Electro-Voice FRX-940 User manual

Description
The Electro-Voice FRX-940 is a two-way,
high-efficiency, horn-loaded speaker system
designed for indoor sound reinforcement in
fixed installations such as churches, meeting
halls and auditoriums. Capable of producing
sound pressure levels (SPL) in excess of 124
dB at 1 meter, the FRX-940 will give full-
bandwidth reproduction without sacrificing
sonic quality. The FRX-940 features a
90°x 40°horn. TheDH2Tcompression driver
providessmooth, extended response to 20 kHz
andfeatures atitanium diaphragmand aunique
convex-driveTime Path™ phasing-plug struc-
ture (U.S Patent #4,525,604).
The optimally vented bass section of the
FRX-940 is designed using Theile-Small pa-
rameters for efficient performance to below
50 Hz and utilizes a 400-watt DL15-FRX
15-inchwoofer to provide high excursion with
low coloration.
TheFRX-940 is providedwith apassive cross-
over which features 12-dB/octave slopes cen-
tered acoustically at 1,800 Hz and EV’s self-
resetting PRO™ circuit to guard the compres-
sion driver against damage. The system can
beeasily converted tobe operated in the biamp
mode by removing the input-panel assembly
(eight screws) and moving the four jumpers
as indicated on the crossover. When used in
biamp mode the woofer uses pins 1+ and 1–
and the tweeter uses pins 2+ and 2–.
The enclosure is constructed from seven-ply
plywood and is available in three alternative
finishes;FRX-940 BLK(black textured paint),
FRX-940 UN (unfinished and ready to stain)
and FRX-940 WH (white textured paint).
The grille is constructed from 16-gauge
powder-coated steel and is backed with foam.
Ring-Mode Decoupling (RMD™)
The FRX-940 controls both acoustical and
mechanical ring modes to provide dramati-
cally increased intelligibility, using tech-
niques learned from the development of the
Electro-Voice X-Array™ concert speakers.
There is much less coloration of the sound
from resonating sources, leaving only the
intended sound to be heard by the audience.
Frequency Response
The FRX-940 axial frequency response was
measured in Electro-Voice’s large anechoic
chamber at a distance of 10 feet with a swept
sine-wave input (see Figure 1). The response
curves show response with the passive cross-
over and with the FRX-940 in the biamped
mode with presets for the Electro-Voice
DX34A digital loudspeaker processor. On
Axis, one watt calculated using Ez/Zmin, 3.16-
meter measurement distance referred to one
meter.
Directivity
The directional characteristics of the FRX-940
were measured in Electro-Voice’s large
anechoic chamber. The test signal was one-
third-octave filtered pink noise at the frequen-
cies indicated. A full spherical measurement
system was used. All directional information
was measured at 20 feet.
Figure 2 illustrates the horizontal and vertical
polar responses with the internal crossover in
the passive mode.
Figure 3 shows the horizontal and vertical
beamwidths. Beamwidth is the angle at which
thehorizontal andvertical polarresponses have
decreased in level by 6 dB when compared
with the axial frequency response.
Figure 4 illustrates the total directivity of the
FRX-940. The directivity factor Rθ(Q) is the
relative value, at a point, of the FRX-940 out-
put when compared to an ideal spherical re-
sponse. The directivity index, Di, is calculated
by Di= 10 log10Rθ.
Power-Handling Test
Electro-Voice components and systems are
manufactured to exacting standards, ensuring
FRX-940
High-Output,
Two-Way,Horn-Loaded
Coaxial Speaker System
• 15-inch woofer
• 90° x 40° coverage
• Vented LF horn design delivers
rated control to 500 Hz
• 400-wattslong-termpowercapacity
• Ring-Mode Decoupling (RMD™)
• Available in black (BLK) unfin-
ished (UN) and white (WH)
• Full-range or biamp operation
with internal passive crossover
• DH2T 1-inch-exit titanium
compression driver
• Built-in L-track rigging

2
FRX-940 High-Output, Coaxial Speaker System
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
they will hold up, not only through the most
rigorous of power tests, but also through con-
tinueduse in arduous, real-lifeconditions. The
EIA Loudspeaker Power Rating Full Range
(EIA RS-426-A 1980) uses a noise spectrum
which mimics typical music and tests the ther-
mal and mechanical capabilities of the com-
ponents. Electro-Voice will support relevant
additionalstandards as they becomeavailable.
Extreme,in-house power tests,which push the
performanceboundaries ofthe system,are also
performed and passed to ensure years of
trouble-free service.
Specifically, the FRX-940 passes EIA RS-426-A
1980 with the following values:
RSR = (1.15 x RE) = 6.9 ohms
PE(MAX) = 400 watts
Test voltage = 52.5 volts rms,
105 volts peak
The "peak" power-handling capacity of a
woofer is determined by the peak test voltage
amount. For the FRX-940 a 105-volt peak test
voltagetranslates intoa 1,600-watt short-term-
peak power-handling capacity. This is the
equivalent of four times the "average" power-
handling capacity, and is a peak that can be
sustained for only a few milliseconds. How-
ever, this sort of short duration peak is very
typical in speech and music. Provided the
amplifier can reproduce the signal accurately,
without clipping, the system will also perform
accurately and reliably, even at these levels.
Suspending the FRX-940
Thequick-release,aircraft-rated heavy-duty
L-track-type hardware design allows arrays
of loudspeakers to be assembled very
quickly, and offers such flexibility in the
vertical angling of cabinets that pull-up
points are usually unnecessary. However,
if the need for pull-up points is required,
two 3/8-16 threaded nuts are located on the
rear of enclosure for this purpose.
Additional flying hardware is installed on
thebottomofthe enclosure for arraying pur-
poses. However, a maximum of two FRX
enclosures (304 lb max.) can be "daisy-
chained"together, allowing the construction
of vertical arrays. If longer arrays are re-
quired, or for loads exceeding the 304-lb
maximum load limit, provision must be
made to independently suspend each enclo-
sure.
Fittingsarenotincludedinthesystempack-
aging. Contact the following to purchase:
Ancra International, 3300 Turfway Rd.,
Erlanger, KY 41018, 800/233-5138 or
Sound Manufacturing, 3336 Primera Ave.,
Hollywood,CA90068-1550, 231/850-5042
Suspendingan object is potentiallydanger-
ous and should only be attemped by indi-
viduals who have a thorough knowledge of
the techniques and regulations of rigging
objects ovehead. It is the responsibility of
theinstallerto ensurethe FRX-940 issafely
installed in accordance with applicable
regulations. If the FRX-940 is suspended,
Electro-Voicestronglyrecommendsthatthe
system be inspected at least once a year. If
anysign of weaknessordamage is detected,
remedial action should be taken immedi-
ately.
Architects' and Engineers' Specifications
The loudspeaker system shall be a coaxial,
two-way full-range design consisting of a 15-
inch woofer, a high-frequency compression
driver on a fiberglass molded constant-direc-
tivity horn and a dividing network providing
an acoustic crossover frequency of 1,800 Hz.
The system shall be configurable in a biamp
mode through internal switches in the cross-
over network. The loudspeaker shall meet the
following performance criteria; power han-
dling, 400 watts, based upon ANSI/EIA RS-
426-A 1980 standard for full-range loud-
speaker systems; frequency response, smooth
and usable at high SPL levels from 50 Hz to
20kHz; pressure sensitivity, 101dB SPL (pas-
sive mode) or 105 dB (LF)/109 (HF) in
biamp mode for 1 W at 1 m; impedance, 8
ohms nominal, 5 ohms minimum. The sys-
tem shall have a distribution pattern with
90°nominal horizontally from 3 kHz to
20 kHz and 40°nominal vertically from 3
kHz to 20 kHz. The enclosure shall be con-
structed from plywood and braced appropri-
ately, and the grille will be constructed from
powder- coated steel, backed by a weather-
resistant foam. The dimensions shall be 78.7
cm (31.0 in.) high by 71.9 cm (28.3 in.) wide
by 66.0 cm (26.0 in.) deep. Net weight shall
be 68.95 kg (152 lb). The system shall be
the Electro-Voice FRX-940 BLK (black
texturlac paint with black grille), or the FRX-
940 UN (unfinished ready for staining with
black grille), or the FRX-940 WH (white
texturlac paint with white grille).
Limited Warranty
Electro-Voice products are guaranteed against
malfunction due to defects in materials or
workmanship for a specified period, as noted
in the individual product-line statement(s)
below, or in the individual product data sheet
or owner’s manual, beginning with the date
of original purchase. If such malfunction oc-
curs during the specified period, the product
will be repaired or replaced (at our option)
without charge. The product will be returned
to the customer prepaid. Exclusions and
Limitations: The Limited Warranty does not
apply to: (a) exterior finish or appearance; (b)
certain specific items described in the indi-
vidual product-line statement(s) below, or in
the individual product data sheet or owner’s
manual; (c) malfunction resulting from use
or operation of the product other than as speci-
fied in the product data sheet or owner’s
manual; (d) malfunction resulting from mis-
use or abuse of the product; or (e) malfunc-
tion occurring at any time after repairs have
beenmade to the product by anyone otherthan
Electro-Voice Service or any of its authorized
service representatives. ObtainingWarranty
Service: To obtain warranty service, a cus-
tomer must deliver the product, prepaid, to
Electro-Voice Service or any of its authorized
service representatives together with proof of
purchase of the product in the form of a bill
of sale or receipted invoice. A list of autho-
rized service representatives is available from
Electro-Voice Service at 600 Cecil Street,
Buchanan, MI 49107 (800/234-6831 or FAX
616/695-4743). Incidental and Consequen-
tial Damages Excluded: Product repair or
replacement and return to the customer are
the only remedies provided to the customer.
Electro-Voice shall not be liable for any inci-
dental or consequential damages including,
without limitation, injury to persons or prop-
erty or loss of use. Some states do not allow
theexclusion orlimitation of incidentalor con-
sequential damages so the above limitation or
exclusion may not apply to you. Other

FRX-940 High-Output, Coaxial Speaker System
3
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
Figure 1— Axial Frequency Response
(anechoic environment, 1 watt at 1
meter)
Rights: This warranty gives you specific le-
gal rights, and you may also have other rights
which vary from state to state.
Electro-Voice Speakers and Speaker Sys-
tems are guaranteed against malfunction due
to defects in materials or workmanship for a
period of five (5) years from the date of origi-
nal purchase. The Limited Warranty does not
apply to burned voice coils or malfunctions
suchas coneand/or coil damageresulting from
improperlydesigned enclosures. Electro-Voice
active electronics associated with the speaker
systemsare guaranteedfor three (3)years from
the date of original purchase. Additional de-
Dx34A processor (biamp mode)
Passive crossover
tailsare included in theUniform Limited War-
ranty statement.
For warranty repair or service information,
contact the service repair department at:
616/695-6831 or 800/685-2606.
For technical assistance, contact Technical
Support at 800/234-6831 or 616/695-6831,
M-F, 8:00 a.m. to 5:00 p.m. Eastern Standard
Time.
Specifications subject to change without
notice.
Dx34A processor (biamp mode)
Passive crossover

4
FRX-940 High-Output, Coaxial Speaker System
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
Figure 2—One-Third-Octave Polar
Response (anechoic environment, with
passive crossover, long box axis
vertical)
HORIZONTAL
VERTICAL
5dBper Division

FRX-940 High-Output, Coaxial Speaker System
5
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
5 dB per Division HORIZONTAL
VERTICAL

6
FRX-940 High-Output, Coaxial Speaker System
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
Figure 3—Beamwidth vs.
Frequency (anechoic environment,
with passive crossover, long box axis
vertical)
Figure 4—Directivity vs.
Frequency (anechoic environment,
with passive crossover)
Figure 5—Harmonic Distortion, 0.1
Rated Power Input (40 watts)
(anechoic environment, with passive
crossover)
Fundamental
2nd Harmonic
3rd Harmonic
Fundamental
2nd Harmonic
3rd Harmonic

FRX-940 High-Output, Coaxial Speaker System
7
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
Figure 6—Impedance (anechoic
environment, log scale)
Figure 7—FRX-940 Dimensions

8
FRX-940 High-Output, Coaxial Speaker System
FR10-2B SPECIFICATION GRAPHICS
FRX-940 High-Output, Coaxial Speaker System
Part Number 535265 – 9903
600 Cecil Street, Buchanan, MI 49107
616/695-6831, 616/695-1304 Fax
© Telex Communications, Inc., 1999 • Litho in U.S.A.
Specifications
Axial Frequency Response (swept
sine wave, 4 volts at 10 feet on axis,
anechoic environment normalized for
1 watt/1 meter; see Figure 1):
50-20,000 Hz
Low-Frequency 3-dB-Down Point:
50 Hz
Usable Low-Frequency Limit (10-dB-
down point):
43 Hz
Half-Space Reference Efficiency:
4.5%
Long-Term Average Power-Handling
Capacity (per ANSI/EIA RS-426-A
1980; see Power-Handling Capacity
section):
400 watts
Maximum Woofer Acoustic Output:
17.6 watts
Sensitivity (SPL at 1 m, 1 W into
nominal impedance, anechoic
environment, band-limited pink-noise
signal, 100-15,000 Hz):
Passive:
101 dB
Bi-amp:
105 (LF)
109 (HF)
Beamwidth (passive mode, angle
included by 6-dB-down points on
polar responses, horizontal and
vertical planes, indicated one-third-
octave bands of pink noise; see
Figure 3),
2,000-16,000 Hz,
Horizontal:
90° +7°/–20°
Vertical:
40° +4°/–9°
Directivity Factor Rθθ
θθ
θ(Q), 500- to
16,000-Hz Median (see Figure 4):
21.7 (+21.3, –11.1)
Directivity Index Di, 500- to 16,000-Hz
Median (see Figure 4):
13.4 dB (+2.9 dB, –3.2 dB)
Transducer Complement,
Low-Frequency:
DL15-FRX 15-inch woofer
High-Frequency:
DH2T Driver
Box Tuning Frequency:
65 Hz
Crossover Frequency:
1,800 Hz acousticaly
Crossover Slope:
12 dB per octave
Impedance,
Nominal:
8 ohms
Minimum:
5.0 ohms
Input Connections:
Dual barrier strip
with screw terminals
LF/Full Range
1+/1–
HF/Biamp Mode
2+/2–
Enclosure Materials and Colors:
Seven-ply plywood with
removable grille
FRX-940 BLK
Black textured paint, black grille
FRX-940 UN
Unfinished (ready to stain),
black grille
FRX-940 WH
White textured paint, white grille
Grille:
Powder-coated steel backed
with foam
Suspension: See suspending the
FRX-940 section
Two-point heavy-duty L-track system,
accepts New Haven NH32102-2
double-stud fittings, New Haven
NH8192-2S or Ancra 42546-10
single-stud fittings with safety pins
(not included);
Contact the following to purchase:
Ancra International
3300 Turfway Rd.
Erlanger, KY 41018
800/233-5138
or
Sound Manufacturing
3336 Primera Ave.
Hollywood, CA 90068-1550
231/850-5042
Dimensions,
Height:
78.7 cm (31.0 in.)
Width:
71.9 cm (28.3 in.)
Depth:
66.0 cm (26.0 in.)
Net Weight:
68.95 kg (152 lb)
Shipping Weight:
71.21 kg (157 lb)
SPEAKERS—Full Range/Install