The Sennheiser HMD 300 PRO is a closed-back, circumaural communications headset with a sonic design based on the HD 250 linear headphones, giving you a detailed, linear response. The headset features a 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 offers a dynamic boom microphone, one that delivers a hypercardioid polar pattern for focusing on vocals, and a frequency range centered around picking up the human voice in communication settings (80 Hz to 16 kHz).

The headband supporting the unit's earcups 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.

The HMD 300 Pro sports a modular cable design to accommodate multiple pin-outs and configurations. Though no cable is included with the headset, each of the compatible cables sport a design that minimizes handling noise; this is achieved with a small series of coils on the cable approach that decouple the cable from the headset. 

ActiveGard Technology

• This sound compression system consists of an electrical circuit incorporated into analogue headsets.
• Compression technology removes the energy from an excessive incoming signal transmitted through the communication system, leaving the signal free of distortion.
• The ActiveGard circuit can be compared to an automatic and fast-working “intelligent” volume control. If an incoming signal rises to a level that is harmful to your hearing, it is instantly “turned down” to a lower, more comfortable level.
• When the incoming signal returns to safe levels, ActiveGard reverts to its stand-by surveillance mode and volume is restored to its original level.

Key Features at a Glance

• Switchable ActiveGard mode for hearing protection 
• Linear sound reproduction optimized for speech intelligibility
• Microphone can be worn either on right or left side
• Comfortable padding design allows for extended use in long wearing sessions
• Passive ambient noise attenuation due to closed earcup construction
• Foldable earcup design