The Electro-Voice BK-1 is a boundary layer condenser microphone designed for professional installed sound applications where unobtrusive, high-quality audio capture is required. Its low-profile design adheres to the principle of boundary layer technology, where the microphone capsule is positioned flush against a hard surface, such as a conference table, lectern, or wall. This placement effectively eliminates phase cancellations that occur when sound waves reflect off the surface, resulting in a smoother frequency response, increased sensitivity, and improved gain before feedback compared to microphones placed even a small distance away. The microphone is engineered to provide clear, natural sound reproduction ideal for speech reinforcement, teleconferencing, and recording in meeting spaces.

This condenser microphone requires phantom power (typically 48V) supplied by a connected mixer, digital signal processor, or dedicated power supply. It features a cardioid polar pattern that focuses on sound sources directly in front while providing significant rejection of ambient noise and reverberation from the sides and rear. This directionality is crucial for isolating the primary speaker's voice in environments with background chatter or HVAC noise. The BK-1's housing is built for discreet installation, often featuring a low-profile finish that blends with furniture or architectural elements, and it can be surface-mounted using adhesive or mechanical fasteners.

The BK-1 is a solution for modern collaborative spaces, courtrooms, houses of worship, and boardrooms. By combining the acoustic benefits of boundary layer placement with the detailed sonic capture of a condenser element, it addresses common challenges of distant, hollow, or noisy audio in conferencing and presentation environments, delivering reliable and intelligible speech capture for both in-room and remote participants.