier
INTRODUCTION
The Clarion APX280M is a full-featured two-channel amplifier incorporating the following features:
- Specially coated circuit boards, that resist mold, mildew, and moisture damage.
- Pulse-Width Modulated (PWM) MOSFET power supply for maximum performance with minimal distortion.
- Remote turn-on with “soft start” muting to prevent turn-on “thump”.
- Advanced circuitry design featuring bridgeable and mixed-mode operation for use in various system configurations.
- Variable high-pass/low-pass electronic crossover with a 12dB per octave slope (adjustable range: 55Hz to 5.5kHz).
- Variable bass boost circuit to reinforce low-frequency signals that may be lost due to subwoofer enclosure design.
- Adjustable input level controls with ground loop isolation to minimize noise and distortion.
- 2-ohm stereo stable, 4-ohm mono stable.
- Gold-plated power, speaker, and RCA connectors.
- Speaker-level input.
- Low-profile construction with aluminum heat sink for efficient heat dissipation.
ABOUT THE MANUAL AND WARRANTY
This manual describes the basic requirements to install the Clarion APX280M amplifier. The installation of this amplifier can be quite complex to install, if you do not posses the necessary knowledge and tools to perform this installation, please contact your local Clarion dealer. Keep all instructions and sales receipts for future reference and warranty information. Warranty information can be found on page 11 of this manual.
Operation/Installation
DESCRIPTION
The APX280M uses an unregulated MOSFET power supply for superior sound and output wattage. In addition, a toroid coil is used to transfer power with minimal performance loss due to heat. To avoid unwanted noise, a double-sided conformal printed circuit board with strategically placed components keeps AM RFI subdued. All of the connections and controls for the APX280M are conveniently located at the ends of the amplifier and labeled appropriately. To ensure the best possible electrical connections, the power, speaker, and RCA inputs are gold-plated. In the event of component failure or a short circuit, the APX280M incorporates safeguards and an outboard ATC fuse to prevent damage to the amplifier.
INPUT CONNECTIONS AND AUDIO CONTROLS
The front panel of the APX280M contains both connections for RCA and speaker
level inputs, along with the audio controls as shown below.
- RCA Input Jacks
- Gain Control
- Bass Boost Control
- Freq (Hz) Selection Control
- Crossover Frequency Multiplier Switch
- X-Over Mode Switch
- Input Select Switch
- Speaker Level Inputs
- Gain Control – This allows you to set the nominal operating level of the amplifier. The amplifier’s range, 250mV to 2.5V for RCA inputs or 500mV to 5V for speaker level inputs, can accommodate input levels from virtually any brand of source unit.
- Bass Boost Control- The amplifier also features a “high-Q” (i.e. narrow frequency band) Bass Boost circuit. It acts much like an equalizer, with adjustable gain (from 0 to +18dB) fixed at 45Hz. Use this feature to tune low-frequency audio response to compensate for a less-than-ideal subwoofer enclosure design. The added boost produces rich, full bass tones that are normally difficult to reproduce in the car audio environment. NOTE: If Bass Boost is undesirable, set Bass Boost to 0dB.
High-pass/Low-pass Filter Controls
-
Frequency (Hz) Selection Control – The crossover frequency is fully adjustable between 55Hz and 5500Hz (via the Crossover Frequency Multiplier) for a wide range of crossover points. Use this feature, along with your speaker manufacturer’s recommended crossover frequencies, to quickly design a more advanced system (see Applications on page 6) NOTE: If the X-Over Mode The switch is set to OFF, varying the Freq (Hz) Control will produce no effect.
-
Crossover Frequency Multiplier Switch – When engaged, this switch increases the crossover frequency by a factor of 10. Example: If the Freq (Hz) dial is set for 240 Hz, pushing in the Multiplier Switch changes the setting to 2400 Hz.
-
X-Over Mode Switch – This switch is equipped with a 12dB per octave electronic filter for precise frequency attenuation with minimal phase
distortion. The steep crossover slope keeps midrange tones out of the
subwoofer and thereby eliminates an unnatural “nasal” tone quality in the audio system. A filter is activated by sliding the X-Over Mode Switch to either LP or
HP. -
Input Mode Switch – This switch allows you to set the input mode. Stereo
input allows full left and right stereo operation. Right (bridged) input allows
single channel input for bridged operation. This is especially useful in high- powered systems when using one amplifier for each subwoofer/speaker. L + R
(sum mono) allows a stereo input to be summed into a mono output. -
Speaker Level Inputs – These provide connections for a high-level stereo source. In addition, these connections are provided for installations where the source unit’s RCA outputs are unavailable.
WARNING: When using the speaker (high-level) inputs, the Black wire must be grounded at the Radio. Failure to do this will result in noise and improper operation.
CONNECTIONS FOR POWER AND SPEAKERS
- The rear panel of the APX280M contains power and speaker connections as shown below.
- Left Speaker Output
- Right Speaker Output
- Remote Turn-on Input
- Ground Input
- Battery + 12V Input
- 25 Amp Fuse
INSTALLATION
This section suggests Mounting and Wiring Precautions for installing the Clarion APX280M amplifier. If you do not possess the necessary tools and installation experience, do not attempt to install this amplifier. Instead, contact your local Clarion dealer to perform the installation.
MOUNTING PRECAUTIONS
Prior to mounting the amplifier, make sure it is safe to mount the amplifier in that location. Failure to do so can result in serious damage to the boat. In addition, stainless steel hardware should be used to mount the amplifier and additional accessories. When possible, use a nut and bolt with a lock washer to secure the amplifier. Extra care and attention is necessary in marine installations due to the uncertainty of water conditions.
Additional precautions and suggestions
- For the most efficient cooling, mount the amplifier so cool air runs along the length of the heat sink, rather than across them. To increase air movement and circulation, a cooling fan can be installed.
- Mount the amplifier on a rigid surface; avoid mounting to subwoofer enclosures or areas prone to vibration.
- Prior to drilling and holes, make sure the proposed mounting holes will not cut into the fuel tank, fuel lines, electrical wiring, or through the boat.
- Do not mount the amplifier where it is susceptible to water.
WIRING PRECAUTIONS
Read all of the wiring precautions prior to making any connections. If you are unsure and/or don’t have the necessary installation hardware, contact your local Clarion dealer to perform the installation.
- Before you begin the installation, make sure the source unit Power switch is in the OFF position.
- Disconnect the negative (-) lead of the battery (or batteries) before making any power connections.
- When making connections, be sure that each connection is clean and secure. Insulate final connections with electrical tape or shrink tubing. Failure to do so may damage your equipment.
- A good ground is critical for the performance of the amplifier. A ground wire should be run directly from the battery to the amplifier. Use black insulated 10-gauge or larger wire for the amplifier’s ground (-) power lead.
- Add an additional fuse holder and fuse at the positive (+) terminal of the battery. The fuse rating should equal the total current consumption at full output of the amplifier(s). Use red insulated 10-gauge or larger wire for the amplifier’s positive (+) power lead. Do not install the fuse until the complete installation has been performed.
- When replacing the amplifier’s fuse, always use one having the same amperage rating. Substituting a higher-rated fuse or a slow-blow type can result in serious damage to the amplifier.
- When creating passage holes for power cables, RCA’s cords, and speaker wires, use grommets to eliminate any sharp edges created during drilling. This will protect the wire from being nicked and causing a short circuit.
- Extra cable can cause signal loss and act as an “antenna” for noise. Use only high-quality RCA cords that are no longer than necessary.
- In multiple amplifier systems, it is recommended to use a relay on the remote turn-on lead of the radio.
WIRING AND APPLICATIONS
The Clarion APX280M 2-channel marine audio amplifier can be used in a variety of system applications. Here are some examples to help plan your own installation.
Bridged – Mono Subwoofer System
Figure 4
In this application, the amplifier is bridged for mono operation to drive a
subwoofer.
2-Channel Full-Range, Satellite, or Subwoofer Stereo System (Set INPUT SELECT Switch to STEREO)
Figure 5
In this application, the amplifier is used in stereo and drives two full-range
(or satellite or subwoofer) speakers. NOTE: A passive crossover must be used
with satellite speakers.
Mixed-Mode Satellite and Subwoofer System (Set INPUT SELECT Switch to STEREO)
Figure 6
The amplifier can be configured for a mixed-mode operation. The table provides
component values to create a 6dB per octave crossover at specified
frequencies. Use components that have a + 5% tolerance and capacitors rated at
100V. NOTE: Choose the same frequency for both LP and HP crossovers. Do not
over-lap frequencies, as this may damage the amplifier.
SETTING THE GAIN
After completing the installation, follow these steps to set the Gain
Control and then perform the Final System Checks.
-
Turn the Gain Control all the way counter-clockwise.
-
Turn the vessel’s Ignition Switch to the ON position. Then turn the ON/OFF Switch on the source units to the ON position. Set all Tone or Equalization Controls to “flat” positions and turn Loudness off.
-
Play a CD or Tape and set the Volume Control at 75% of full level.
NOTE: If the system uses an equalizer, set its frequency controls to “flat” positions. -
Slowly increase the Gain Control. Stop when you hear a slight distortion of audio.
SETTING THE CROSSOVER
The Clarion APX280M features a fully adjustable crossover. To set the
crossover, follow these steps.
- Using the X-Over Mode Switch, select the desired mode – LP for Low Pass, HP for High Pass and OFF for Full Range.
- Using the Freq (Hz) Control, select the desired frequency. If the desired frequency exceeds the range of the Freq (Hz) Control, press the Crossover Frequency Multiplier Switch to increase the value by a multiplier of 10.
- For example, 55Hz x 10 = 550Hz or 550Hz x 10 = 5.5kHz.
SETTING THE BASS BOOST
- Initially set the Bass Boost control to its full left position (i.e. 0dB).
- Listen to a variety of music styles (e.g. Rock, Rap, etc.) and slowly increase the Bass Boost control until a noticeable increase in low bass response is perceived.
- Slowly adjust the Bass Boost control (up or down) to realize the best bass response.
CAUTION: If you hear a “pop” (due to speaker over-excursion), lower the Bass Boost to prevent speaker damage. If the system sounds muddy and distorted (due to amplifier clipping), lower Bass Boost to avoid shutdown from overheating.
FINAL SYSTEM CHECK
- Start the engine and turn on the source unit. After a two-second delay, slowly increase the Volume Control and listen to the audio. If you hear any noise, static, distortion, or no sound at all, check the connections, and also refer to Troubleshooting. Depending on your system design, the levels may become quite loud even at low low-volume control settings. Until you get an “audio feel” of the system’s power, use care when adjusting controls.
- Turn the Balance Controls to their extreme positions and listen to the results. Audio imaging should match control settings (audio from the left speaker when the balance is left).
- Increase the volume and verify that the amplifier reproduces audio (at full frequencies) without distortion. If you hear distortion, check the connections and verify that the Gain Control is set correctly. Another possibility is damaged speakers or under-powered speakers. Once again refer to Troubleshooting for additional help.
TROUBLESHOOTING
Problem
No Audio.
Solution
Low or no remote turn-on voltage. Check remote connections at the amplifier
and source unit. Blown amplifier fuse. Replace with new fast-blow fuse (same
rating). Power wires are not connected. Check battery and ground wiring at the
amplifier; also check battery connections. Speaker leads shorted. Check
speaker continuity to ground, it should not show a common ground. Speakers are
not connected or are blown. Check speaker connections at the amplifier, and
measure coil impedance.
Problem
Audio cycles on and off.
Solution
Thermal protection circuits are shutting the amplifier off. Check location for
adequate ventilation; consult an authorized Clarion Audio Dealer.
Problem
Distorted audio.
Solution
Gain is not set properly, or damaged speaker cones. Review Setting Gain;
inspect each speaker cone for signs of damage (i.e. frozen cone, burning
smell, etc.)
Problem
Audio lacks punch.
Solution
Speakers are wired incorrectly, which causes cancellation of bass frequencies.
Check the polarity of wires from the amplifier to each speaker as defined by
the system design.
Problem
The amplifier fuse keeps blowing.
Solution
Incorrect wiring or short circuit. Review Installation and check all wiring
connections.
Problem
Whining or ticking noise in the audio with the engine on.
Solution
The amplifier is picking up alternator noise or radiated noise. Turn down
input gain; move audio cables away from power wires. Check power and ground
connections on the amplifier; install an in-line noise filter on the source
unit’s power wire; check alternator and/or voltage regulator; test for weak
battery or add water to the battery.
PRODUCT SPECS
- Frequency Response
- 20Hz ~ 20kHz
- Signal Noise Ratio
-
100db
-
- THD
- .05% all channels driven
- Input Sensitivity Low-Level
- 250mV ~ 2.5 V
- Input Sensitivity Speaker Level
- 500mV ~ 5V
- Max. Power Output
- 320W (160Wx 2)
- Cont. Power Output
- 160W (80w x 2) @ .08% THD
- 2-Ohm Stereo Output
- 125W x 2 @ .05% THD
- Bridged Power
- 300W x 1 @ .05% THD
- Dimensions
- 2-1/8″H x 8-1/4″W x 9″ L
- Current Consumption at output @ max power
- 28A @ 382 Watts
CLARION LIMITED WARRANTY
For USA and Canada only If purchased from an authorized Clarion dealer, this product is warranted against all defects in materials and workmanship for a period of one (1) year from the date of original purchase. Clarion ProAudio products, except for speakers, are covered by a two (2) year limited warranty when purchased from and installed by an authorized Clarion dealer. ALL PURCHASES OF CLARION PRODUCTS FROM NON-AUTHORIZED CLARION DEALERS ARE SUBJECT TO FURTHER WARRANTY RESTRICTIONS AS DESCRIBED BELOW. The conditions of this limited warranty and the extent of responsibility of Clarion Corporation of America (“Clarion”) under this limited warranty are as follows :
- PROOF OF DATE OF PURCHASE WILL BE REQUIRED FOR WARRANTY SERVICE OF THIS PRODUCT. IN THE CASE OF THE TWO (2) YEAR LIMITED WARRANTY FOR CLARION PRO AUDIO PRODUCT, PROOF OF INSTALLATION BY AN AUTHORIZED CLARION DEALER IS REQUIRED. INFORMATION ABOUT CLARION-AUTHORIZED WARRANTY SERVICE CENTERS MAY BE OBTAINED BY CONTACTING OR WRITING CLARION AT THE ADDRESS LISTED BELOW.
- This limited warranty will become void if service performed by anyone other than an approved Clarion Warranty Service Center results in damage to the product.
- This limited warranty does not apply to any product that has been subject to misuse, neglect or accident, or which has had the serial number altered, defaced, or removed, or which has been connected, installed, adjusted, or repaired, other than in accordance with the instructions furnished by Clarion.
- his limited warranty does not cover car static or other electrical interferences, tape head or laser pick-up cleaning or adjustments, or labor costs for the removal or reinstallation of the unit for repair.
- The sole responsibility of Clarion under this limited warranty shall be limited to the repair of the product or replacement of the product, at the sole discretion of Clarion.
- The product must be shipped in its original carton or equivalent carton, fully insured, with shipping charges prepaid. Clarion will not assume any responsibility for any loss or damage incurred in shipping.
- CLARION PRODUCTS, INCLUDING PRO AUDIO PRODUCTS, PURCHASED FROM A SOURCE OTHER THAN AN AUTHORIZED CLARION DEALER, INCLUDING ANY AND ALL PURCHASES VIA THE INTERNET FROM A NON-INTERNET AUTHORIZED CLARION DEALER, SHALL NOT BE COVERED BY ANY CLARION LIMITED WARRANTY TO THE EXTENT ALLOWED BY APPLICABLE LAW. IN THE EVENT AND TO THE EXTENT APPLICABLE LAW PROHIBITS ELIMINATION OF WARRANTIES UNDER THESE CIRCUMSTANCES, THE APPLICABLE LIMITED WARRANTY PERIOD SHALL BE DEEMED TO BE FIFTEEN (15) DAYS FROM THE DATE OF ORIGINAL PURCHASE.
- ALL IMPLIED WARRANTIES EXCEPT TO THE EXTENT PROHIBITED BY APPLICABLE LAW SHALL HAVE NO GREATER DURATION THAN THE WARRANTY PERIOD SET FORTH ABOVE. UNDER NO CIRCUMSTANCES SHALL CLARION BE LIABLE FOR ANY LOSS OR DAMAGE, DIRECT OR CONSEQUENTIAL, ARISING OUT OF THE USE OR INABILITY TO USE THE PRODUCT. BECAUSE SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS OR EXCLUSIONS OR LIMITATIONS OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU
- THIS LIMITED WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS THAT VARY FROM STATE TO STATE.
- The laws of the State of California shall govern and control this limited warranty, its interpretation, and enforcement.
- Should you have any difficulties with the performance of this product during the warranty period, please call or visit our website for a listing of Authorized Warranty Service Centers in your area. You may also contact Clarion Customer Service at the address listed below for any service help you may need with Clarion products.
In USA:
Clarion Corporation of America Attn: Customer Service Manager 661 W. Redondo
Beach Blvd Gardena, CA.90247-4201 1-800-GO-CLARION (310)327-9100
www.clarion.com
In Canada:
Clarion Canada Inc. Warranty Service Center 2239 Winston Park Drive Oakville,
Ontario L6H 5R1 (905)829-4600
www.clarioncanada.com
References
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