JBL Control 321C Premium 12” Coax Ceiling Loudspeaker
Consistent 90° broadband pattern control.
• 300 mm (12 in) woofer with Kevlar-reinforced
cone with 50 mm (2 in) voice-coil.
• 25 mm (1 exit) compression driver.
Extraordinary clarity for speech and vocals
with extended frequency response for
250 Watt power handling with high
sensitivity provides high SPL capability.
Advanced high-slope crossover network
for constant coverage and smooth, natural
Clean, contemporary grille and optional
Control 321C and Control 321CT have
been engineered from the ground up to
deliver exceptional next-generation performance
in a coaxial point source design
ceiling loudspeaker. The low frequency
cone performs as a true 12 inch (300 mm)
diameter waveguide for the high frequencies.
A unique metal throat transitions
seemlessly to the horn to eliminate high
frequency beaming which is common
among this category of speaker. The
result is a coaxial speaker with extremely
consistent 90ş coverage on a broadband
Component features include a Kevlarreinforced
low frequency cone for reliability,
well-damped surround for smooth
frequency response, high temperature
voicecoil and a reduced distortion design
through saturated-gap magnet geometry.
The high frequency driver features a pure
titanium diaphragm for high sensitivity and
long life, with diamond surround for resonance
control and FerroFluid™ for increased power
The Control 321C and Control 321CT are
easy to install. The innovative EZRail™ feature
built into the metal baffl e temporarily holds
one side of the speaker baffl e in place until
the installer can affi x the baffl e to the backcan
with screws. The removable multi-pin locking
connector, with secure screw-down terminals,
allows for pre-wiring the input wires for easy
clip-on convenience during installation.
The clean, contemporary look of the optional
MTC-300SG12 square grille is designed
to suit high-end venues, offering a simple,
elegant appearance that fi ts into a wide variety
The optional, best-in-class, MTC-300BB12
three cubic foot backcan is made of extra-thick
16 gauge steel and lined with ˝” medium
density fi berboard to provide the performance
of a top quality wood loudspeaker cabinet in a
metal backbox form factor.
The transformer version Control 321CT
comes with a pre-attached top quality, low
saturation 68 Watt multi-tap transformer for use
on 70V or 100V distributed speaker lines.
To ensure long life and reliability, Control
321C/CT passes JBL’s 100-hour torture power
test. Nobody in the industry has more demanding
System: Frequency Range (-10 dB)1: 34 Hz – 18 kHz
Frequency Response (±3 dB)1: 47 Hz – 16 kHz
Coverage Pattern2: 90° conical, broadband (Avg 1k - 16kHz)
Directivity Factor (Q): 8.7 (1k - 16kHz)
Directivity Index (DI): 9.4 dB (1k - 16kHz)
Long-Term System 250 W (1000 W peak), 2 hrs
Power Rating, IEC3: 200 W (600 W peak), 100 hrs
Sensitivity (2.83V@ 1m): 94 dB4 measured half-space
99 dB5 computed for competitive comparison
Maximum SPL6: 118 dB cont ave (124 dB peak)
Crossover Network: 1.8 kHz, 3rd order (18 dB/oct) high-pass plus conjugate to
HF, 2nd order low-pass to LF.
Nominal Impedance (321C): 8 ohms
Transformer Taps (321CT): 70V: 68W, 34W, 17W, 8.5W 100V: 68W, 34W, 17W
Transformer Insertion Loss (CT): 0.9 dB typ.
Transducers: Low Frequency Driver: Kevlar reinforced cone, 50 mm (2 in) voice coil.
High Frequency Driver: JBL 2412H-1 compression driver, 25 mm (1 in) voice coil.
Physical: Input Connector (321C): Removable locking connector with screw-down terminals.
Max wire 12 AWG (2.5 mm2)
321C: 1) + in 2) + loop out
3) – loop out 4) – in
Tap Connection (321CT): 321CT: A) Common
B) 8.5W@70V, 17W@100V
C) 17W@70V, 34W@100V
D) 34W@70V, 68W@100V
E) 68W@70V, n/c@100V
Safety Agency Rating: Suitable for use in air handling spaces, per U.L.-2043, U.L.
1480, NFPA90 & NFPA70A. In accordance with IEC60849 /
EN60849, Transformer in CT model UL Listed per UL1876.
Baffl e: Metal, 366 x 366 mm (14.4 x 14.4 in), driver pre-mounted
to baffl e, ported, EZRail™ for easier installation to backbox.
Baffl e Attachment to Attach via either 4 corner holes M4 x 14 mm machine
MTC-300BB12 Backbox: screws, or 6 side/end holes #10 x .75 in (19 mm) sheet
Grille Attachment to Baffl e: 4 pcs 4 mm machine screws in corners.
Dimensions (H x W x D): 366 x 366 mm (14.4 x 14.4 in) square baffl e x depth from
back of baffl e of 223 mm (8.8 in) on 321C & 240 mm
(9.5 in) on 321CT.
Net Weight: 321C: 7.3 kg (16.0 lbs) 321CT: 8.2 kg (18.0 lbs)
Shipping Weight: 321C: 8.8 lbs (19.4 lbs) 321CT: 9.8 kg (21.6 lbs)
Included Accessories: Ported baffl e pre-attached, transformer on 321CT.
Optional Accessories: MTC-300SG12 Grille, square contoured, white.
MTC-300BB12 Backbox, 80 liters (3 cubic feet)
MTC-300T150 Transformer, 150 W for use with 321C.