d&b J-INFRA User Manual

J-INFRA
Manual (1.1 EN)

Symbols on the equipment

Please refer to the information in the operating manual.

WARNING!
Dangerous voltage!

Contents

Safety precautions...............................................................3

Information regarding use of loudspeakers...............................................3

J-INFRA.................................................................................4

Connections.........................................................................................................4

Operation............................................................................................................5

Technical specifications.....................................................................................6

Manufacturer's Declarations...............................................7

EU conformity of loudspeakers (CE symbol)..............................................7

WEEE Declaration (Disposal)..........................................................................7

General Information

J-INFRA Manual

Version 1.1 EN, 01/2014, D2984.EN .01

Copyright © 2014 by d&b audiotechnik GmbH; all rights reserved.

Keep this manual with the product or in a safe place so that it is
available for future reference.

When reselling this product, hand over this manual to the new
customer.

If you supply d&b products, please draw the attention of your customers
to this manual. Enclose the relevant manuals with the systems. If you
require additional manuals for this purpose, you can order them from
d&b.

d&b audiotechnik GmbH
Eugen-Adolff-Strasse 134, D-71522 Backnang, Germany
Telephone [phone], Fax [phone]
E-mail: [e-mail], Internet: www.dbaudio.com

Safety precautions

Information regarding use of loudspeakers

WARNING!

CAUTION!

Never stand in the immediate vicinity of loudspeakers driven at a high
level. Professional loudspeaker systems are capable of causing a sound
pressure level detrimental to human health. Seemingly non-critical
sound levels (from approx. 95 dB SPL) can cause hearing damage if
people are exposed to it over a long period.

In order to prevent accidents when deploying loudspeakers on the
ground or when flown, please take note of the following:

When setting up the loudspeakers or loudspeaker stands, make sure
they are standing on a firm surface. If you place several systems on top
of one another, use straps to secure them against movement.

Only use accessories which have been tested and approved by d&b for
assembly and mobile deployment. Pay attention to the correct
application and maximum load capacity of the accessories as detailed in
our specific “Mounting instructions” or in our "Flying system and Rigging
manuals".

Ensure that all additional hardware, fixings and fasteners used for
installation or mobile deployment are of an appropriate size and load
safety factor. Pay attention to the manufacturers' instructions and to the
relevant safety guidelines.

Regularly check the loudspeaker housings and accessories for visible
signs of wear and tear, and replace them when necessary.

Regularly check all load bearing bolts in the mounting devices.

Loudspeakers produce a static magnetic field even if they are not
connected or are not in use. Therefore make sure when erecting and
transporting loudspeakers that they are nowhere near equipment and
objects which may be impaired or damaged by an external magnetic
field. Generally speaking, a distance of 0.5 m (1.5 ft) from magnetic
data carriers (floppy disks, audio and video tapes, bank cards, etc.) is
sufficient; a distance of more than 1 m (3 ft) may be necessary with
computer and video monitors.

J-INFRA Manual (1.1 EN) Safety precautions - 1

J-INFRA loudspeaker

J-INFRA

The J-INFRA is the cardioid infra subwoofer for the J-Series. It can be
used to supplement J-Series systems consisting of J8, J12 and J-SUB
cabinets in various combinations. It extends the frequency response of a
J-Series system down to 27 Hz

J-INFRA cabinets can be used ground stacked in a conventional L/R
setup as well as arranged in a subwoofer array. One J-INFRA cabinet
provides additional very low frequency energy for two J-SUB
subwoofers.

A detailed description of planning and designing J arrays is given in the
technical information “TI 385 d&b Line array design, ArrayCalc” which is
provided with the J Flying frame and the d&b ArrayCalc Simulation
software.

The J-INFRA cabinet is an actively driven 2-way bass-reflex design
housing three long excursion neodymium 21“ drivers, two drivers face
to the front while one driver radiates to the rear of the cabinet.

Front and rear drivers are driven by separate amplifier channels and
operate in independent bass reflex chambers. Through its cardioid
dispersion pattern this setup avoids unwanted energy behind the system
and greatly reduces the reverberant field at low frequencies providing
highest accuracy in low frequency reproduction. J-INFRA cabinets have
to be arrayed with a minimum distance of 60 cm (2 ft) between
adjacent cabinets.

1
2
3
4
5

Sense Drive

Connector wiring

The J-INFRA cabinet is constructed from marine plywood and has an
impact and weather protected PCP (Polyurea Cabinet Protection) finish.
The front and rear of the loudspeaker cabinet are protected by a rigid
metal grill. The side panels incorporate eight handles. Two runners
extend from the rear to the front panel of the cabinet protecting the
bottom panel against scratching. Two correspondingly shaped recesses
are incorporated in the top panel of each cabinet to accept these
runners and prevent cabinet movement when stacking J-INFRAs. The
cabinet front is fitted with four catches for securing an optional
transport lid E7920.

Connections

The J-INFRA cabinet is fitted with a single NLT4F connector. It uses the
pin assignments 1+/1– for the front drivers. Pins 2+/2– drive the rear
driver.

The J-INFRA can be supplied with an EP5 or NL8 connector as an
option. Pin equivalents of NLT4F, EP5 and NL8 connectors are listed in
the table below.

NLT4F

EP5

LF +

Front

1+ 1– 2+ 2– n.a.

1 2 3 4 5

LF –

Front

LF +

Rear

LF –

Rear

SenseDrive

Front

NL8

1+ 1– 4+ 4– 3–

J-INFRA Manual (1.1 EN) Page 4 of 8

Operation

INPUT A

OUT A
2-Way

SenseDrive

OUT B
2-Way

AMP B

AMP A

NOTICE!

Input/Output routing 2-Way Active mode

Only operate J-INFRA loudspeakers with a d&b amplifier configured for
the J-INFRA, otherwise there is a risk of damaging the loudspeaker
components.

When "2-Way Active" and J-INFRA mode are selected, each pair of
amplifier output channels drives a single J-INFRA cabinet.

The input signal is fed to one amplifier channel, while the input signal is
routed (linked) to the second channel internally.

With D12 amplifiers, to enable SenseDrive the loudspeaker cabinet has
to be connected to output A.

The two channels are tuned to create a cardioid dispersion pattern thus
providing maximum rejection to the rear.

Controller settings

When J-INFRA cabinets are placed close to J-SUB cabinets the standard
mode is selected.

70 Hz circuit

When J-INFRA cabinets are located remotely from J-SUB cabinets there
is less coupling between the systems. Selecting the 70 Hz circuit
compensates for this effect by extending the upper frequency limit to
70 Hz.

Cardioid polar pattern

Hypercardioid polar pattern

HCD circuit

Selecting HCD (Hypercardioid) optimizes the tuning of front and rear
channels for a maximum rejection at the left and right sides behind the
cabinet providing a hypercardioid dispersion pattern. This characteristic
is particularly useful for a setup with subwoofers stacked at the left and
right sides of a stage providing minimum interference onstage.

HCD mode can be used either freely radiating or in front of walls. The
minimum distance to rear walls is provided by the wheels on the cabinet
back. Even in HCD mode adjacent J-INFRAs have to be at least 60 cm
(2 ft) apart.

J-INFRA Manual (1.1 EN) Page 5 of 8

J-INFRA frequency response,
standard and 70 Hz settings

Technical specifications

J-INFRA system data

Frequency response (–5 dB standard).................................................27 Hz ... 60 Hz

Frequency response (–5 dB 70 Hz mode)...........................................27 Hz ... 70 Hz

Max. sound pressure (single cabinet, 1 m, free field)

with D80....................................................................................................................144 dB

with D12....................................................................................................................141 dB

(SPLmax peak with music program)

J-INFRA loudspeaker

Nominal impedance front/rear........................................................................3/6 ohms

Power handling capacity front (RMS / peak 10 ms).........................1200/4800 W

Power handling capacity rear (RMS / peak 10 ms)............................600/2400 W

Components..................................................................................................3 x 21” driver

Connections..............................................................................................................1 x EP5

.................................................................................................................(optional 1 x NL8)

Pin assignments

NLT4F..................................................1+: Front+/1–: Front–/2+: Rear+/2–: Rear–

EP5.............................1: Front+/2: Front–/3: Rear+/4: Rear–/5: SenseDrive front

NL8..............1+: Front+/1–: Front–/4+: Rear+/4–: Rear–/3–: SenseDrive front

Weight..........................................................................................................................152 kg (335 lb)

J-INFRA cabinet dimensions in mm [inch]

J-INFRA Manual (1.1 EN) Page 6 of 8

Manufacturer's Declarations

EU conformity of loudspeakers (CE symbol)

This declaration applies to

- J-INFRA loudspeaker Z1000

manufactured by d&b audiotechnik GmbH.

All production versions of this type are included, provided they
correspond to the original technical version and have not been subject
to any later design or electromechanical modifications.

We herewith declare that said products are in conformity with the
provisions of the respective EC directives including all applicable
amendments.

A detailed declaration is available on request and can be ordered from
d&b or downloaded from the d&b website at

WEEE Declaration (Disposal)

Electrical and electronic equipment must be disposed of separately from
normal waste at the end of its operational lifetime.

Please dispose of this product according to the respective national
regulations or contractual agreements. If there are any further questions
concerning the disposal of this product please contact d&b audiotechnik.

www.dbaudio.com.

J-INFRA Manual (1.1 EN) Page 7 of 8

D2984.EN .01, 01/2014 © d&b audiotechnik GmbH

d&b audiotechnik GmbH, Eugen-Adolff-Str. 134, D-71522 Backnang, Germany, Phone [phone], Fax [phone]