Sennheiser XSW 1-835 Dual -- 2-channel analog UHF wireless system for live sound applications. Stable UHF band, built-in antennas and streamlined interface designed with ease of use in mind. Features Sennheiser’s evolution e835 dynamic cardioid capsules. This product page is for the XSW 1-835 Dual-A model, frequency band 548 to 572 MHz.