The Sennheiser EW-DX SK/SKM-S BASE SET (R1-9) digital handheld transmitter is a dual-channel UHF digital wireless system in the R1‑9 band (520 – 607.8 MHz), consisting of an SKM‑S handheld transmitter, an SK bodypack, an EM 2-channel rack receiver and two BA 70 rechargeable batteries. The system utilises the proprietary SePAC audio codec, which guarantees a wide dynamic range of 134 dB, eliminating the need for manual gain adjustment. System latency is extremely low: just 1.9 ms, perfect for live and broadcast applications.

Thanks to AutoScan technology and equidistant frequency spacing (600 kHz Standard mode – up to 146 channels, 300 kHz Link Density mode – up to 293 channels), the system offers excellent intermodulation resistance and effective automatic configuration. The switching band reaches 88 MHz, expanding flexibility in frequency selection.

The handheld and bodypack transmitters feature metal casings, persistent E‑Ink displays that show parameters even without power, lockable function keys, internal charging contacts and up to 12 hours of battery life with BA 70 batteries. Transmission is protected by AES-256 encryption to ensure content security. The system is “network-ready” and compatible with remote control tools such as Sennheiser Control Cockpit, Wireless Systems Manager and the Smart Assist app (BLE), with a range of up to 25 metres.
Finally, the EM 2 receiver supports PoE (11–13 V or IEEE 802.3af) and network connections via RJ-45, simplifying integration into existing racks.