JL Audio MX500/4 Owner's Manual
This manual provides information for the JL Audio MX500/4 4-Channel Full-Range Amplifier.
Specifications and Configurations
The MX500/4 amplifier supports various configurations:
- 4 Stereo Outputs (non-fading): 2CH Mode, uses Front Inputs only, 70W x 4 @ 4Ω (125W x 4 @ 2Ω).
- 4 Stereo Outputs (fading): 4CH Mode, uses Front and Rear Inputs, 70W x 4 @ 4Ω (125W x 4 @ 2Ω).
- 2 Bridged Mono Outputs: 2CH Mode, uses Front Inputs only, 250W x 2 @ 4Ω.
- 2 Stereo Front + 2 Mono Rear Outputs: 3CH Mode, uses Front Inputs only, 70W x 2 @ 4Ω (125W x 2 @ 2Ω).
- 2 Stereo Front + 1 Bridged Mono Rear Output: 3CH Mode, uses Front Inputs only, 70W x 2 @ 4Ω (125W x 2 @ 2Ω) + 250W x 1 @ 4Ω.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Amplifier doesn't turn on | Faulty fuse | Remove fuse and check with continuity meter. Replace if necessary. |
| Intermittent output, fluctuates when I tap on it or hit a bump | Poor connection integrity | Check "+12V", "Ground", and "Remote" leads for pinched wires; ensure tight connections. |
| Insufficient "Remote" input | Poor connection integrity | Make sure there is a sufficient +12V supply at the "Remote" connection; if not a relay may be required. |
| Distorted, attenuated, or popping sound | Faulty speaker connection (Short Circuit/Over Current Protection) | Inspect speaker wires for possible short-circuit, either together or shorted to the vehicle's chassis ground. Check the nominal load impedance at the amplifier is equal to or greater than 2 ohms stereo (4 ohms bridged). |
| Output shuts off after a while | Overheating condition (Thermal Protection) | Make sure amplifier mounting area has adequate space for ventilation and heat dissipation. |
Appendix A: Input Sensitivity Level Setting
This section details how to set the input sensitivity for maximum, low-distortion output using a digital AC voltmeter and a sine-wave test tone CD/file.
Necessary Equipment:
- Digital AC Voltmeter
- CD or file with a sine-wave test tone (0 dB reference level) in the frequency range to be amplified (50 Hz for subwoofers, 1 kHz for midrange).
Nine-Step Procedure:
- Disconnect speakers from amplifier output connectors.
- Turn off all processing (bass/treble, loudness, EQ, etc.) on source unit, processors, and amplifier. Set source unit's fader to center and subwoofer level to 3/4 maximum.
- Turn "Input Sens." control fully down.
- Set source unit volume to 3/4 of full volume.
- Determine target voltage from the chart based on speaker impedance.
- Verify speakers are disconnected. Play appropriate sine wave at 3/4 source unit volume.
- Connect AC voltmeter to amplifier speaker output connectors (+ and -).
- Increase "Input Sens." control until target voltage is observed.
- Reconnect speakers. Adjust "Input Sens." downward if needed for system balance.
Important Notes:
- Do not increase "Input Sens." beyond the maximum level set during this procedure to avoid distortion and speaker damage.
- If equalizer boost is activated after setting "Input Sens.", re-adjustment may be necessary. EQ cuts do not require re-adjustment.
Target AC Voltage Chart:
| Nominal Impedance | Target AC Voltage |
|---|---|
| 4Ω | 16.7 V |
| 2Ω | 15.8 V |
| Bridged to 4Ω | 31.6 V |
Limited Warranty - Amplifiers (USA)
JL Audio warrants this product for two (2) years from the original date of purchase against defects in materials and workmanship. This warranty is non-transferable and applies only to the original purchaser from an authorized JL Audio dealer.
Warranty Coverage: JL Audio will repair or replace defective products with new or remanufactured product at no charge.
Not Covered: Accident, misuse, abuse, product modification, neglect, failure to follow installation instructions, unauthorized repair attempts, misrepresentations by the seller. Incidental or consequential damages, cost of removal/reinstallation, and cosmetic damage are not covered.
Warranty Void: If the product's serial number has been removed or defaced. Implied warranties are limited to the duration of the express warranty.
Service Information:
- All warranty returns must be sent freight-prepaid through an authorized JL Audio dealer with proof of purchase.
- Direct returns from consumers without authorization will be refused.
- Warranty expiration without proof of purchase will be based on the manufacturing date code.
- Non-defective items will be returned freight-collect. Customer is responsible for shipping charges and insurance.
- For Service Information in the U.S.A., call JL Audio Customer Service at (954) 443-1100 (9:00 AM – 5:30 PM Eastern Time).
- JL Audio, Inc. Address: 10369 North Commerce Pkwy., Miramar, FL 33025 (Do not send product for repair to this address).
International Warranties: Products purchased outside the United States are covered by the country's distributor, not JL Audio, Inc.
