The Sennheiser EM XSW 1 B Fixed Radio Microphone Receiver with NT 12 5CW Power Supply is a fixed radio microphone receiver belonging to the XS Wireless 1 series and powered by the NT 12-5 CW adapter. Designed for live applications such as stages, theatres and presentations, it integrates internal antennas with antenna switching diversity technology, ensuring stable transmissions and reducing the risk of signal dropouts. The receiver uses the double superheterodyne principle, operating over a wide range of UHF frequencies (e.g. band B: 614–638 MHz) with up to 8 banks and 10 preset channels each, for a total of 80 channels. It offers a sensitivity of less than 3 µV at 52 dB(A) rms S/N and an AF frequency response of 50 Hz–16 kHz (–3 dB).
The audio output includes an unbalanced 1/4″ connector (+6 dBu) and a balanced XLR (+12 dBu).

You can adjust the audio over a range of 45 dB (in 5 dB steps), activate squelch from 3 to 28 dBµV (combined with pilot tone) and switch between line and microphone level (+20 dB).
The system supports automatic synchronisation via a 2.4 GHz remote channel (low-power OQPSK), simplifying the pairing of transmitter and receiver. Built with a robust AB S housing, the receiver weighs approximately 340 g and measures 200 × 42 × 127 mm. In addition to the receiver and NT 12-5 CW power supply, the system also includes an SKM 825-XSW-B handheld transmitter, an MZQ 1 microphone clip and two AA batteries.