Atlas AH99-12ST User manual

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] ©2008 Atlas Sound SL2-3036 ATS002873 RevA 1/08 AtlasSound.com 1/4
Features
• Heavy duty mounting bracket (included) allows for easy installation to
most any fl at surface
• Three forged eyebolts included for suspended installation
• 200 watts power handling
• Constant Directivity design offers controlled coverage of 90°
horizontal by 90° vertical (2 kHz octave band)
• Driver compliment includes 12” cast frame woofer with a
concentrically mounted 1” exit compression driver coupled to a 90°
H x 90° V HF horn
• Easy, weather resistant connection via a convenient recessed
terminal block located on the bottom of the loudspeaker
• Includes a built-in, high effi ciency 60 watts 70.7V transformer
• Effi ciency rating of 101 dB (1 W/1 M)
• Maximum output of 126 dB (Rated Power @ 1 M)
Applications
Atlas Sound model AH99-12ST stadium horn is ideal for directional
sound distribution where full range reproduction, maximum intelligibility,
and high sound pressure levels are required. Applications include football
stadiums, sports arenas, baseball fields, convention centers, and audito-
riums.
Weather resistant construction features of the AH99-12ST include a mul-
tiple screen configuration to prevent moisture from damaging internal
components.
A perforated aluminum screen covers the large horn mouth, a secondary
screen is in place forward of the high frequency driver, and a third tightly
perforated screen protects the 12" cast frame woofer.
Installation
A heavy-duty stainless steel "C" style mounting bracket is included with
the AH99-12ST to allow easy mounting to most any flat surface. Three
drop forge eyebolts are also pre-installed (2-front of horn plus 1-rear for
"pull-up") for suspension mounting via load rated wire rope. (Use caution
when suspending any object overhead. Refer to installation manual for
more details).
The AH948-ST includes a weather resistant 7 pole terminal block con-
nector on the underside of the speaker for ease of hook-up. This ter-
minal block includes connection points for internal 70.7V transformer
with taps settings of 7.5, 15, 30, and 60 watts and 8 Ω connection for
transformer bypass.
AH99-12ST
AH99-12ST
12" AH Series Stadium Horns 90° x 90°
AH99-12ST

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] AtlasSound.com 2/4
©2008 Atlas Sound SL2-3036 ATS002873 RevA 1/08
Technical Specifications
Power Rating: 200 watts
Sensitivity 1 W / 1 M: 101 dB SPL (70 Hz to 17 kHz 1⁄3 octave bands)
Frequency Response: 80 Hz - 15 kHz (±5 dB)
Dispersion: 90° x 90°
Impedance: 8 Ω Nominal
Transformer Taps: 7.5, 15, 30, & 60 watts
Height: 25.68” (652.27 mm)
Width: 22.06” (560.32 mm)
Depth: 22.57” (573.28 mm)
Shipping Weight: 136 lbs (61.69 kg)
Driver Type: 1” HF and 12” LF
Architect & Engineer Specifications
Loudspeaker shall be Atlas Sound Model AH99-12ST or approved equal.
The loudspeaker system shall be a horn-loaded, 2-way design with a 12
inch paper cone and moisture resistant coating.
The loudspeaker system shall include a 12”, horn loaded, cast frame
woofer and an integral, concentrically mounted 1” exit compression driv-
er coupled to a constant directivity high frequency horn. The three pole
(18dB/octave) dividing network shall have a crossover frequency of 1.6
kHz. The dividing network shall include a poly switch protection circuit
for the high-frequency component.
The loudspeaker system shall be capable of providing a sound dispersion
angle of 90˚ horizontal by 90˚ vertical in the 2 kHz octave band.
Rated power shall be 200 watts RMS based on EIA Standard RS-426B.*
Enclosure shall be UV-resistant, steel reinforced, low pressure injection
molded fiberglass and shall include a 3 stage multiple mesh filter system
for weather and rodent resistance: to include a 20GA perforated alumi-
num screen on front mouth assembly, a 100x100 weave stainless steel
mesh between HF horn and HF driver and a 100x100 weave stainless
steel mesh over 12” woofer. The loudspeaker shall include a stamped
and formed, 2 mm stainless steel powder coated mounting bracket
assembly for surface mounting and (3) M8 drop forged eyebolts for
suspension mounting two at the front and one at the rear to allow the
speaker system to be suspended and aimed using rated wire rope.
Sensitivity shall be 101 dB SPL (80 Hz to 15 kHz in 1⁄3 octave bands)
measured at a distance of one meter on axis with a one watt input half
space (2.83V).
Overall frequency response shall be 80 Hz to 15 kHz (±5 dB).
The input section located on the bottom rear of the loudspeaker shall be
via 7 position screw down terminal strip internally configured to allow
input to an internally mounted 70.7 V transformer with 7.5, 15, 30, & 60
watts taps and a by-pass jumper direct coupled to the speaker for nomi-
nal 8 Ω operation. The system connections shall be protected from the
elements by a screw affixed weather resistant cover.
Dimensions shall be: Height: 25.68” (652.27 mm)
Width: 22.06” (560.32 mm)
Depth: 22.57” (573.28 mm)
Weight: 136 lbs (61.69 kg)
* EIA test spectrum is applied for eight hours.
(This procedure provides a rigorous test of both thermal and
mechanical failure modes.)
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22.57"
(573.28 mm)
14.65"
(372.11 mm)
25.68"
(652.27 mm)

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] AtlasSound.com 3/4
©2008 Atlas Sound SL2-3036 ATS002873 RevA 1/08
AH99-12ST Horizontal Beamwidth ( -6 dB)
AH99-12ST Vertical Beamwidth ( -6 dB)
AH99-12ST Frequency Response

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] AtlasSound.com 4/4
©2008 Atlas Sound SL2-3036 ATS002873 RevA 1/08
AH99-12ST Impedance (ohms) vs. Frequency
AH99-12ST Horizontal Polars (Normalized To Zero On Axis) ( -6 dB)
AH99-12ST Vertical Polars (Normalized To Zero On Axis) ( -6 dB)