JBL Control 328CT Ceiling Loudspeaker
Consistent 120° broadband pattern control
covers an extremely large area.
Shaped mounting baffle provides the
pattern control of a 300 mm (12 in) horn
from a 200 mm (8 in) driver.
• 200 mm (8 in) woofer with Kevlarreinforced
cone and 50 mm (2 in)
• 25 mm (1" exit) compression driver.
Extraordinary clarity for speech and
vocals with extended frequency response
250 Watt power handling with very high
sensitivity provides high SPL capability.
Advanced high-slope crossover network
for constant coverage and smooth, natural
Clean, contemporary grille and optional
Control 328C and Control 328CT have
been engineered from the ground up to
deliver exceptional next-generation
performance in a coaxial point source
design ceiling loudspeaker. The
combination of the low frequency cone
and the shaped mounting baffle 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 wide, extremely consistent
120° coverage on a broadband basis.
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 handling.
The Control 328C and Control 328CT are
easy to install. The removable multi-pin
locking connector, with secure screw-down
terminals, allows for pre-wiring the input
wires for easy clip-on convenience during
The clean, contemporary look of the
optional MTC-RG6/8 round grille is
designed to suit high-end venues, offering a
simple, elegant appearance that fits into a
wide variety of décors.
The optional MTC-300BB8 one cubic foot
backcan is made of extra-thick 16 gauge
steel and the top is lined with ½” medium
The transformer version Control 328CT
comes with a pre-attached top quality, low
saturation 68 Watt multi-tap transformer for
70V/100V distributed speaker lines.
To ensure long life and reliability, Control
328C/CT passes JBL’s 100-hour torture
power test, the toughest standard in the
System: Frequency Range (-10 dB)1: 45 Hz – 18 kHz
Frequency Response (±3 dB)1: 60 Hz – 16 kHz
Coverage Pattern2: 120° conical, broadband
Directivity Factor (Q): 7.0 (Avg 1k - 16kHz)
Directivity Index (DI): 8.5dB (Avg 1k - 16kHz)
Long-Term System Power Rating, IEC3: 250 W (1000 W peak), 2 hrs
150 W (600 W peak), 100 hrs
Sensitivity (2.83V@ 1m): 93 dB4 measured half-space
98 dB5 computed for competitive comparison
Maximum SPL6: 118 dB cont ave (124 dB peak)
Crossover Network: 1.9 kHz, 3rd order (18 dB/oct) high-pass plus conjugate
to HF, 2nd order low-pass to LF.
Nominal Impedance (328C): 8 ohms
Transformer Taps (328CT): 70V: 68W, 34W, 17W, 8.5W
100V: 68W, 34W, 17W
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
Physical: Input Connector (328C): Removable locking connector with screw-down
terminals. Max wire 12 AWG (2.5 mm2)
328C: 1) + in, 2) + loop out, 3) – loop out, 4) – in
Tap Connection (328CT): 328CT: 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.
Baffle: Metal, round, 305 mm (12.0 in) diamter, driver premounted
to baffle, ported.
Baffle Attachment to MTC-300BB8 Backbox: Attach via 4 #10 x .75 in (19 mm) sheet metal screws.
Grille Attachment to Baffle: 4 pcs 4 mm machine screws.
Dimensions (H x W x D): 305 mm (12.0 in) diameter round baffle x depth from
back of baffle of 160 mm (6.3in) on 328C & 218 mm
(8.6 in) on 328CT.
Net Weight: 328C: 4.5 kg (10.0 lbs) 328CT: 5.4 kg (12.0 lbs)
Shipping Weight: 328C: 5.8 kg (12.7 lbs) 328CT: 6.7 kg (14.7 lbs)
Included Accessories: Ported baffle pre-attached, plus transformer on 328CT.
Optional Accessories: MTC-RG6/8 Grille, round contoured, white.
MTC-300BB8 Backbox, 25 liters (1 cubic feet)
MTC-300T150 Transformer, 150 W for use with 328C.
1 In half space (in ceiling)
2 Average 1 kHz to 10 kHz
3 IEC standard, full bandwidth pink noise with 6 dB crest factor.
4 Measured in half space (in ceiling), ave 100 Hz – 10 kHz.
5 Measured in full space with 6 dB added for half-space calculation. Method used by some European manufacturers, for
6 Calculated based on power rating and measured half-space sensitivity, exclusive of power compression.
JBL continually engages in research related to product improvement. Changes introduced into existing products without
notice are an expression of that philosophy.