The single-sided Sennheiser HMD 301 PRO-X4F is a closed-back, circumaural communications headset offering detailed, linear response, switchable ActiveGard hearing protection, and a detachable XLR 4-pin female cable. The headset features comfortable construction with split-headband padding to remove pressure from sensitive areas of the head.

With a frequency response of 60 Hz to 25 kHz, the headphones provide clear reproduction of audio, doing so while offering up to 32 dB of passive noise reduction. The headset utilizes a dynamic boom microphone with a hypercardioid polar pattern for tighter pickup and a voice-optimized frequency range of 80 Hz to 16 kHz.

The headband supporting the unit's earcup is rugged, bendable, and twistable, and the boom can be worn on either side of the headset. To preserve your hearing, the headset features a switchable noise-protection mode called ActiveGard that protects against sudden bursts of sound without interrupting the signal or inducing distortion.

The HMD 301 PRO-X4F sports a modular cable design to accommodate multiple pin-outs and configurations. The included XLR 4-pin female cable and each of the separately available compatible cables minimizes handling noise by incorporating a small series of coils that decouple the cable from the headset.  

Advantages of ActiveGard Technology

• The incoming signal is compressed in one controlled operation
• ActiveGard detects an excessive signal and reacts by initiating a compression process that occurs in just a few milliseconds—faster than the human ear
• Due to the compression method, there is virtually no distortion of the signal
• In contrast to peak-clipping circuits, ActiveGard removes the dangerous energy from the signal by means of this compression technique
• The more powerful the incoming signal, the more powerfully the system compresses
• Unlike peak-clipping circuits, ActiveGard keeps the volume at a comfortable level, even if the incoming signal is a sound burst well in excess of the limit which is generally considered to be harmful to hearing

Key Features at a Glance

• Switchable ActiveGard for protected hearing against noise peaks over 110 dB
• Accurate, linear sound reproduction optimized for speech intelligibility
• Dynamic hypercardioid microphone for clear communication, even in noisy environments
• Microphone can be worn on right or left side
• Comfortable padding design allows for extended use in long wearing sessions
• Enhanced ambient noise attenuation in loud environments due to closed passive earcup construction
• Modular cable design allows compatibility with 26-II Series cables
• Foldable earcup design for space-saving storage
• Nameplate can be customized with a company logo or user name