S12
Two-Way Stage Speaker
System
• PRO
TM
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
®
inputs
1
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1
See Connections section
Description
The Electro-Voice S12 is a 250-watt, two-
way, high-efficiency, constant directivity
stage system featuring a vented, direct-radi-
ating woofer section. It combines profes-
sional quality Electro-Voice components in
an unusually durable, light-weight enclosure.
The result is wide-range accurate sound re-
production with transparent highs and ex-
tended bass response.
The high-frequency section of the S12 uti-
lizes 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
TM
phasing plug structure (U.S. Patent
#4,525,604) for smooth and extended high-
frequency performance. The voice coil is
coupled to the diaphragm with EV’s exclu-
sive Resonant Drive
TM
Technology. This in-
creases and smooths the high-frequency re-
sponse and reduces the amount of internal
equalization required for flat frequency re-
sponse. Driver output extends to 20,000 Hz.
A self-resetting high-frequency protection
circuit, EV’s PRO
TM
circuit, is included with
the S12 to prevent against accidental over-
drive and improve system reliability. If the
input power to the high-frequency driver
exceeds the nominal rating, the protection
circuit is activated and reduces the power de-
livered 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 S12 is designed us-
ing Thiele-Small parameters for solid per-
formance to 53 Hz. The 305-mm (12-in.)
SG12 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 du-
rable Thiele-Small-aligned vented enclosure.
The result is clear and articulate, high-qual-
ity sound.
Speaker Protection
The S12, like all other vented systems, ex-
periences rapidly increasing cone excursion
below the box-tuning frequency, while the
acoustic output decreases rapidly. Therefore,
to protect the S12 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 S12 enclosure is constructed of Road-
Wood
TM
, a structural material that combines
the strength of high-quality plywood with the
density and acoustic damping of particle
board without brittleness. Road-Wood
TM
uses the same principle of crossbanding ve-
neers, 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 perpen-
dicularly bonded under intense heat and pres-
sure to form panels of superior uniformity.
Unlike many grades of plywood, Road-
Wood
TM
is dimensionally stable, water-resis-
tant 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, abuse-
resistant carpeting provides a finish that is
both attractive and highly durable. Heavy-
duty metal corner protectors, firmly secured
rubber feet, recessed handles and a protec-
tive metal grille complete the picture and
