The JBL CONTROL 321C is a professional-grade, 12-inch coaxial ceiling loudspeaker engineered for high-output background music and voice reinforcement in demanding commercial and architectural sound installations. This model integrates a high-power 12-inch low-frequency driver with a concentrically mounted 1.5-inch high-frequency compression driver, housed within a single chassis to create a coherent point source with uniform sound dispersion. Its design is specifically tailored for large, reverberant spaces such as airports, sports arenas, large retail environments, and houses of worship, where extended low-frequency response, high sensitivity, and significant acoustic output are required to achieve clear, full-range audio coverage over ambient noise levels.

The coaxial configuration is critical to the speaker's performance, positioning the high-frequency driver at the acoustic center of the woofer's cone to ensure precise phase alignment and a wide, consistent dispersion pattern. This results in smooth off-axis frequency response and eliminates the "lobing" issues common in conventional two-way designs, providing a uniform listening experience across a broad area beneath the speaker. The system includes a built-in multi-tap transformer, making it fully compatible with 70.7V/100V constant-voltage amplifier systems, and also offers a direct 8-ohm mode for low-impedance applications. This allows installers to select the exact power tap to optimize headroom and efficiency for the specific zone.

Installation is facilitated by a rugged, all-steel back-can assembly designed for plenum-rated environments, featuring an adjustable dog-leg mounting system that securely clamps to the ceiling tile or drywall from above. The paintable, low-profile magnetic grille provides a discreet, finished appearance that blends seamlessly into most ceiling designs. With its combination of high power handling, coaxial clarity, and robust construction, the JBL CONTROL 321C serves as a powerful and reliable audio solution for large-scale commercial installations where both sonic performance and installation durability are paramount.