Soundcraft MPMi-20 20-channel Audio Mixer User Manual

1. Introduction

This manual provides comprehensive instructions for the Soundcraft MPMi-20 20-channel Audio Mixer. It covers setup, operation, maintenance, and troubleshooting to ensure optimal performance and longevity of your device. The MPMi-20 is designed for live sound applications, offering robust features for professional audio mixing.

The Soundcraft MPMi series is known for its compact design and suitability for fixed installations, houses of worship, and portable PA systems. This model features 20 mono mic inputs, 2 stereo line inputs, and a total of up to 26 inputs to mix, along with 3 Aux sends for external effects or monitor mixes. It incorporates Soundcraft's renowned GB30 mic preamps for superior audio quality.

Figure 1.1: The Soundcraft MPMi-20 20-channel Audio Mixer in its original packaging, highlighting key features and the console layout.

2. Safety Information

Always read and understand all safety instructions before operating the mixer. Keep this manual for future reference.

• Do not expose this equipment to rain or moisture.
• Do not block any ventilation openings.
• Only use attachments/accessories specified by the manufacturer.
• Refer all servicing to qualified service personnel.
• Ensure proper grounding of the power supply.

3. Setup

3.1 Unpacking and Inspection

Carefully remove the mixer from its packaging. Inspect the unit for any signs of damage that may have occurred during transit. Retain the original packaging for future transport or storage.

3.2 Power Connection

The MPMi-20 features an integral universal power supply. Connect the supplied AC power cord to the mixer's power inlet and then to a suitable AC power outlet. Ensure the power source matches the voltage requirements specified on the mixer.

3.3 Initial Connections

Before powering on, make all necessary audio connections. The mixer includes:

• Microphone Inputs: Connect microphones to the XLR inputs. The mixer provides true, professional +48V phantom power, globally switched, for condenser microphones.
• Line Inputs: Use 1/4" TRS or TS cables for line-level sources.
• Main Outputs: Connect the main stereo mix output to your power amplifier or active speakers.
• Aux Sends: Connect these to external effects processors or monitor wedges.
• 2-Track Record Output: For connecting to a recording device.
• 2-Track Replay Input: For playing interval music from CD, MP3, or other sources.

Figure 3.1: Top-down view of the Soundcraft MPMi-20 mixer, showing the layout of all input channels, faders, and control knobs. This view helps in identifying connection points and control sections.

4. Operating the Mixer

4.1 Channel Strip Overview

Each mono input channel features:

• Gain Control: Adjusts the input sensitivity.
• 3-band EQ: With a swept Mid band for precise tone shaping.
• Aux Sends: Three auxiliary sends, globally switchable pre or post-fade.
• Pan Control: Positions the signal in the stereo field.
• Mute Button: Silences the channel.
• PFL (Pre-Fader Listen) Button: Sends the channel signal to the headphones for monitoring before the fader.
• Channel Fader: Controls the channel's level in the mix.
• Signal Present and Peak LEDs: Indicate signal presence and clipping.
• Insert Point: For connecting external signal processors to individual channels.

4.2 Mixing Basics

1. Power On: Ensure all connections are secure, then power on the mixer.
2. Set Gains: Adjust the gain control for each input channel so that the Signal Present LED illuminates consistently, and the Peak LED flashes only occasionally during the loudest parts of the signal.
3. Adjust EQ: Use the 3-band EQ to shape the tone of each instrument or vocal.
4. Set Faders: Bring up the channel faders to achieve a balanced mix.
5. Use Aux Sends: Route signals to external effects or monitor mixes using the Aux send controls.
6. Master Faders: Control the overall output level using the main stereo mix faders.

4.3 Subgroups and Monitoring

The MPMi-20 includes two subgroups, allowing for easier control of groups of channels (e.g., all drums, all vocals). Assign channels to subgroups as needed. Use the headphone output for detailed monitoring of individual channels (PFL) or the main mix.

5. Maintenance

5.1 Cleaning

Regularly clean the mixer's surface with a soft, dry cloth. Avoid using abrasive cleaners or solvents. For stubborn dirt, a slightly damp cloth can be used, followed by a dry cloth. Keep faders and knobs free from dust and debris.

5.2 Storage

When not in use, store the mixer in a cool, dry place, away from direct sunlight and extreme temperatures. If possible, use the original packaging or a dedicated flight case for protection during transport or long-term storage.

5.3 Servicing

The MPMi-20 is designed for easy servicing with vertically mounted PCBs and nutted pots for extra strength. However, all internal servicing should only be performed by qualified service personnel. Unauthorized opening of the unit may void your warranty.

6. Troubleshooting

7. Specifications

• Model: Soundcraft MPMi-20
• Channels: 20 mono Mic inputs, 2 stereo line inputs (up to 26 inputs to mix)
• Preamps: Precision GB30 mic pre-amps
• Phantom Power: True, professional +48V (globally switched)
• EQ: 3-band EQ with swept Mid band on mono inputs
• Aux Sends: 3 (globally switchable pre or post-fade)
• Groups: 2 Group busses
• Outputs: Stereo mix output, 2-track record output
• Inputs: XLR, Auxiliary (for 2-track replay)
• Power Supply: Universal internal power supply (90-240VAC, 50-60Hz)
• Dimensions: 16 x 27 x 3.7 inches (approximate, based on product dimensions)
• Weight: 12.06 pounds (approximate)
• Construction: Vertically mounted PCBs, nutted pots, rugged steel chassis

8. Warranty and Support

For warranty information and technical support, please refer to the official Soundcraft website or contact your authorized Soundcraft dealer. Keep your proof of purchase for warranty claims.

Online Resources: www.soundcraft.com

Customer Service: Refer to the contact information provided on the Soundcraft website for your region.