Electro-Voice 2181F User Manual

Description
The X-Array Install™ product line repre-
sents important advancements in concert-
sound-reinforcement technology. The design
goals called for the highest acoustic output
capability with the highest fidelity in light-
weight, compact enclosures that were easy
to array. The development began with a clean
sheet of paper and took an integrated ap-
proach. The individual loudspeaker drivers,
horns, enclosures, rigging hardware and sys-
tem configurations were designed from the
ground up specifically for this high-perfor-
mance application.
The Xi-2181 is a manifolded, vented-box
bass system utilizing two 457-mm (18-in.)
woofers. The two woofers face each other
in a manifold chamber at the center of the
enclosure. This manifolding technique (U.S.
Patent Number 4,733,749) 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 Xi-2181
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-Voice 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 Xi-2181 is
the EVX-180B. An improved version of the
industry-standard EVX-180A high-excur-
sion 467-mm (18-in.) woofer that has dis-
tinguished itself as an industry standard for
high-power, low-frequency reproduction.
™
During the X-Array development, the ther-
mal conduction of the motor was improved
and the suspension was redesigned, giving
the EVX-180B even lower power compres-
sion and a longer mechanical lifetime. In the
Xi-2181, the woofers are manifolded in a
vented enclosure optimized for maximized
output from 37-160 Hz with minimized dis-
tortion.
Ring-Mode Decoupling, (RMD
nique utilized and named by Electro-Voice
to describe a process used to improve sound
quality in loudspeaker systems. RMD
fers a solution to a very fundamental prob-
lem. It has long been recognized that two
different loudspeaker systems can sound dif-
ferent even though they both may be equal-
ized to have the same frequency response.
This difference is due to a variety of reso-
nances, or ring modes that color the sound.
Although this ringing may be very low in
level compared to the program material, it is
Xi-2181/2181F
X-Array™ Install
Bass System
• Unprecedented acoustic output in
a small, lightweight package
• Ring-Mode Decoupling (RMD)™
provides accurate transient detail
• EVX-180B woofers
• Unique rear-hinge rigging
• Flying and non flying configuration
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 as-
sembled into arrays. The result is a colora-
tion 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 re-
sponse, and will attempt to electronically
adjust the system to restore the spectral bal-
ance. However this electronic equalization
has the negative effect of changing the pro-
gram material itself.
Ring-Mode Decoupling (RMD
mechanical resonances with mechanical
™
), is a tech- solutions, and acoustical resonances with
acoustical solutions. In the Xi-2181 devel-
opment, RMD
™ of- 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 mate-
rials, enclosure geometry and materials, ab-
sorptive materials, etc. The result is a dra-
matic improvement in clarity and with a
much more neutral sound (a lack of colora-
tion) with the loudspeaker system maintain-
™
) addresses
™
was applied at every level –