JBL 328CT, 322CT, 321CT, 322C, 312CS User Manual

User’s Guide

3 0 0 S e r i e s

C o n t r o l 3 2 1C / C T

C o n t r o l 3 2 2 C / C T

C o n t r o l 3 2 8 C / C T

C o n t r o l 3 1 2 C S

TABLE OF CONTENTS

Product Description

Product Feature Identification

Wiring Instructions

Control 328C/CT System

Assembly

Control 321C/CT, Control

322C/CT & Control 312CS

System Assembly

Painting the Grille

Maintenance

Accessories

Contacting JBL Professional

Specifications

3

4

5

7

8

10

10

10

10

11

JBL Professional Control 300 Series

PRODUCT DESCRIPTION

JBL Professional Control® 300 Large Format, In-Ceiling Loudspeakers are designed from the
ground up to provide optimal performance for the most demanding installed sound applications.
Thanks to the conical constant coverage waveguide design, Control 300 Series Loudspeakers
feature exceptional broadband control ensuring extremely even coverage and remarkably
consistent performance. The Control 321C/CT, 322C/CT, 328C/CT and 312CS represent the
state of the art in in-ceiling loudspeaker systems design.

Control 321C - A coaxial design that features a 12” Kevlar­reinforced cone on the woofer coupled with JBL Professional’s
2412 Compression Driver. The Control 321CT offers the same
driver compliment as the Control 321C but also includes a multi­tap transformer for use on 70V or 100V line distribution systems.

Control 322C - A coaxial design that also features a 12” Kevlar­reinforced cone on the woofer coupled with JBL Professional’s
2407H Compression Driver and offers higher power handling
capabilities than Control 321 models. The Control 322CT
offers the same driver compliment as the Control 322C but also
includes a multi-tap transformer for use on 70V or 100V line
distribution systems.

Control 328C - A smaller coaxial design that features a
8” Kevlar-reinforced cone on the woofer coupled with JBL
Professional’s 2412 Compression Driver. The Control 328CT
offers the same driver compliment as the Control 328C and but
includes a multi-tap transformer for use on 70V or 100V line
distribution systems.

Control 312C - An 8 ohm, 12” Kevlar-reinforced cone for
extended bass requirements.

JBL Professional Control 300 Series

3

PRODUCT FEATURE IDENTIFICATION

(Control 322CT Shown)

Transformer

Crossover
Network

Tuning Port
Tube

EZ-Rail™

Crossover
Network

Compression

Driver

Woofer Frame

Baffle

Dust Cap

Tuning
Port Tube

4

JBL Professional Control 300 Series

Woofer

Baffle

Tuning Port

WIRING INSTRUCTIONS

A

D

C

B

E

INPUT CONNECTION FROM

70V/100V AMPLIFIER LINE

Com

30W15W

7.5W

60W

70V

Com

60W

30W15W

N/C

100V

BLACK

ORANGE

PURPLE

BLUE

WHITE

A

D

C

B

E

INPUT CONNECTION FROM

70V/100V AMPLIFIER LINE

Com

50W25W

12.5W

100W

70V

Com

100W

50W25W

N/C

100V

BLACK

ORANGE

PURPLE

BLUE

WHITE

+

-

1 432

Loop
Thru

IN

IN

+

-

Loop
Thru

CONNECTION

+

IN

1 2

-

Loop
Thru

+

-

+

3 4

-

IN

Loop
Thru

+

-

Control 300 Series Loudspeakers include Euroblock or
Phoenix-type locking input connectors that allow the system
to be “pre-wired” before the speakers are installed into their
respective back cans and backboxes.

Connecting the Wiring to the Euroblock -- Connect the
wiring to the removable locking connector that is INCLUDED
with the speaker by stripping the insulation back about 5
mm (about 3/16 inch), inserting the bare end of wire into
the connector and screwing down the hold-down screw until
tight using a small flatblade screwdriver. Tighten any unused
screws to avoid vibration. Using terminal block connectors
allows the system to be pre-wired before final installation of
the drivers.

When wiring Control 300 Series loudspeakers,
always use proper electrical wiring practices
in accordance with your area’s building codes
and regulations.

Guide to Connection Pins on Transformer Models
(Control 328CT, 321CT & 322CT) -- The removable locking

input connector contains 5 terminals, as marked on the
connector. The pin functions are listed on the label located
on the crossover frame.

Control 321CT & 328CT:

Guide to Connection Pins on Low Impedance Models
(Control 321C, 322C, 328C & 312CS) -- The removable

locking input connector contains 4 terminals, as marked on
the connector. The pin functions for the Control 328C, 328C
and 322C are listed on the label located on the crossover
frame and on the driver backplate on the Control 312CS.

Control 328C, 321C,

322C & 312CS:

Pins 1 & 4 are the “+” and “-” inputs to the loudspeaker.
Connect the negative wire to the “-” or pin 4 and connect the
positive wire to “+” or pin 1. Pins 1 & 4 are looped to pins 2 &
3, respectively (Pin 1 connects to Pin 2 and Pin 3 connects
to Pin 4) inside the speaker. Pins 2 & 3 are intended as loop­through connections to subsequent loudspeakers. There are
two possible hookup schemes for connecting subsequent
speakers, determined by the desired result from the circuit
whenever this speaker’s connector gets disconnected during
troubleshooting.

Hookup Schemes for Subsequent Speakers

Choose whichever of the following hookup patterns best
accommodates your installation.

Control 322CT:

For Control 328CT, 321CT and Control 322CT (transformer
models), connect the negative input to the “Common” terminal
and connect the positive input to the appropriate tap. For

example, if the system is being driven from a 70V Distributed
Line and in the case of the Control 321CT the 30W tap is
desired, the positive input would be made to the input marked
30W and the negative connection would be made to the
“Common” pin. The input pins correspond to the taps of the

transformer indicated on the label below each connector.

1.) Paralleling Input Terminals -- Connect the wire pair of
the subsequent speaker to pins 1 & 4 (in parallel with the
input wire pair). Whenever the connector is pulled out of the
speaker for troubleshooting, subsequent speakers will stay
connected. This can be useful during troubleshooting to be
able to disconnect a single loudspeaker at a time. In this
hookup scheme, no wires get connected to pins 2 & 3.

Figure A:
Paralleling Input Terminals

From Amplifier or

Previous Speaker

JBL Professional Control 300 Series

To Subsequent

Speakers

5

WIRING INSTRUCTIONS

Power Amp

+

-

1

234

Speaker 1

1

234

Speaker 3

1

234

Speaker 2

+

-

+

IN

1 2

-

Loop
Thru

+

-

+

3 4

-

IN

Loop
Thru

+

-

Power Amp

+

-

1

234

Speaker 1

1

234

Speaker 3

1

234

Speaker 2

+

-

Figure B:
Parallel System
Hookup Diagram

2.) Using Loop-Through Terminals (Pins 2 & 3) -- By
connecting the wire pair of the subsequent speaker to pins
2 & 3, then all subsequent speakers will be disconnected
when this speaker’s connector is disconnected during
troubleshooting . This can be useful as a way to isolate
problems to a section of the distributed line while leaving the
wires attached to the connector.

Figure C:
Using Loop­Through Terminals

From Amplifier or

Previous Speaker

Figure D:
Loop-Through System
Hookup Diagram

Control 227C

To Subsequent

Speakers

JBL Professional Control 300 Series

6

CONTROL 328C/CT SYSTEM ASSEMBLY

Ceiling Preparation - Cut a 12.2 inch (310 mm)

diameter hole in the ceiling to allow sufficient room for the
loudspeaker baffle.

Assembling the Control 328C/CT into the Back Can

- After inserting the Control 328C/CT into the back can,
align the mouting holes without weld nuts to the holes with
clip nuts on the back can. These are the mounting points
that will be used to secure the Control 328 baffle and driver
to the backcan.

Non-Weld nut
mount point

Weld nut
mount point

Next, using 4 pcs - #10 x 0.75 in (19 mm) sheet metal
screw, attaching the baffle / driver to the back can. Be
sure to match the mouting holes without weld nuts to clip
nuts on back can.

Finally, using 4 pcs - M4 x 38 mm powder coated machine
screws, attach the metal grille to the baffle. Be sure to
match the grille mouting holes to the weld nuts on the
baffle assembly.

IMPORTANT!

When installing the
MTC-300BB8 with a
Control 328C/CT,
see “Securing Speaker
Assembly to the Building
Structure” details below.

4 pcs - #10 x 0.75 in (19 mm)

sheet metal screw for attaching

the baffle / driver to the back

can. Match to clip nuts on

back can. (Included with MTC-

300BB8. )

4 pcs - M4 x 38 mm powder
coated machine screws for
attaching the metal grille to
the baffle. (Included with JBL
Professional grilles.)

IMPORTANT: SECURING SPEAKER ASSEMBLY TO THE BUILDING STRUCTURE

The backcan must be secured to the building structure by qualified personnel in accordance with safe
installation practices. Use suspension materials, connection fixturing, and methods that are appropriate for
the building structure and installation conditions. Employ a minimum 5:1 safety factor for each suspension
point, or higher if required by code. For MTC-300BB8 with a Control 328C/CT a 5:1 safety factor requires
that each suspension point be rated to support a minimum of 57 kg (125 lbs).

JBL Professional Control 300 Series

7

CONTROL 321C/CT, 322C/CT & 312CS SYSTEM ASSEMBLY

MTC-300BB12 Back Box
Shown as Cut-Away for Clarity

Loudspeaker

Assembling the Control 321C/CT, 322C/CT or 312CS
into the Back Box - First, line up the EZ-Rail™ with one

of the back box flanges containing a singular mounting hole.
For orientation when holding the speaker overhead, two
(2) embossed arrows on the underside of the metal baffle
indicate the edge with the EZ-Rail.

Next, slide the EZ-Rail onto the flange of the JBL MTC­300BB12 (or compatible) back box. The EZ-Rail helps to
hold one side of the speaker baffle TEMPORARILY while
the installer installs the screws that hold the baffle.

IMPORTANT: THE INSTALLER MUST SECURE THE
BAFFLE IN PLACE WITH SCREWS ON ALL SIDES.

Pre-Mounted
Metal Baffle

1

2

JBL Professional Control 300 Series

8

CONTROL 321C/CT, 322C/CT & 312CS SYSTEM ASSEMBLY

Ceiling Preparation - Cut a 14.9 x 14.9 inch

(378 x 378 mm) hole in the ceiling to allow
sufficient room for the loudspeaker baffle.

Using JBL Professional’s MTC-300BB12
Back Box -- The MTC-300BB12 is

compatible with two common mounting
systems for installing the loudspeaker
/ baffle to the back box; either of these
mounting systems may be utilized. Screws
are included with the MTC-300BB12 Back
Box.

Using 4 pcs - M4 x 38mm powder coated
machine screws, attach the metal grille
to the baffle. Be sure to match the grille
mouting holes to the weld nuts on the baffle
assembly.

6 pcs - #10 x .75 in (19mm) sheet
metal screw for attaching the
driver / baffle to the back box.
Match to clip nuts on back box.

2 Points Each Sid e

IMPORTANT!

When installing the
MTC-300BB12 with
a Control 321C/CT,
322C/CT & 312CS
models see “Securing
Speaker Assembly to
the Building Structure”
details below.

1 Point E ach End

4 pcs - M4 x 38mm powder
coated machine screws for
attaching the metal grille to
the baffle. (Included with JBL
Profesional grilles.)

Using a different brand compatible back box

-- Screwholes in the metal baffle are provided
corresponding with two common mounting systems.
Utilize the system that works with that particular
back box.

4 pcs - M4 x 14mm sheet metal
screw for attaching the driver /
baffle to the back box. Match to
corners on back box.

1 Point Ea ch Cor ner

IMPORTANT: SECURING SPEAKER ASSEMBLY TO THE BUILDING STRUCTURE

The backcan must be secured to the building structure by qualified personnel in accordance with safe
installation practices. Use suspension materials, connection fixturing, and methods that are appropriate for
the building structure and installation conditions. Employ a minimum 5:1 safety factor for each suspension
point, or higher if required by code. For MTC-300BB12 with a Control 321C/CT, 322C/CT or 312CS, a 5:1
safety factor requires that each suspension point be rated to support a minimum of 156 kg (345 lbs).

JBL Professional Control 300 Series

9

ACCESSORIES, MAINTENANCE & CONTACTING JBL

Painting the Grille -- Control 300 Series Grilles feature

a powder coated, satin finish paint (RAL 9016 - Pantone
equivalent 11-0602TPX) and can be painted to match any
decor. This should only be done when the grilles have
been removed from their loudspeaker and back box / can
assembly.

For best results, a spray paint technique is recommended.
If the grille is rolled or brush painted, the grille perforations
may become clogged with paint and poor sound quality may
result.

Maintenance -- No maintenance is required when assembled
in accordance with the instructions and wiring guidelines
described in this manual.

Optional Accessories

MTC-RG6/8 Grille - a round, contoured grille for use with the
Control 328C/CT Loudspeaker System.

MTC-300BB8 Backbox - a round, one cubic foot (nominal, back­box for use with the Control 328C/CT Loudspeaker System.

MTC-300SG12 Grille - a square, contoured grille for use with
the Control 321C/CT, 322C/CT & 312CS Loudspeaker Systems.

MTC-300BB12 Backbox - a round, three cubic foot (nominal), for
use with the Control 321C/CT, 322C/CT & 312CS Loudspeaker
Systems.

MTC-300T150 Transformer - a 100V, 150W (plus 75W at 70V)
transformer for applications requiring high power.

Contacting JBL Professional -- These products are
designed and backed by JBL Professional, the world
leader in professional sound reinforcement. For complete
warranty information, to order replacement parts or to ask for
clarifications to this manual, contact JBL Professional.

Within the United States:

Applications Department, JBL Professional
8400 Balboa Blvd., PO Box 2200
Northridge, CA 91329 USA

In the USA you may call Monday through Friday 8:00am to
5:00pm Pacific Coast Time [phone].

Outside the USA:

Contact the JBL Professional Distributor in your country.

A list of JBL Professional Distributors and US Service
Centers can be obtained from the JBL Professional website
at: www.jblpro.com

JBL Professional Control 300 Series

10

SPECIFICATIONS

LISTED

General Signaling
Equipment

15CM

Control 328C/CT

Frequency Range (-10 dB)1: 45 Hz – 18 kHz
Frequency Response (±3 dB)
Coverage Pattern
Long-Term System Power Rating, IEC3: 250 W (1600 W peak), 2 hrs

150 W (1000 W peak), 100 hrs
Sensitivity (2.83V@ 1m): 93 dB

Nominal Impedance : 8 ohms (328C)
Transformer Taps : 100V: 68W, 34W & 17W (plus 8.5W at 70V)
Transducers : 8” woofer with Kevlar reinforced cone, 1” exit magnet compression driver
Input Connector : Removable locking connector with screw-down terminals.

Safety Agency Rating : Suitable for use in air handling spaces, per U.L.-2043, U.L.-1480, NFPA90 & NFPA70A.

Net Weight : 328C:
Dimensions (Diameter x D) : 328C: Ø
328CT: Ø

Control 321C/CT

Frequency Range (-10 dB)1: 34 Hz – 18 kHz
Frequency Response (±3 dB)
Coverage Pattern2: 90º conical, broadband (Avg 1k - 16kHz)
Long-Term System Power Rating, IEC

200 W (1000 W peak), 100 hrs
Sensitivity (2.83V@ 1m): 94 dB

Nominal Impedance : 8 ohms (321C)
Transformer Taps : 100V: 68W, 34W & 17W (plus 8.5W at 70V)
Transducers : 12” woofer with Kevlar reinforced cone, 1” exit magnet compression driver
Input Connector : Removable locking connector with screw-down terminals.

Safety Agency Rating : Suitable for use in air handling spaces, per U.L.-2043, U.L.-1480, NFPA90 & NFPA70A.

Net Weight : 321C:
Dimensions (H x W x D) : 321C: 366 x 366 x
321CT: 366 x 366 x

1

: 60 Hz – 16 kHz

2

: 120º conical, broadband (Avg 1k - 16kHz)

4

measured half-space

4.5 kg (10.0 lbs) 328CT: 5.4 kg (12.0 lbs)
305 mm

(12 in) x 160 mm (6.3 in)

305 mm

(12 in) x 218 mm (8.6 in)

1

: 47 Hz – 16 kHz

3

: 250 W (1600 W peak), 2 hrs

4

measured half-space

7.3 kg (16.0 lbs) 321CT: 8.2 kg (18.0 lbs)

223 mm

(14.4 x 14.4 x 8.8 in) depth from back of baffle

240 mm (

14.4 x 14.4 x

9.5 in)

depth from back of baffle

Control 322C/CT

Frequency Range (-10 dB)1: 32 Hz – 20 kHz
Frequency Response (±3 dB)1: 48 Hz – 19 kHz
Coverage Pattern2: 90º conical, broadband (Avg 1k - 16kHz)
Long-Term System Power Rating, IEC3: 400 W (1600 W peak), 2 hrs

250 W (1000 W peak), 100 hrs
Sensitivity (2.83V@ 1m): 95 dB

4

measured half-space
Nominal Impedance : 8 ohms (322C)
Transformer Taps : 100V: 100W, 50W & 25W (plus 12.5W at 70V)
Transducers : 12” woofer with Kevlar reinforced cone, 1” exit neodymium-magnet compression driver
Input Connector : Removable locking connector with screw-down terminals.

Safety Agency Rating : Suitable for use in air handling spaces, per U.L.-2043, U.L.-1480, NFPA90 & NFPA70A.

Net Weight : 322C: 9.1 kg (20.0 lbs) 322CT: 10.0 kg (22.0 lbs)
Dimensions (H x W x D) : 322C: 366 x 366 x
322CT: 366 x 366 x

223 mm

(14.4 x 14.4 x 8.8 in) depth from back of baffle

240 mm (

14.4 x 14.4 x

9.5 in)

depth from back of baffle

Control 312CS

Frequency Range (-10 dB)1: 30 Hz – 4.5 kHz
Frequency Response (±3 dB)1: 34 Hz – 3.5 kHz
Long-Term System Power Rating, IEC5: 400 W (1600 W peak), 2 hrs

250 W (1000 W peak), 100 hrs
Sensitivity (2.83V@ 1m): 93 dB

4

measured half-space
Nominal Impedance : 8 ohms
Transducers : 12” woofer with Kevlar reinforced cone
Input Connector : Removable locking connector with screw-down terminals.

Safety Agency Rating : Suitable for use in air handling spaces, per U.L.-2043, U.L.-1480, NFPA90 & NFPA70A.

Net Weight : 312CS: 7.7 kg (17.0 lbs)
Dimensions (H x W x D) : 312CS: 366 x 366 x

160 mm

(14.4 x 14.4 x 6.3 in) depth from back of baffle

1

In half space (in ceiling)

2

Average 1 kHz to 16 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

AES pink noise, 30 Hz to 300 Hz with 6 dB crest factor.

JBL continually engages in research related to product improvement. Changes introduced into existing products without notice are an expression of that philosophy.

JBL Professional Control 300 Series

11

363816-001

3 0 0 S e r i e s

8500 Balboa Boulevard

Northridge, CA 91329 USA

Visit us online at www.jblpro.com