Atlas AH99-8ST User manual

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] ©2008 Atlas Sound SL2-3030 ATS002871 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 also included for suspended installation
• 100 watts power handling
• Constant directivity design offers controlled coverage of 90°
horizontal by 90° vertical (2 kHz octave band)
• Driver compliment includes 8” 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 watt 70.7V transformer
• Effi ciency rating of 101 dB (1 W/1 M)
• Maximum output of 121 dB (Rated Power @ 1 M)
Applications
Atlas Sound model AH99-8ST stadium horn is ideal for directional
sound distribution where full range reproduction, maximum intelligibil-
ity, and high sound pressure levels are required. Applications include
football stadiums, sports arenas, baseball fields, convention centers, and
auditoriums.
Weather resistant construction features of the AH99-8ST include a
multiple screen configuration to prevent moisture from damaging inter-
nal 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 8” cast frame
woofer.
Installation
A heavy-duty stainless steel "C" style mounting bracket is included with
the AH99-8ST to allow easy mounting to most any flat surface. Three
drop forged 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 AH99-8ST 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.
AH99-8ST
AH99-8ST
8" AH Series Stadium Horns 90° x 90°
AH99-8ST

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] AtlasSound.com 2/4
©2008 Atlas Sound SL2-3030 ATS002871 RevA 1/08




Technical Specifications
Power Rating: 100 watts
Sensitivity 1W/1M: 101 dB SPL (70 Hz to 17 kHz 1⁄3 octave bands)
Frequency Response: 90 Hz - 15 kHz (±5 dB)
Dispersion: 90° x 90°
Impedance: 8 Ω Nominal
Transformer Taps: 7.5, 15, 30 and, 60
Height: 21.88” (555.75 mm)
Width: 19.66” (499.36 mm)
Depth: 19.73” (501.14 mm)
Shipping Weight: 102 lbs (46.27 kg)
Driver Type: 1” HF and 8” LF
Architect & Engineer Specifications
Loudspeaker shall be Atlas Sound Model AH99-8ST or approved equal.
The loudspeaker system shall be a horn-loaded, 2-way design with an 8”
inch polycone woofer.
The loudspeaker system shall include an 8”, 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
(18 dB/octave) dividing network shall have a crossover frequency of 1.8
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 100 watts RMS based on EIA Standard RS-426B.*
Enclosure shall be UV-resistant, low pressure injection molded fiberglass
and shall include a 3 stage multiple mesh filter system for weather and
rodent resistance: to include a 20-gauge perforated aluminum screen on
front mouth assembly, a 100 x 100 weave stainless steel mesh between
HF horn and HF driver and a 100 x 100 weave stainless steel mesh over
8” woofer. The loudspeaker shall include a stamped and formed, 2 mm
stainless steel powder coated mounting bracket assembly for surface
mounting and three 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 100 dB SPL (90 Hz – 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 90 Hz – 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 70.7V transformer with 7.5, 15, 30, & 60
watts taps and a bypass 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: 21.88” (555.75 mm)
Width: 19.66” (499.36 mm)
Depth: 19.73” (501.14 mm)
Weight: 102 lbs (46.27 kg)
* EIA test spectrum is applied for eight hours.
(This procedure provides a rigorous test of both thermal and
mechanical failure modes.)
19.73"
(501.14 mm)
12.03"
(305.56 mm)
21.88"
(555.75 mm)
19.66"
(499.36 mm)

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] AtlasSound.com 3/4
©2008 Atlas Sound SL2-3030 ATS002871 RevA 1/08
AH99-8ST Horizontal Beamwidth (- 6dB)
AH99-8ST Vertical Beamwidth ( -6 dB)
AH99-8ST Frequency Response

1601 JACK MCKAY BLVD. ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: [phone]
FAX [phone] AtlasSound.com 4/4
©2008 Atlas Sound SL2-3030 ATS002871 RevA 1/08
AH99-8ST Impedance (ohms) vs. Frequency
AH99-8ST Polars (Normalized To Zero On Axis) ( -6 dB)
AH99-8ST Polars (Normalized To Zero On Axis) ( -6 dB)