Sennheiser HMD 27 Audio headset, 64 Ω per system, circumaural, dynamic microphone, hypercardioid, cable not included

Product Overview

The Sennheiser HMD 27 is a professional broadcast circumaural headset designed for commentators and engineers who work in demanding, high-noise field environments where durability and off-axis rejection are paramount. It is built on the same proven ergonomic platform as the HME 27, but fitted with a dynamic hypercardioid microphone — a capsule technology that offers superior resistance to RF interference, extreme ambient noise, and the physical rigors of field production. The closed circumaural ear cups deliver high passive attenuation, keeping monitoring clean even in open-air stadiums and racing venues. As with all HM 27-series headsets, a compatible CABLE II series cable is sold separately.

Product Description

The HMD 27 carries forward the ergonomic innovations of Sennheiser's HM 26 platform into a rugged broadcast package purpose-built for field use. The split two-piece headband opens automatically and rests against the sides of the head rather than the fontanelle, preventing the discomfort and fatigue common with traditional arch designs during long commentary sessions. A wide single-piece headband pad is included for users who prefer conventional fit. The soft circumaural ear cushions wrap around the ear to form a reliable acoustic seal that suppresses crowd roar, engine noise, and other extreme ambient levels. The dynamic hypercardioid microphone captures voice with a tight forward pickup pattern and strong off-axis rejection — reducing bleed from adjacent commentators and environmental noise — while its inherent robustness makes it less susceptible to humidity, physical shock, and RF interference than condenser alternatives. This makes the HMD 27 a preferred choice for outdoor sports events, motorsport venues, and any field application where reliability under pressure matters as much as audio quality. The swiveling ear cup allows single-sided listening for talkback monitoring without removing the headset, and the boom arm repositions from right to left side to suit the user. ActiveGard hearing protection with an on/off switch guards against sudden noise peaks above 110 dB SPL. The 64 Ω system impedance ensures broad compatibility with professional broadcast amplifiers and intercom panels.

Key Features

• Dynamic Hypercardioid Microphone — Tight polar pattern and strong off-axis rejection minimize bleed from adjacent sources in loud environments.
• RF Interference Resistance — Dynamic capsule is inherently immune to RF interference common on dense broadcast production floors.
• Split Two-Piece Headband — Distributes weight away from the fontanelle for fatigue-free extended use.
• Circumaural Closed-Back Design — High passive attenuation for clean monitoring in extreme noise environments.
• 64 Ω System Impedance — Broad compatibility with professional broadcast amplifiers and intercom systems.
• ActiveGard Hearing Protection — Switchable peak limiting above 110 dB SPL protects hearing during sudden loud events.
• Swiveling Ear Cup — Single-sided listening mode without removing the headset.
• Left/Right Repositionable Mic Boom — User-adjustable side positioning without tools.
• Modular Cable System — CABLE II series compatible (cable sold separately) for facility standardization.
• Replaceable Ear Cushions — Supports hygiene maintenance in shared multi-user deployments.
• Included Headband Pad — Converts split headband to single-piece configuration.

Typical Applications

• Outdoor sports broadcasting (football, rugby, motorsport, cycling)
• Field production and outside broadcast (OB) vans
• Stadium and arena commentary positions
• Live event production talkback in high-noise environments
• Television and radio remote production
• Any broadcast application where RF interference or extreme ambient noise is a concern

Technical Specifications

Frequently Asked Questions

Q: Is a cable included with the HMD 27?

No. The HMD 27 ships without a cable. Sennheiser CABLE II series cables are compatible and available separately — contact Creation Networks for guidance on the correct cable for your system.

Q: What is the difference between the HMD 27 and the HME 27?

Both headsets share the same ergonomic platform. The HMD 27 uses a dynamic hypercardioid microphone, offering greater durability, RF interference immunity, and tighter off-axis rejection. The HME 27 uses a condenser cardioid microphone, providing higher sensitivity and a more detailed sound character suited to controlled studio environments.

Q: Why choose a dynamic microphone for broadcast?

Dynamic microphones are more physically robust, immune to RF interference, and less sensitive to humidity than condensers. For field production, outdoor venues, and high-noise environments, these characteristics translate directly into more reliable, consistent performance.

Q: What does hypercardioid mean and why does it matter?

Hypercardioid is a tighter polar pattern than standard cardioid. It rejects sound arriving from the sides more aggressively, which reduces bleed from adjacent commentators and crowd noise reaching the microphone capsule — critical in dense commentary booth setups.

Q: What does ActiveGard do?

ActiveGard is Sennheiser's switchable hearing protection circuit that limits sudden audio peaks above 110 dB SPL at the ear. It protects operators from unexpected loud signals such as crowd surges or technical line faults during live broadcasts.

Q: Can the microphone boom be repositioned?

Yes. The boom arm can be moved to either the left or right side without tools, accommodating individual operator preference or facility convention.

Q: Is the HMD 27 compatible with standard broadcast intercom systems?

Yes. The 64 Ω system impedance is compatible with a wide range of professional broadcast amplifiers and intercom mainframes. Check your specific system's impedance requirements before ordering.

Q: Where can I order compatible cables and accessories?

Creation Networks stocks Sennheiser accessories including compatible CABLE II series cables. Visit creationnetworks.net or contact our team for tailored recommendations.