JBL Control 321CT 12" Coaxial 2-WAY Ceiling Spk W Transformer B-Stock
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- SKU
- CONTROL-321CT-B
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.
More Information
| Condition | Refurbished |
|---|
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At a Glance
The JBL Control 321CT is a commercial-grade coaxial ceiling speaker optimized for background music, speech reinforcement, and modest music playback in studio monitoring applications where full-range, balanced tone is needed. Its dual-driver design pairs a 12-inch Kevlar woofer with a titanium compression driver, tuned through a 1.8 kHz crossover for seamless midrange integration and extended frequency response (47 Hz–16 kHz). Built for permanent ceiling installation with integrated transformer and selectable power taps, it simplifies wiring and works as a reference monitor or multi-purpose playback tool in acoustic spaces.
Who This Is For
Great for
- ✓ Commercial installations
- ✓ Speech intelligibility
- ✓ Background music
- ✓ Retail and hospitality
Not the best pick for
- – Live concert sound
- – DJ performance
- – High-fidelity music listening
Skill level: Beginner · Intermediate · Advanced · Professional
Frequently Asked Questions
What does B-Stock mean for this speaker?
B-Stock means the speaker is fully functional and meets all performance specifications, but may have minor cosmetic imperfections from display or handling. All audio performance, power handling, and coverage characteristics are identical to new units.
What amplifier power tap should I use?
The integrated transformer offers four selectable taps (68W, 34W, 17W, 8.5W) to match your amplifier output. Select the tap closest to your amplifier's rated power at 70V or 100V line level—no external step-down transformer required.
Is this speaker suitable for live music or DJ events?
No. The Control 321CT is designed for commercial installations, background music, and speech intelligibility in permanent ceiling applications. It is not intended for live concert sound, DJ performance, or high-fidelity music listening environments.
How much ceiling space does this speaker need?
The speaker mounts into a standard 378 x 378 mm (14.9 x 14.9 inch) ceiling cavity opening. The compact form factor is 14.4 inches H x 14.4 inches W x 9.5 inches D, designed for flush mount installation in drywall or drop ceilings.
What frequency range does it cover?
The speaker delivers ±3 dB response from 47 Hz to 16 kHz, with an extended range (-10 dB) of 34 Hz to 18 kHz. Maximum SPL reaches 118 dB at 1 meter, sufficient for speech clarity and music reinforcement across medium to large spaces.
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