SL12-2H
High-Output, Two-Way
Slant Cinema Surround
Speaker System
• High output—complements the
potential of digital sound sources
• 93-dB sensitivity
• 200 watts long-term power
capacity
• Easy suspension using the
optional quick-mount U-bracket
• ISO 2969 treble roll-off (switch-
able)
• Slanted profile for greater direc-
tivity
• 12-inch woofer
• 100° x 50° horn and driver
Description
The Electro-Voice SL12-2H is a 20º slanted
baffle two-way, high-efficiency speaker sys-
tem. Its primary intended application is for
high-quality surround sound in medium and
large premium cinema installations. It has
been designed for high-power digital sur-
round sound requirements using high-qual-
ity, professional-level components such as a
high-frequency 100º x 50º horn/driver and a
12-inch woofer. The sleek black-vinyl en-
closure with a black cloth grille attached with
four screws has been selected to blend into
most interior design concepts.
A second-order (12-dB-per-octave) cross-
over at 2,700 Hz is used to separate the two
frequency sections and provide equalization
for the HF driver. The bass section was de-
signed for efficient low-end performance in
a compact slant-designed enclosure.
Frequency Response
The SL12-2H 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 two re-
sponses ISO 2969 and "flat" are illustrated.
Directivity
The directional characteristics of the
SL12-2H were measured in Electro-Voice's
large anechoic chamber. The test signal was
one-third-octave filtered pink noise at the
frequencies indicated. A full spherical
measurement system was used. All direc-
tional information was measured at 20 feet.
Figure 2 illustrates the horizontal and verti-
cal polar responses.
Figure 3 shows the horizontal and vertical
beamwidths. Beamwidth is the angle at
which the horizontal and vertical polar re-
sponses have decreased in level by 6 dB
when compared with the axial frequency re-
sponse.
Figure 4 illustrates the total directivity of the
SL12-2H. The directivity factor R
θ
(Q) is the
relative value, at a point, of the SL12-2H
output when compared to an ideal spherical
response. The directivity index, D
i
, is calcu-
lated by D
i
= 10log
10
R
θ
.
Power-Handling Test
Electro-Voice components and systems are
manufactured to exacting standards, ensur-
ing 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 (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 per-
formance boundaries of the system, are also
performed and passed to ensure years of
trouble-free service.
Specifically, the SL12-2H passes EIA
RS-426-A 1980 with the following values:
R
SR
= 6.8 (1.15 x R
E
ohms
P
E(MAX)
= 200 watts
Test voltage =
36.9 volts rms.
73.8 volts peak
The "peak" power-handling capacity of a
woofer is determined by the peak test volt-
age amount. For the SL12-2H, a 73.8-volt
peak test voltage translates into an 800-watt
short-term-peak power-handling capacity.
This is the equivalent of four times the "av-
erage" 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
