4-Person Noise Cancelling Headset Intercom. The Solidcom C1 Pro, Hollyland's first-of-its-kind full-duplex wireless intercom headset system featuring dual-mic Environmental Noise Cancellation (ENC) technology, is incredibly lightweight and easy to use. It is a true game changer with built-in ENC, ideal for production teams working in loud environments where exceptional communication clarity is essential. This new-generation headset system features a wideband audio range of 150 Hz to 7 kHz, and a reliable LOS communication range of up to 350 m. Its directional main mic focuses precisely on the speaker's voice range, and simultaneously, the omnidirectional secondary mic collects environmental noise from different directions as noise samples. The sound signal is processed with the advanced ENC algorithm, effectively cancelling the environmental noise and delivering crystal-clear sound quality.