Audio System M850.1D Monobloc Amplifier Instruction Manual

1. Introduction

This manual provides detailed instructions for the installation, operation, and maintenance of your Audio System M850.1D monobloc amplifier. The M850.1D is a high-performance 1-channel amplifier designed for car audio systems, featuring efficient SMD technology and stable operation down to 2 ohms. Proper installation and understanding of its features will ensure optimal performance and longevity of the unit.

2. Safety Information

Always disconnect the vehicle's negative battery terminal before beginning any installation.
Ensure all wiring is properly routed and secured to prevent damage or short circuits.
Use appropriate gauge power and ground wires as specified for the amplifier's power output.
Install the amplifier in a location that allows for adequate ventilation to prevent overheating.
Avoid installing the amplifier in areas exposed to moisture or excessive vibration.
Consult a professional car audio installer if you are unsure about any aspect of the installation process.

3. Setup and Installation

Careful installation is crucial for the performance and safety of your amplifier. Follow these steps for proper setup.

3.1 Mounting the Amplifier

Select a secure, well-ventilated location for mounting the amplifier. Ensure there is sufficient space around the unit for airflow, especially around the top-mounted fan. Use the provided mounting hardware to secure the amplifier firmly to a solid surface in the vehicle.

Audio System M850.1D Monobloc Amplifier, top-down view

Figure 1: Top-down view of the Audio System M850.1D monobloc amplifier, showing its compact design and heat sink fins.

3.2 Power Connections

GND (Ground): Connect this terminal to a clean, unpainted metal surface of the vehicle chassis. Ensure a solid electrical connection. The ground wire should be as short as possible.
+12V (Power): Connect this terminal directly to the positive terminal of the vehicle's battery. An in-line fuse (not supplied) of appropriate rating must be installed within 18 inches (45 cm) of the battery.
REM (Remote Turn-On): Connect this terminal to the remote output of your head unit. This signal turns the amplifier on and off with your car's audio system.

3.3 Speaker Connections

Connect your subwoofer(s) to the SPEAKER terminals. The M850.1D is a monobloc amplifier, designed for a single channel output. Ensure the total impedance of the connected speakers is not below 2 ohms for stable operation.

3.4 Signal Input

The amplifier supports both RCA (low-level) and high-level inputs.

RCA Input: Connect RCA cables from your head unit's pre-out to the RCA INPUT jacks on the amplifier.
High-Level Input with Auto-On: If your head unit does not have RCA pre-outs, you can use the high-level input. Connect the speaker output wires from your head unit directly to the high-level input terminals. The amplifier features an automatic turn-on function when using high-level input, eliminating the need for a separate remote wire.

Audio System M850.1D Monobloc Amplifier, connection panel

Figure 2: Rear view of the Audio System M850.1D amplifier, showing the power, speaker, and input connections, along with control knobs.

4. Operating and Adjustments

Once installed, adjust the amplifier settings for optimal sound performance.

4.1 Control Panel Overview

Refer to Figure 2 for the location of the following controls:

REMOTE: Connection for the wired remote control (RTC) for bass level adjustment.
LOW PASS (LPF): Variable low-pass filter (30-150 Hz). Adjust this to control the upper frequency limit of the subwoofer.
SUBSONIC: Subsonic filter (10-50 Hz / 24 dB). This filter removes ultra-low frequencies that are inaudible and can damage subwoofers.
BASS BOOST: Adjustable bass boost (0-6 dB at 45 Hz). Use this to enhance low-frequency output.
PHASE: Phase adjustment (0-180°). Adjust this to ensure the subwoofer's output is in phase with the rest of the audio system.
LEVEL (Gain): Input sensitivity control. Adjust this to match the output voltage of your head unit. Start with the lowest setting and gradually increase until desired volume is achieved without distortion.
INPUT MODE: Switch for selecting input type (e.g., Low/High).

4.2 Initial Setup Procedure

Set all amplifier controls (LPF, Subsonic, Bass Boost, Phase, Level) to their minimum or off positions.
Turn on your head unit and set its volume to about 75% of maximum.
Slowly increase the amplifier's LEVEL (gain) control until you hear slight distortion, then back off slightly.
Adjust the LPF to blend the subwoofer with your main speakers (typically between 60-100 Hz for subwoofers).
Adjust the SUBSONIC filter to protect your subwoofer from very low, damaging frequencies (e.g., 20-30 Hz).
Experiment with the PHASE control to find the setting that provides the most impactful bass.
Use the BASS BOOST sparingly, as excessive boost can cause distortion and damage.
Utilize the wired remote control (RTC) for convenient bass level adjustment from the driver's seat.

5. Maintenance

The Audio System M850.1D amplifier requires minimal maintenance. Regular checks can help ensure its longevity.

Periodically inspect all wiring connections for tightness and corrosion.
Keep the amplifier clean and free of dust and debris. Use a soft, dry cloth for cleaning. Do not use liquid cleaners.
Ensure the cooling fan and heat sink fins are not obstructed to maintain efficient heat dissipation.

6. Troubleshooting

If you experience issues with your amplifier, consult the following troubleshooting guide before seeking professional assistance.

Problem	Possible Cause	Solution
No Power / Amplifier does not turn on	Blown fuse (in-line or internal) Poor power or ground connection No remote turn-on signal Faulty wiring	Check and replace fuses. Verify all power and ground connections are secure. Ensure remote wire is connected and receiving +12V when head unit is on. Inspect all wiring for breaks or shorts.
No Sound Output	Input signal issue Speaker wiring incorrect or shorted Gain setting too low Amplifier in protection mode	Check RCA or high-level input connections. Verify speaker wiring for correct polarity and no shorts. Increase the LEVEL (gain) control. Check speaker impedance; ensure adequate ventilation.
Distorted Sound	Gain set too high Speaker impedance too low Poor ground connection Damaged speakers	Reduce the LEVEL (gain) control. Verify speaker impedance is within amplifier's limits (min 2 ohms). Ensure ground connection is solid. Test speakers with another amplifier if possible.
Amplifier Overheating	Insufficient ventilation Speaker impedance too low Excessive gain or bass boost	Relocate amplifier or improve airflow. Check speaker impedance. Reduce gain and bass boost settings.

7. Specifications

Technical specifications for the Audio System M850.1D monobloc amplifier.

Model: M850.1D
Channels: 1 (Monobloc)
RMS Power Output (14.4V):
- 1 x 500 W RMS @ 4 Ohms
- 1 x 800 W RMS @ 2 Ohms
Frequency Response: 10 Hz – 150 Hz
Low Pass Filter (LPF): 30 – 150 Hz
Subsonic Filter: 10 – 50 Hz / 24 dB
Bass Boost: 0 – 6 dB @ 45 Hz
Phase Adjustment: 0 – 180°
Input Type: RCA (Low-Level) and High-Level with Auto-On
Voltage: 14.4 Volts (Operating)
Dimensions (L x H x W): Approximately 295 x 50 x 185 mm
Cooling: Top-mounted fan, efficient cooling system
Special Features: SMD technology, Wired Remote Control (RTC) included

8. Warranty and Support

Specific warranty terms and conditions for the Audio System M850.1D amplifier are typically provided with the product packaging or available from the point of purchase. For technical support or service inquiries, please contact your authorized Audio System dealer or visit the official Audio System website.