Introduction
The MIDIPLUS X4 III is a 49-key MIDI keyboard controller, part of the 3rd generation X series. Designed for musicians and producers, it features a full-size, velocity-sensitive keyboard, along with a comprehensive set of controls including knobs, buttons, and touch strips for pitch and modulation. This manual provides detailed instructions for setting up, operating, and maintaining your X4 III controller to ensure optimal performance and a seamless creative workflow.

Figure 1: Overview of the MIDIPLUS X4 III MIDI Keyboard Controller. This image displays the full 49-key layout, along with the control knobs, buttons, and touch strips located above and to the left of the keys.
Setup Guide
Package Contents
- MIDIPLUS X4 III MIDI Keyboard Controller
- USB Type-B Cable
Connecting Your Controller
The X4 III connects to your computer via a standard USB Type-B cable, which also provides power. It is compatible with both Windows PC and Mac operating systems.
- Connect one end of the supplied USB Type-B cable to the USB port on the rear of the X4 III controller.
- Connect the other end of the USB cable to an available USB port on your computer.
- The controller will power on automatically. Your operating system should recognize the device without requiring additional drivers.

Figure 2: Rear panel connections of the X4 III. This image shows the MIDI OUT port, USB Type-B port, Sustain pedal input (SUS), and Expression pedal input (EXP).
Optional Connections
- MIDI OUT Port: Connect to external MIDI hardware using a standard MIDI cable.
- Sustain Pedal Port (SUS): Connect a standard sustain pedal (not included) for piano-style sustain.
- Expression Pedal Port (EXP): Connect an expression pedal (not included) for continuous control over parameters.
Operating Your Controller
Key Features and Controls
- Velocity-Sensitive Keys: The 49 full-size keys respond to how hard you play, allowing for expressive dynamics.
- 4 Knobs: These assignable knobs can control various parameters in your Digital Audio Workstation (DAW) or software instruments.
- 6 Buttons: Dedicated transport control buttons for your DAW (e.g., Play, Stop, Record).
- Octave & Transport Buttons: Adjust the keyboard's octave range and control DAW transport functions.
- Pitch and Modulation Touch Strips: Provide dynamic control over pitch bend and modulation effects. These are illuminated to indicate activity.

Figure 3: Close-up view of the illuminated Pitch and Modulation touch strips, along with the Octave and Transpose buttons. These controls allow for expressive manipulation of sound.
- X Knob: A multi-function knob for controlling DAW and software instrument parameters, or for adjusting keyboard settings.
- Display: Provides real-time feedback on control information and current settings.

Figure 4: Detailed view of the X knob and the digital display, which provides visual feedback for various settings and parameters.
Advanced Functions
The X4 III supports various advanced configurations accessible directly from the keyboard:
- Program Change (default): Send program change messages to switch sounds on connected devices.
- Mackie Control (default) & HUI: Support for industry-standard control protocols for deep integration with DAWs like Avid Pro Tools.
- CC Mode: Assign Continuous Controller (CC) numbers to knobs, buttons, and touch strips.
- Bank MSB/LSB Setting: Configure Bank Select messages for accessing larger sound libraries.
- Smart Scale Setting: Access built-in smart scales, including Chinese pentatonic, Japanese scale, and Blues scale, to assist with melodic composition.
- MIDI Channel: Adjust the MIDI channel for communication with other MIDI devices.
Maintenance
To ensure the longevity and optimal performance of your MIDIPLUS X4 III, follow these simple maintenance guidelines:
- Cleaning: Use a soft, dry cloth to wipe down the surface of the controller. For stubborn dirt, slightly dampen the cloth with water. Avoid using abrasive cleaners, solvents, or waxes, as these can damage the finish.
- Dust Protection: When not in use, cover the keyboard with a dust cover to prevent dust and debris from accumulating on the keys and controls.
- Storage: Store the controller in a cool, dry place away from direct sunlight, extreme temperatures, and high humidity.
- Handling: Always handle the controller with care. Avoid dropping it or subjecting it to strong impacts.
Troubleshooting
If you encounter issues with your MIDIPLUS X4 III, refer to the following common troubleshooting steps:
- No Power/No Lights:
- Ensure the USB cable is securely connected to both the controller and your computer.
- Try a different USB port on your computer.
- If using a USB hub, ensure it is powered.
- Not Recognized by Computer/DAW:
- Verify the USB cable connection.
- Restart your computer and the DAW software.
- Check your DAW's MIDI settings to ensure the X4 III is enabled as an input device.
- For Windows, check Device Manager; for Mac, check Audio MIDI Setup to confirm the device is recognized.
- Keys/Controls Not Responding:
- Ensure the correct MIDI channel is selected on both the controller and your DAW/software instrument.
- Verify that the controller is sending MIDI data (some DAWs have MIDI monitor features).
- Perform a factory reset if available (refer to the full product manual for specific instructions, if applicable).
- Unexpected Behavior:
- Ensure your DAW and operating system are up to date.
- Check for any firmware updates for the X4 III on the Midiplus official website.
If problems persist after attempting these steps, please contact Midiplus customer support for further assistance.
Specifications
| Model Name | X4III |
| Number of Keys | 49 |
| Key Type | Full-size, Velocity Sensitive |
| Controls | 4 Knobs, 6 Buttons, Pitch & Modulation Touch Strips, X Knob, Octave & Transport Buttons |
| Connectivity | USB Type-B, MIDI OUT, Sustain Pedal Input (SUS), Expression Pedal Input (EXP) |
| Compatible Devices | Windows PC, Mac Computer |
| Supported Software | Avid Pro Tools (and other standard DAWs) |
| Material Type | Plastic |
| Color | White |
| Product Dimensions | 7.6 x 30.79 x 3.43 inches (193 x 782 x 87 mm) |
| Item Weight | 6.6 pounds (3.5 kg) |

Figure 5: The MIDIPLUS X-series family, showcasing the X4 III alongside its larger counterparts, the X6 III and X8 III, illustrating the range of available models.
Warranty and Support
For information regarding warranty coverage and technical support for your MIDIPLUS X4 III MIDI Keyboard Controller, please refer to the warranty card included with your product or visit the official Midiplus website. You can also contact Midiplus customer service directly for assistance with product registration, troubleshooting, or service requests.
For the latest drivers, firmware updates, and additional resources, please visit the Midiplus support page.





