The Sennheiser EW-D CI1 SET (R4-9) is a professional, fully digital wireless system specifically engineered for electric guitarists and bassists, providing cable-free mobility with pristine audio fidelity across a wide UHF frequency range (R4-9, typically 470-694 MHz region-specific). This system delivers robust, interference-resistant RF performance suitable for the most demanding live stages and studio sessions. The set includes a specialized digital bodypack transmitter with a built-in high-quality direct input (DI) circuit and a compatible true-diversity receiver, offering a complete, optimized solution that captures the pure tone of the instrument at the source and transmits it digitally without compromising the instrument's natural character, dynamic response, or high-gain integrity.

The core of the system is the CI 1 instrument bodypack transmitter. It features a standard 1/4-inch input jack for connecting the instrument cable and incorporates a sophisticated, high-impedance DI circuit designed to faithfully capture the full frequency range, nuanced harmonics, and playing dynamics of magnetic pickups and active electronics. This ensures the tonal signature—from sparkling cleans to saturated distortion—is transmitted with accuracy. The digital signal conversion occurs within the transmitter itself, creating a clean, secure digital stream for wireless transmission that is immune to the intermodulation distortion common in analog UHF systems. The compact digital receiver features a clear color display for monitoring system status, RF signal strength, audio levels, and transmitter battery life, along with advanced features like automatic frequency management and 128-bit AES encryption.

Engineered for seamless integration into a professional musician's signal chain, the system offers plug-and-play simplicity with intelligent channel selection that scans the wide UHF band to find the optimal frequency. The digital architecture provides ultra-low latency that feels instantaneous to the player, a wide dynamic range that preserves picking attack and sustain, and consistent performance up to its full operating range. The receiver provides both balanced XLR and unbalanced 6.3 mm jack outputs, allowing direct connection to a guitar amplifier input, pedalboard, or mixing console. As a complete set, the Sennheiser EW-D CI1 (R4-9) provides guitarists and bassists with a reliable, high-fidelity digital wireless solution that combines the freedom of wireless performance with the uncompromised tone and responsive feel demanded by professional musicians on global tours and in fixed installations.