Electro-Voice XCB EDS User Manual

Xcb

X-Array™ Bass System

• Single-woofer design equivalent
to half of an Xb

• Ring Mode Decoupling (RMD)™
provides accurate transient detail

• EVX-180B woofer

• Unique rear-hinge rigging

• Enclosure shell and rigging
identical to all of the half-size
X-Array™ systems

Description

The X-Array™ product line represents im­portant advancements in concert-sound-rein­forcement technology. The design goals
called for the highest acoustic output capa­bility with the highest fidelity in lightweight,
compact enclosures that were easy to array.
The development began with a clean sheet
of paper and took an integrated approach.
The individual loudspeaker drivers, horns,
enclosures, rigging hardware and system
configurations were designed from the
ground up specifically for this high-perfor­mance application.

The Xcb is a manifolded, vented-box bass
system utilizing one 457-mm (18-in.) woofer
in the half-size X-Array™ enclosure shell.
The one woofer faces into a slotted cham­ber at the bottom of the enclosure. This tech­nique increases the acoustic loading, result­ing in increased low-frequency efficiency (at
slightly above box tuning) and reduced dis­tortion compared to conventional direct-ra­diating designs. The woofers were designed
as part of the Xcb development and repre­sent a step forward in state-of-the-art loud­speaker design in terms of high acoustic out­put with low distortion and low power com­pression. Electro-V oice engineers developed
a new technology dubbed Ring Mode
Decoupling (RMD™) to substantially im­prove clarity and intelligibility by reducing

both linear and nonlinear resonance modes
that color the sound.

The low-frequency driver in the Xcb is the
EVX-180B. An improved version of the in­dustry-standard EVX-180A high-excursion
467-mm (18-in.) woofer that has distin­guished itself as an industry standard for
high-power, low-frequency reproduction.
During the X-Array™ development, the ther­mal conduction of the motor was improved
and the suspension was redesigned, giving
the EVX-180B even lower power compres­sion and a longer mechanical lifetime. In the
Xcb, the woofer is slot-loaded in a vented
enclosure optimized for maximized output
from 37-160 Hz with minimized distortion.

Ring Mode Decoupling, (RMD™), is a tech­nique utilized and named by Electro-Voice
to describe a process used to improve sound
quality in loudspeaker systems.

Ring Mode Decoupling (RMD™) offers a
solution to a very fundamental problem. It
has long been recognized that two different
loudspeaker systems can sound different
even though they both may be equalized to
have the same frequency response. This dif­ference is due to a variety of resonances, or
ring modes that color the sound. Although
this ringing may be very low in level com­pared to the program material, it is still au­dible. The source of these resonances may
be mechanical or acoustical in nature, or a

combination of both. In addition, they may
be linear or nonlinear, resulting in their char­acter changing with level. Furthermore, these
Ring Modes may be aggravated when mul­tiple loudspeaker enclosures are assembled
into arrays. The result is a coloration that de­creases intelligibility and clarity, with the
nature of that coloration varying with level.
Often, the listener perceives that coloration
as imbalance in the frequency response, and
will attempt to electronically adjust the sys­tem to restore the spectral balance. However
this electronic equalization has the negative
effect of changing the program material
itself.

Ring Mode Decoupling (RMD™) ad­dresses mechanical resonances with me­chanical solutions, and acoustical reso­nances with acoustical solutions. In the
Xcb development, RMD™ was applied at
every level – to the individual low-fre­quency drivers, the low-frequency enclo­sure chambers and the interaction between
multiple enclosures. The design process
included, for example, the driver cone, sus­pension geometry and materials, enclosure
geometry and materials, absorptive mate­rials, etc. The result is a dramatic improve­ment in clarity and with a much more neu­tral sound (a lack of coloration) with the
loudspeaker system maintaining its sonic
integrity from the very-lowest sound pres­sure levels to the very-highest sound pres-

Xcb Bass System

sure levels. This means that the front-of­house engineer will not have to retune the
EQ and level settings as the SPL is in­creased throughout the show. This also
means that the sound-system performance
will remain consistent in different array con­figurations and from venue to venue.

The X-Array™ systems utilizes a unique rig­ging system. A hinge assembly is used to link
cabinets together at their rear corners, while
wire-rope/fitting assemblies are used at the

Xcb Bass System

front to adjust the relative angle between sys­tems. (See the Flying the X-Array™ Systems
section for more details.)

The Xcb utilizes the half-size X-Array™ en­closure shell, which is identical to that of
the Xcn mid-bass/high-frequency system.
They have the same footprint and rigging as
the full-size X-Array™ systems; however,
the height of the compact systems is approxi­mately half that of the full-size systems.

The durable Xcb enclosure is constructed of
18-mm, 13-ply birch plywood and has a
wear-resistant black, textured paint finish.
The system is trapezoidal, forming an 18°
wedge and includes a heavy-duty steel grille
with a water-resistant charcoal-gray foam in­terlining. The enclosure features vinyl
bumper pads on the front corners to and feet
on the bottom to resist wear.

A variety of accessories are available for the
X-Array™ loudspeaker systems, including
rigging hardware, dollies, covers, electronic
crossovers, amplifier racks and speaker ca­bling. Consult the X-Array™ Accessories
section for a complete listing of the avail­able accessories

Applications

The X-Array™ loudspeaker systems were
designed for optimal performance in both
concert-sound and permanent-installation
applications where studio-monitor sound
quality is required at concert-sound levels.
The X-Array™ loudspeaker systems work
well individually, in small arrays and in lar ge
arrays. The high acoustic output from these
compact, lightweight systems provide the
highest acoustic-power-to-weight ratio, the
highest acoustic-power-to-frontal-area ratio,
and the highest acoustic-power-to-bulk-vol­ume ratio in the industry. That means that
X-Array™ systems will be considerably
smaller and lighter compared to competitive

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systems having equivalent acoustic out­put.

With its response from 37-160 Hz, the Xcb
is recommended for low-frequency appli­cations where very-high levels of bass are
required from a compact enclosure. Spe­cifically, the Xcb has been optimized to pro­vide low-frequency reinforcement for the
LF/MB/HF and MB/HF X-Array™ sys­tems (like the Xf, Xn or Xcn). The Xcb may
be used individually or in multiples to con­struct low-frequency arrays, or may be
used with the mid-bass-/high-frequency or
low-/mid-bass-/high-frequency X-Array™
loudspeaker systems to construct large
full-range arrays. The Xcb enclosure is
identical to that of the other half-size X­Array™ systems (like the Xcn). The foot­print of the half-size X-Array™ enclosures
is identical to that of the full-size X-Ar­ray™ systems (like the Xn, Xf and Xb), as
is the rigging hardware, making array inte­gration easy whether flying or stacking.

The Xcb would be well suited for front-of­house, front-fill, side-fill applications and
down-fill applications. The Xcb is intended
to be used with other X-Array™ systems for
a full-range response as an active system that
requires an active electronic crossover. Both
the Electro-Voice Dx38 and Klark Teknik
DN8000 digital crossovers are recom­mended for signal control. (See the Cross-

over, Equalization and Signal Delay Con­troller section.) The Electro-Voice P3000

amplifier is recommended for powering the
Xcb. (See the Amplifier Recommendations
section.)

Power-Handling Capabilities

The Xcb systems are rated as per the
“ANSI/EIA RS-426-A Loudspeaker Power­Rating, Full-Range Test,” which uses a
shaped-random-noise signal to simulate
typical music to test the mechanical and
thermal capabilities of the loudspeakers.
A digital crossover was used to provide
the appropriate filtering and equalization.
The test parameters are as follows:

Low-Frequency Section

P

: 600 watts

E(MAX)

Test Voltage: 58.7-volts rms

117.4-volts peak

R

(1.15RE): 5.75 ohms

SR

Amplifier Recommendations

Power amplifiers with the following ratings
are recommended for use with the Xcb loud­speaker systems:

LF: 800 watts per channel

into 8 ohms
93-volts rms short term
132-volts peak

Xcb loudspeakers may be paralleled with
other Xcb systems as long as the amplifiers
can drive the lower impedances. To main­tain a sufficient damping factor with long
cable runs, amplifier loads of four ohms per
channel are recommended. The Electro­Voice P3000 amplifiers are ideal for power­ing the X-Array™ systems.

Crossover, Equalization and Signal
Delay Controller

The Xcb is intended to be used with other
X-Array™ loudspeaker systems (like the Xf,
Xn, Xb or Xds for example) to construct full­range arrays as an active system requiring
an active crossover, equalization and signal
delay controller. For basic applications, the
Electro-Voice Dx38 2-in/4-out controller is
recommended. For more sophisticated ap­plications, the Klark Teknik DN8000 2-in/
5-out controller is recommended. Linkwitz­Riley crossover filters with a minimum slope
of 24 dB per octave at 125 Hz are recom­mended, and infrasonic filter protection at
42 Hz or higher with a minimum slope of
12-dB/octave is recommended in the low­frequency section. Both the Dx38 and the
DN8000 offer appropriate filtering, equal­ization and signal delay capabilities to pro­vide optimum performance of the X-Ar­ray™ loudspeaker systems. Digital param­eter settings for both controllers are avail­able upon request.

Electrical Connection and System
Wiring

T wo semi-paralleled Neutrik 8-pin Speakon
connectors are used for electrical connection
to the Xcb loudspeakers with the following
pin assignments:

LF1: Pins 1 in/ Pins 2 out

The Xcb wiring diagram is shown in Fig­ure 7. Note that one connector is specifi­cally labeled for input connection only and

®

Xcb Bass System

the other for output connection only. Also
note that Pins 1 In are connected to Pins 2
Out, and Pins 2 In are connected to Pins 1
Out. This facilitates the wiring of multiple
systems with amplifiers. When four Xcb
systems are jumped from one to another
via the input/output connections, the am­plifier home-run cable will have two woof­ers on Pins 1 (for a 4-ohm load) and two
woofers on Pins 2 (for a 4-ohm load). Al­though Pins 3 and 4 are not used by the
Xcb systems, they are paralleled on the
input panel. This allows an X-Array™ MB/
HF box (like the Xcn or Xf – which use
Pins 1 and 2, but not Pins 3 and 4) to be
paralleled with an Xcb, allowing all eight
conductors to be used with a single cable
run to the amplifiers.

Flying the X-Array™ Systems

The X-Array™ loudspeaker systems all
utilize the same rigging hardware and have
the same structural strength ratings. Thus,
different systems may be mixed in an array
to achieve the best acoustic results. The
rigging system allows for the smallest pos­sible spacing between adjacent enclosures,
and utilizes quick-release rigging fittings
for fast installation and tear down.

When flown, the X-Array™ enclosures are
linked together by two removable hinges on
the rear of the enclosures at the top and bot­tom. This arrangement enables the enclo­sures to pivot vertically from the rear cor­ners. The relative vertical angle between
adjacent enclosures is adjustable and set by
two removable rigging straps on the front of
the enclosures at the top and bottom. Both
the rear rigging hinges and the front rigging
straps are installed when enclosures are sit­ting on top of one another. For ease of in­stallation of the hinges and straps, the en­closures self align using feet and cups
mounted on the top and bottom of the en­closures. The relative horizontal angle be­tween adjacent columns of loudspeakers is
set by adjustable grids at the top of the array
(or by custom-building attachment supports
in permanent-installation applications where
grids are not used).

The removable proprietary rear rigging
hinges utilize all-steel construction, and are
secured into a proprietary track assembly on
the enclosure (similar to the heavy-duty air­craft L-track). The aluminum track is ex-

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truded as a single-piece track/angle-bracket
assembly and ties into the top, bottom and
rear of the enclosure. Metal bars inside the
enclosure tie the top and bottom track/angle­bracket assemblies together, minimizing the
load applied to the wooden enclosure. The
rear extrusion will accommodate the New
Haven 32102-2 aircraft-type double-stud
locking fitting instead of the hinge for ap­plications requiring a lower strength rating.

The removable, front strap assemblies uti­lize all-steel New Haven 32102-2 aircraft­type double-stud locking fittings and wire­rope and are secured into another proprietary
track similar to the heavy-duty aircraft L­track. The track is extruded as a single-piece
track/angle-bracket assembly that ties into
the front and side of the enclosure. The track/
angle-bracket assembly extends from the top
to the bottom of the enclosure, eliminating
the load applied to the wooden enclosure.

A complete line of flying-hardware acces­sories is available for the X-Array™ loud­speaker systems including a grid, rigging
hinges and rigging straps. The variety of rig­ging hinges and front rigging straps avail­able include those for linking two enclosures
together, securing the top enclosure in a col­umn to a grid and for picking up the top en­closure in a column without a grid. Consult
the X-Array™ Accessories section for a com-
plete listing of the available rigging acces­sories.

The total weight of a column of X-Array™
loudspeaker systems that may be supported
by the X-Array™ rigging system varies from
454-726 kg (1,000-1,600 lb) depending on
the rigging configuration details. An X­Array™ Flying Manual is available from
Electro-Voice and is included with each
X-Array™ system shipment. The manual
should be consulted for complete structural
specifications and detailed instructions for
safely suspending and using the X-Array™
systems.

Field Replacement

Normal service for the Xcb requires only a
#2 Phillips screwdriver and a 3/16-inch hex­key wrench. The drivers may be accessed
as follows:

LF: First remove the grille, then remove
the screws securing the hatch on the front
of the enclosure. Remove the screws se-

curing the 18-inch woofer and lift the
woofer out of the enclosure. In the event
of failure, the entire woofer must be re­placed or reconed.

The following service parts are available
from the service department in Buchanan,
Michigan USA:

LF #818-2883 EVX-180B complete driver
The complete drivers are available only for

repair replacement and are not available for
general sale.

Architects’ and Engineers’
Specifications

The loudspeaker system shall be a two­driver, slot-loaded, vented-box low-fre­quency system with a frequency response
from 37-200 Hz. The loudspeaker system
also shall have one 457-mm (18-in.) low­frequency woofers and each shall have an
8-ohm, 101-mm (4-in.) diameter voice
coil and a 600-watt power rating. The loud­speaker shall have a rigging system enabling
a column of loudspeakers to be hinged at
their back corners, with relative downward
angles set by adjustable rigging straps at the
front.

The enclosure shall be constructed of 18-mm
thick, 13-ply birch plywood, and shall be
trapezoidal, forming an 18° wedge and be
596 mm (23.46 in.) high, 584 mm (23.00 in.)
wide at the front, 354 mm (13.93 in.) wide
at the back and 759 mm (29.88 in.) deep,
and shall weigh 55.8 kg (123 lb).

The loudspeaker system shall be the
Electro-Voice Xcb.

Rigging Accessories:
Grid: This ATM Fly-Ware™ “T”–shaped,

all-steel-construction grid was specifically
designed as a single column of X-Array™
systems. Multiple grids can be linked to­gether with couplers on front and back re­tractable arms, the position of which sets the
splay angle between adjacent columns. Part
number MEGS-4000-T. ATM Fly-ware™,
2100 S. Wilmington A ve., Carson, CA 90810
USA, 310/834-5914

Xrhg Grid Hinge: Two Xrhg grid rigging
hinges are used to attach the rear of the
top enclosure in a column to the rear of an
X-Array™ compatible grid. Each hinge
consists of two precision-machined steel
rigging-track fittings connected by an al-

Xcb Bass System