JL Audio XDM500/3
500W 3-CHANNEL AMPLIFIER
OWNER'S MANUAL
Featuring NexD™ Switching Technology
Installation Considerations
Proper installation requires appropriate tools and safety equipment. Professional installation is recommended.
- Before installation, turn off the audio system and disconnect the battery.
- Install the product in a dry, well-ventilated location that does not interfere with factory-installed systems.
- Do not install in the engine compartment, areas of extreme heat, or where directly exposed to the elements.
- Before cutting or drilling, check for potential obstacles behind mounting surfaces.
- Carefully route all system wiring away from moving parts and sharp edges. Secure with cable ties or wire clamps, and use grommets and loom where appropriate to protect from sharp edges.
This manual is also available in French, Spanish, German, and Italian.
Safety Considerations
- Only use this product with 12-volt, negative-ground electrical systems. This product is not certified or approved for use in aircraft.
- Mount this product securely to prevent damage or injury in severe conditions.
- An appropriate fuse (or circuit breaker) at the main power wire is vital for vehicle/vessel safety and must be installed within 18 inches (45 cm) of the positive battery connection.
- For ABYC and NMEA applications, circuit protection is required within 7 inches (18 cm) of the battery, unless the cable is in an enclosure or conduit.
- Listen to your audio system at levels appropriate for operating conditions and hearing safety.
Connections
The amplifier features various connection terminals for power, ground, remote activation, audio inputs, and speaker outputs.
Diagram shows the amplifier's rear panel with numbered connection points for power, ground, remote, inputs, and outputs. Included accessories like a 2.5 mm Allen wrench and mounting screws are also depicted.
| Point | Connection | Description | Notes |
|---|---|---|---|
| 1 | +12VDC | Positive (+12V) Power Connection | 4 AWG wire required. Install 50A fuse at (+) battery post. |
| Ground | Negative (GND) Ground Connection | 4 AWG wire required. 18-12 AWG wire capacity. | |
| 2 | Remote | Positive (+12V) Activation Connection | See Turn On Mode for more info. Accepts 200mV-4V input voltage. |
| CH. 1 Input | Left Input Signal, Black RCA | ||
| CH. 2 Input | Right Input Signal, Red RCA | ||
| SUB CH. Input | Left Subwoofer Input Signal, Black RCA | See Input Mode for more info. | |
| SUB CH. Input | Right Subwoofer Input Signal, Red RCA | ||
| Preout 1 | Left Pass-Through Preamp Signal, Black RCA | See Preouts From for more info. | |
| Preout 2 | Right Pass-Through Preamp Signal, Red RCA | ||
| 3 | Remote Level Control | Remote Level Controller Connection (optional) (HD-RLC or MHD-RLC) | Operates as an attenuator only: Fully counter-clockwise = Level Muted; Fully clockwise = Level Unaffected. |
| 4 | CH. 1 (L) Speaker Output | (+) Positive Speaker Output | Minimum impedance load: Stereo mode ≥2 ohms, Bridged mode ≥4 ohms. 16-8 AWG wire capacity. |
| (-) Negative Speaker Output | |||
| CH. 2 (R) Speaker Output | (+) Positive Speaker Output | ||
| (-) Negative Speaker Output | |||
| CH. 1&2 Bridged (+) | (+) Positive Speaker Output | Both positive (+) connections are connected in parallel internally. Both negative (-) connections are connected in parallel internally. Minimum impedance load: ≥2 ohms. 16-8 AWG wire capacity. | |
| CH. 1&2 Bridged (-) | (-) Negative Speaker Output | ||
| 5 | Mono Subwoofer Output | (+) Positive Subwoofer Output | Minimum impedance load: ≥2 ohms. 16-8 AWG wire capacity. |
| (-) Negative Subwoofer Output |
Controls
The amplifier features several controls for configuration and tuning.
Diagram shows the amplifier's top panel with numbered control sections for LEDs, Turn-On Mode, Input Filter, Input Mode, Remote Level, Preouts, and Input Sensitivity.
Status LED (6)
- Flashing Green: Amplifier powering up, audio output muted.
- Green: Normal operation, active audio output.
- Red: Safe Mode, Over-Temperature Condition, Audio Output Reduced. Returns to normal when temperature stabilizes.
- Amber (yellow): Safe Mode, Over-Current Condition, Audio Output Muted. May exhibit repetitive ticking or thumping. Inspect for short circuits or low impedance.
- LEDs Off: Amplifier turns off due to Low-Voltage Condition (below 10V). Returns to normal when voltage rises above 11V.
Turn On Mode (7)
Configures the activation method:
- +12V Remote Turn-On: Preferred method, controlled by switched +12V or source unit's turn-on output.
- DC Offset-Sensing (Automatic): Turns on when a small DC signal is detected in OEM audio outputs and off when removed.
- Signal-Sensing (Automatic): Turns on when full-range OEM audio signals are detected and off after a delay.
Input Filter (7)
Configures input filter application:
- Car: For most automotive and marine installations.
- Boat: Select if experiencing interference from high-current mechanical switches/devices.
Input Mode (7)
Configures input signal connections:
- 2 Ch.: Uses CH. 1 & 2 inputs only. SUB CH. signal is sum of CH. 1 & 2.
- 4 Ch.: Uses all four inputs. SUB CH. signal is sum of both left and right SUB CH. inputs. A Y-adapter is recommended if only one subwoofer signal is available.
Remote Level Mode (Optional) (7)
Configures HD-RLC operation:
- All: Adjusts level of all channels equally.
- Sub: Adjusts level of subwoofer channel only.
Preouts From (7)
Configures preamp output signals:
- 1&2: Same signal as CH. 1&2 inputs.
- Sub: Same signal as subwoofer channel inputs.
- Sum: Combined signal from CH. 1&2 and subwoofer channels.
Input Sens. (Input Sensitivity) (8)
Adjusts the input stage for each channel pair to match source unit output voltage with amplifier inputs. Refer to Appendix A for detailed information.
HP Filter Mode (CH. 1&2) (8)
Configures the high-pass filter for channels 1 & 2:
- Off: Filter defeated; passes full range of frequencies.
- HP: Attenuates frequencies below the set cutoff frequency at 12dB/octave.
HP Filter Freq. (Hz) (CH. 1&2) (8)
Adjusts the high-pass filter cutoff frequency for channels 1 & 2 (50 Hz-500 Hz / 12dB per octave).
LP Filter Mode/Slope (SUB CH.) (8)
Configures the low-pass filter and slope for the subwoofer channel:
- Off: Filter defeated; passes full range of frequencies.
- 12dB: Attenuates frequencies above the set cutoff frequency at 12dB/octave.
- 24dB: Attenuates frequencies above the set cutoff frequency at 24dB/octave.
LP Filter Freq. (Hz) (SUB CH.) (8)
Adjusts the low-pass filter cutoff frequency for the subwoofer channel (50 Hz-500 Hz / 12dB per octave).
Appendix A: Input Sensitivity Level Setting
Follow these steps to adjust the input sensitivity of each amplifier channel pair for overall system balance.
Necessary Equipment
- Digital AC Voltmeter
- Sine-wave test tone recorded at 0 dBfs reference level (1 kHz for full range, 50 Hz for subwoofer).
Nine-Step Procedure
- Disconnect speaker(s) from amplifier output connectors.
- Turn off all processing (bass/treble, loudness, EQ, etc.) on source unit, processors, and amplifier. Set fader to center and subwoofer level to 3/4 maximum.
- Turn all "Input Sens." controls fully down.
- Set source unit volume to 3/4 full volume.
- Determine target voltage from the chart below based on speaker system impedance.
- Verify speakers are disconnected. Play test tone at 3/4 source unit volume.
- Connect AC voltmeter to amplifier speaker output terminals (measure one channel for stereo, correct terminals for bridged).
- Increase "Input Sens." control until target voltage is observed.
- Reconnect speakers. Adjust "Input Sens." controls downward if amplifier attenuation is needed for system balance.
IMPORTANT: Do not increase "Input Sens." beyond the maximum level established during this procedure to avoid audible distortion and speaker damage. Re-adjust "Input Sens." if any equalizer boost is activated after setting.
Chart shows Nominal Impedance (8Ω, 4Ω, 3Ω, 2Ω) and Target AC Voltage for CH 1&2 (Stereo), CH 1&2 (Bridged), and Subwoofer CH.
Specifications
Amplifier Section
- Amplifier Topology: NexD™ Ultra-High Speed Class D
- Power Supply Type: Unregulated MOSFET Switching
- Minimum Copper Wire: 4 AWG (CCA not recommended)
- Recommended Fuse: 50 A
- Rated RMS Power @ 14.4V, <1% THD+N: Main @ 4Ω (75W x 2), Main @ 2Ω (100W x 2), Main @ 4Ω Bridged (200W x 1), Sub @ 4Ω (180W x 1), Sub @ 3Ω (240W x 1), Sub @ 2Ω (300W x 1)
- Rated RMS Power @ 12.5V, <1% THD+N: Main @ 4Ω (60W x 2), Main @ 2Ω (90W x 2), Main @ 4Ω Bridged (180W x 1), Sub @ 4Ω (180W x 1), Sub @ 3Ω (240W x 1), Sub @ 2Ω (300W x 1)
- Frequency Response: Main Channels (12 Hz-22 kHz ±0.5 dB), Sub Channel (10 Hz-1 kHz ±0.5 dB)
- S/N Ratio (A-weighted): Main Channels (>104 dB), Sub Channel (>103 dB)
- Damping Factor: Main Channels (>150 @ 50 Hz), Sub Channel (>120 @ 50 Hz)
Input Section
- Number of Inputs: 4 (Two Stereo Pairs)
- Input Type: Differential-Balanced with RCA jack inputs
- Input Voltage Range: 200mV-4V RMS
Signal Processing
- Filter Type (CH. 1&2): Active, 12dB/octave, High-Pass (50-500 Hz), defeatable
- Filter Type (SUB CH.): Active, 12dB or 24dB/octave, Low-Pass (50-500 Hz), defeatable
Remote Level Control
- Compatibility: HD-RLC or MHD-RLC (optional). Full mute to 0 dB range.
Dimensions
- LxWxH: 10.23 in. x 7.09 in. x 2.05 in. (260 mm x 180 mm x 52 mm)
