Product Description

JBL Control 321CT 12" Coaxial 2-Way Ceiling Speaker with Transformer

The Control 321CT is a professional-grade coaxial ceiling speaker engineered for commercial installations where consistent coverage and clarity matter. Its compact 14.4" footprint mounts flush into standard ceiling cavities, delivering controlled dispersion across large spaces without drawing attention. Built for permanent installation in offices, retail, hospitality, and institutional environments, this speaker combines robust construction with straightforward 70V/100V amplifier compatibility.

Audio Performance & Coverage

The dual-driver coaxial design pairs a 12" Kevlar-reinforced woofer with a titanium-diaphragm compression driver, tuned through a 1.8 kHz 3rd order crossover for seamless midrange integration. Frequency response extends from 47 Hz to 16 kHz (±3 dB), with maximum SPL reaching 118 dB at 1 meter—sufficient for intelligible speech and music reinforcement across medium to large spaces. The 90° conical constant-directivity pattern ensures uniform tonal balance throughout the coverage area, eliminating hot spots and dead zones common in poorly-designed ceiling installations.

Installation & Power Handling

The integrated 70V/100V step-down transformer offers four selectable taps (68W, 34W, 17W, 8.5W), allowing level matching without external components—simply wire to the amplifier line and set the tap for your load. With 250W continuous power capacity and 1000W peak handling, the speaker accommodates both modest background systems and higher-output installations. The metal baffle and ported enclosure design provide extended low-end response while the pre-mounted driver assembly simplifies ceiling cutout installation into the standard 378 x 378 mm (14.9 x 14.9 in) opening.

Key Features

• 12" Kevlar-reinforced low-frequency driver
• Titanium-diaphragm compression driver for high frequencies
• Frequency response ±3 dB: 47 Hz – 16 kHz
• Extended range (-10 dB): 34 Hz – 18 kHz
• Maximum SPL: 118 dB at 1 meter
• Power capacity: 250W long-term / 1000W peak
• 1.8 kHz 3rd order crossover with conjugate networks
• 90° conical constant-directivity coverage pattern
• Integrated 70V/100V transformer with four selectable taps (68W, 34W, 17W, 8.5W)
• Compact ceiling-mount form factor: 14.4" H x 14.4" W x 9.5" D
• Metal baffle with ported enclosure design
• Sensitivity: 94 dB (1 kHz - 16 kHz)

The Control 321CT delivers the reliability and acoustic precision expected in professional installations, backed by JBL's proven engineering for commercial audio systems.