Sennheiser HMDC 27 Broadcast Headset with Noise Reduction

Commentary positions at a stadium or a motorsport circuit have an ambient level that closed earcups alone will not solve. The HMDC 27 is the 27-series headset with NoiseGard active noise reduction added, taking a further 15 dB off the low-frequency crowd and engine noise so the commentator can work at a sensible monitoring level instead of a dangerous one.

The part that makes it practical on location is that the ANR needs no batteries: it runs off the P48 the commentary desk already supplies, so there is nothing to charge and nothing to fail mid-event. The boom microphone is dynamic and super-cardioid, 40 to 18,000 Hz at 16 mV/Pa into 300 ohms, and the earcups are closed circumaural at 64 ohms with the ActiveGard limiter. The headset weighs about 240 g without its cable, and the cable itself is interchangeable across the 27 series.