Introduction
The beyerdynamic MMX 300 (2nd Generation) is a closed stereo headset designed for gaming and multimedia applications. It combines studio sound quality with clear speech transmission and high comfort, making it suitable for extended use. This manual provides essential information to help you get the most out of your headset.

Image: The beyerdynamic MMX 300 headset, featuring its black design, comfortable earcups, and integrated microphone.
What's in the Box
Upon unboxing your MMX 300 headset, verify that all components are present:
- beyerdynamic MMX 300 Headset
- 1.2 m (3.9 ft) cable for console use
- 2.5 m (8.2 ft) cable for PC use
- 6.35 mm Jack Adapter
- DT Hardcase (carrying case)

Image: An overhead view displaying the beyerdynamic MMX 300 headset alongside its included accessories: a 1.2m console cable, a 2.5m PC cable, a 6.35mm jack adapter, and a hardcase.
Setup
The MMX 300 headset features a detachable cable system for versatile connectivity.
- Cable Selection: Choose the appropriate cable for your device. Use the 1.2m cable for consoles (Xbox One, PS4, Mobile) or the 2.5m cable for PC.
- Connecting the Cable: Insert the smaller end of the chosen cable into the port on the left earcup of the headset. Ensure it is securely twisted into place to prevent accidental disconnection.
- Connecting to Device:
- For PCs with separate audio and microphone jacks, use the 2.5m cable which splits into two 3.5mm jacks (one for audio, one for microphone).
- For consoles or mobile devices with a single combined 3.5mm jack, use the 1.2m cable.
- If connecting to an audio interface or amplifier requiring a larger connection, use the included 6.35mm jack adapter.
- Initial Audio Configuration: After connecting, ensure your device's audio settings recognize the headset. Adjust volume levels and microphone input sensitivity as needed within your operating system or game settings.

Image: A close-up view of the beyerdynamic MMX 300 headset, emphasizing its solid construction and the removable cable connection point on the earcup.
Operating Instructions
The MMX 300 is designed for intuitive use and comfort during long sessions.
Wearing the Headset
Place the headset over your ears, ensuring the earcups fully enclose them. The headband is adjustable to fit various head sizes. The silky-soft velour ear pads and comfortable headband padding contribute to extended wearing comfort.

Image: A detailed view of the MMX 300's earcup, highlighting the silky-soft velour ear pads, which are exchangeable for user preference and hygiene.

Image: An overhead perspective of the MMX 300 headset, showcasing the comfortable headband padding and the high-quality materials used in its construction.
Microphone Usage
The MMX 300 features a high-quality microphone capsule for excellent speech intelligibility. Position the microphone boom arm so that the microphone is near your mouth, typically about 1-2 inches away, for optimal voice pickup. The boom arm is flexible for easy adjustment.
Volume Control
Volume adjustments are typically managed via the inline remote control on the cable (for PC cable) or through your connected device's system volume settings.

Image: A person wearing the beyerdynamic MMX 300 headset while using a laptop outdoors, demonstrating comfortable use in a casual setting.

Image: A user from behind, wearing the MMX 300 headset and holding a game controller, focused on a large screen displaying a video game, illustrating its use for console gaming.
Maintenance
Proper care will extend the lifespan of your MMX 300 headset.
- Cleaning: Use a soft, dry cloth to clean the surfaces of the headset. For the velour ear pads, gentle brushing or a lint roller can remove dust. Avoid using harsh chemicals or abrasive cleaners.
- Storage: When not in use, store the headset in its included DT Hardcase to protect it from dust, spills, and physical damage.
- Cable Care: Avoid sharp bends or excessive pulling on the cables. The detachable design allows for easy replacement if a cable becomes damaged.
- Ear Pad Replacement: The velour ear pads are exchangeable. Over time, they may show wear or accumulate dirt. Replacement ear pads can be purchased from authorized beyerdynamic retailers.
Troubleshooting
This section addresses common issues you might encounter with your MMX 300 headset.
| Problem | Possible Cause | Solution |
|---|---|---|
| No Sound or Low Volume | Incorrect cable connection, low system volume, incorrect audio output device selected. |
|
| Microphone is Quiet or Not Working | Incorrect microphone input selected, low microphone volume/boost, physical connection issue. |
|
| Headset Creaking Noise | Friction in plastic joints. | This can sometimes occur with new headsets. Gentle manipulation of the joints or continued use may reduce the noise. If persistent and severe, contact customer support. |
Specifications
| Feature | Detail |
|---|---|
| Model Name | MMX 300 |
| Connectivity Technology | Wired |
| Headphones Jack | 3.5 mm Jack |
| Noise Control | Sound Isolation |
| Frequency Range | 5 - 35,000 Hz |
| Impedance | 32 Ohm |
| Item Weight | 11.7 ounces |
| Cable Length | 8.2 Feet (PC cable) |
| Compatible Devices | PC, Xbox One, PS4, Mobile |
| Ear Placement | Over Ear |
| Material | High-quality, durable material |
| Manufacturer | Beyerdynamic, Inc. |
Warranty and Support
For detailed warranty information and technical support, please refer to the official beyerdynamic website or contact their customer service. Keep your proof of purchase for warranty claims.
You can also find additional resources and FAQs on the beyerdynamic Store on Amazon.
For a PDF version of the user guide, please visit: User Guide (PDF)





