The Electro-Voice 100S is a classic, passive two-way constant directivity speaker system designed for high-fidelity sound reinforcement in demanding professional applications. Introduced as a key model within Electro-Voice's industrial line, it quickly gained recognition for its robust construction, high output, and precise acoustic control, making it a staple in both fixed installations and touring sound systems for music and speech. The system combines a high-power 15-inch woofer with a large-format high-frequency compression driver, coupled through a carefully engineered passive crossover network. This component selection and design are focused on delivering exceptional clarity, extended frequency response, and the high sound pressure levels required for large venues and outdoor events.

A defining feature of the 100S is its advanced constant directivity (CD) horn. This horn design maintains a consistent, controlled dispersion pattern over a wide frequency range, ensuring uniform coverage across the listening area and minimizing undesirable off-axis coloration. The predictable coverage simplifies system design, allowing audio engineers to accurately predict how sound will behave in a given space. The speaker's trapezoidal cabinet is constructed from rugged, void-free plywood with extensive internal bracing to minimize resonance and maximize acoustic efficiency. Its durable, textured finish and heavy-duty steel grille are built to withstand the rigors of professional transport and installation, contributing to the speaker's reputation for long-term reliability.

The speaker is engineered for use with high-power external amplifiers, typically in a bi-amped configuration where separate amplifier channels drive the low and high-frequency sections via an external electronic crossover for optimal performance and headroom. However, it also performs superbly in a full-range, passive mode using its internal crossover. With its high sensitivity and substantial power handling, the Electro-Voice 100S can deliver powerful, articulate sound over long distances, making it suitable for applications ranging from concert sound reinforcement and theatrical productions to large houses of worship and permanent stadium installations. Its enduring design and proven performance have solidified its status as a benchmark professional loudspeaker.