The Sennheiser EW-D EM (R4-9) is a professional digital wireless receiver from the Evolution Wireless Digital series. It is designed to work with: EW-D SK bodypack transmitters EW-D SKM handheld transmitters Lavalier and headset systems Wireless instrument systems for accordion, guitar, bajo quinto, bass, and more. This model operates in the R4-9 frequency range (552–607.8 MHz) and is commonly used in: Touring rigs Live bands Churches Corporate AV Professional stage productions Main Features Digital UHF wireless receiver Frequency range: 552–607.8 MHz Intelligent diversity reception for stable RF performance Ultra-low latency: 1.9 ms Huge dynamic range: 134 dB Bluetooth control with EW-D Smart Assist App Rackmount-compatible half-rack design Up to 90 simultaneous channels Auto frequency scan and synchronization
