Electro-Voice S15 Specifications
S15
Two-Way Stage Speaker
System
• PROTM circuit provides HF driver
protection
• Integral stand mount
• Constant-directivity 60° x 40°
horn
• 250-watt long-term rms power
capacity
• Roadworthy enclosure with metal
corners, a metal grille and a
durable black-carpet finish
• Dual 1/4-inch phone jack or dual
Neutrik Speakon
1
See Connections section
®
inputs
1
Description
The Electro-Voice S15 is a 250-watt, two-way,
high-efficiency, constant-directivity stage
system featuring a vented, direct-radiating
woofer section. It combines professional
quality Electro-Voice components arranged
in an unusually durable, light-weight enclosure. The result is wide-range accurate sound
reproduction with transparent highs and extended bass response.
The high-frequency section of the S15 utilizes a 60° X 40° constant-directivity horn
driven by a one-inch throat, wide-bandwidth,
titanium-diaphragm driver. The DH2010A
uses a unique, convex-drive Time Path
phasing plug structure (U.S. Patent
#4,525,604) for smooth and extended highfrequency performance. The voice coil is
coupled to the diaphragm with EV’s exclusive Resonant Drive
creases and smooths the high-frequency response and reduces the amount of internal
equalization required for flat frequency response. Driver output extends to 20,000 Hz.
A self-resetting high-frequency protection
circuit, EV’s PRO
the S15 to prevent against accidental overdrive and improve system reliability. If the
TM
Technology . This in-
TM
circuit, is included with
TM
input power to the high-frequency driver
exceeds the nominal rating, the protection
circuit is activated and reduces the power
delivered to the driver by 6 dB. The system
will remain in this mode of operation until
the input power is reduced to a safe level.
The bass section of the S15 is designed using Thiele-Small parameters for solid performance to 52 Hz. The 381-mm (15-in.)
SG15 woofer used is a specially designed
unit featuring an extended length voice coil
and high-temperature construction materials.
The system combines professional-quality
components, arranged in an unusually durable Thiele-Small-aligned vented enclosure.
The result is clear and articulate, high-quality sound.
Speaker Protection
The S15, like all other vented systems, experiences rapidly increasing cone excursion
below the box-tuning frequency, while the
acoustic output decreases rapidly. Therefore,
to protect the S15 and maximize the power
output of the system, it is necessary to insert
an active 32- to 45-Hz high-pass filter into
the circuit. The filter should have a slope of
at least 12 dB per octave. Such subpassband
filters are found in many crossovers and
equalizers manufactured by Electro-Voice,
as well as other commercially available
equipment.
Enclosure Construction
The S15 enclosure is constructed of Road-
TM
Wood
the strength of high-quality plywood with the
density and acoustic damping of particle
board without brittleness. Road-Wood
uses the same principle of crossbanding
veneers, as in plywood, in order to achieve
its very high rigidity. A tough liquid-phenolic resin is blended with long, narrow
strands of hard-wood. Alternate layers are
perpendicularly bonded under intense heat
and pressure to form panels of superior uniformity. Unlike many grades of plywood,
Road-Wood
ter-resistant and free from voids.
A combination of dado cut joints and tough
adhesives ensure a sonically dead enclosure
free from panel resonances.
The densely-woven, industrial-grade, abuseresistant carpeting provides a finish that is
both attractive and highly durable. Heavyduty metal corner protectors, firmly secured
rubber feet, recessed handles and a protective metal grille complete the picture and
, a structural material that combines
TM
TM
is dimensionally stable, wa-
S15 Two-Way Stage Speaker System
ensure that the S15 speaker system is ideally suited to a long and reliable life on the
road.
Frequency Response
The combination of a 15-inch woofer, widebandwidth high-frequency driver and an
equalized crossover results in the wide and
smooth overall response shown in Figure 1.
This response was measured at 3.05 meters
(10 feet), using a 4-volt swept sine-wave input in an anechoic chamber. No external
equalization was used. Figure 1 has been
averaged and corrected for 1 watt at 1 meter.
Connections
S15 Two-Way Stage Speaker System
The S15 is equipped with two parallel
1/4-inch phone jacks. (The S15-E has two
parallel Neutrik Speakon
®
NL4MP connectors.) Another system can be connected in
parallel by using the other connector. Care
must be taken not to abuse the amplifier by
connecting impedances which are too low.
Constant-Directivity Speaker System
The crossover frequency and speaker component geometries have been selected so that
the directional characteristics of the woofer
and constant-directivity horn match at the
crossover frequency to create a special system type — the constant-directivity system.
At higher frequencies the horizontal coverage pattern remains constant and the vertical pattern smoothly transitions to a 40° angle
above 5,000 Hz. Response within the 60°x 40°
rated coverage angle is uniform, which
means dependable audience coverage without “hot spots” or dead zones at certain frequencies. The 60° x 40° dispersion characteristic also helps avoid early reflections from
nearby floor or side-wall surfaces which
could degrade performance. The controlled
directivity of the high- and low-frequency
transducers also eliminates response irregularities caused by diffraction off nearby enclosure edges and, in combination with an
essentially flat on-axis frequency response,
produces a total acoustic power output that
is uniform with frequency.
Directivity
A unique feature of the S15 is the constant-directivity dispersion provided by the 60° x 40°
horn. The polar response of the system at
selected one-third-octave bandwidths is
shown in Figure 5. These polar responses
were measured in an anechoic environment
at 6.1 meters (20 feet) using one-third-octave pink-noise inputs. The frequencies selected are fully representative of the polar
response of the system. Beamwidth of the
system utilizing the complete one-third-octave polar data is shown in Figure 6. Directivity factor, R
, and directivity index, Di, are
θ
plotted in Figure 7.
Power-Handling Capacity
Electro-Voice components and systems are
manufactured to exacting standards, ensuring they will hold up, not only through the
most rigorous of power tests, but also
through continued use in arduous, real-life
conditions. The EIA Loudspeaker Power
Rating Full Range (ANSI/EIA RS-426-A
1980) uses a noise spectrum which mimics
typical music and tests the thermal and mechanical capabilities of the components.
Electro-Voice will support relevant additional standards as and when they become
available. Extreme, in-house power tests,
which push the performance boundaries of
the woofers, are also performed and passed
to ensure years of trouble-free service.
Specifically, the S15 passes ANSI/EIA
RS-426-A 1980 with the following values:
R
= 5.98 ohms (1.15 x RE)
SR
= 250 watts
P
E(MAX)
Test voltage = 38.67 volts rms,
77.33 volts peak (+6dB)
The “peak” power-handling capacity of a
woofer is determined by the peak test voltage amount. For the S15, a 77.33-volt peak
test voltage translates into 1,000-watts shortterm 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.
However, this sort of short-duration peak is
very typical in speech and music. Provided
the amplifier can reproduce the signal accu-
rately, without clipping, the system will perform accurately and reliably, even at these
levels.
Amplifier Power Recommendations
As noted in the Power-Handling Capacity
section, above, the S15 has a random-noise
power capacity of 250 watts long term
(1,000 watts peak) per ANSI/EIA RS-426-A
1980. The following guidelines will help
relate this to an appropriate power amplifier
output rating.
1. To use the S15 to full capacity, skilled
experts in sound system installation and
operation will obtain the best results if
the power amplifier is 2.0 to 4.0 times
the long-term average noise power rating of the speaker system. For the S15
this is 500 to 1,000 watts.
The caution cannot be made strongly
enough, however, that this arrangement is only for experts or those who
can discipline themselves against
“pushing” the system for ever-higher
sound levels and who can avoid “accidents” such as catastrophic feedback
or dropped microphones.
2. A more conservative, “normal” amplifier
size, which will produce audible results
nearly equal to those of the “expert” recommendation, is 1.0 to 1.4 times the
long-term average noise power rating of
the speaker. For the S15 this is 250 to
350 watts.
3. To be very conservative, one can use an
amplifier rated at 0.5 to 0.7 times the
long-term average noise power rating of
the loudspeaker. For the S15 this is 125
to 175 watts.
Request P.A. Bible Addition No. Two
(“Power Handling Capacity”) for more background on these recommendations.
Service
In the unlikely event the S15 requires service, the woofer and driver can both be replaced or serviced from the front. A service
data sheet is available from Electro-Voice.
Loading...