Atlas IED GD87 User Manual
Specifications subject to change without notice
© 2003 Atlas Sound Printed in U.S.A. 00203 ATS001453 RevB 2/03 SL1-2024
2.45
One
1601 JACK MCKAY BLVD. / ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: (800) 876-3333 / FAX (800) 765-3435
AtlasSound.com
FEATURES
• Industry standard 8" (203mm) coaxial, 16 watt, loudspeaker with
high quality factory installed 8 watt line matching transformer
• Offers proven performance with wide frequency response
• Post-mounted tweeter adds strength and a more
attractive appearance
• Ideal for multi-purpose commercial, industrial and institutional use
• Individually packaged for stocking & ordering convenience
APPLICATIONS
Use Atlas Sound 8" (203mm) diameter, multi-purpose, coaxial loudspeaker Model GD87 for voice transmission, music and signal
reproduction in high-quality commercial, industrial and
institutional applications.
GENERAL DESCRIPTION
The speaker used in the GD87 is the next generation of Atlas high
performance cone loudspeakers, very similar to the preceding
C-Series speakers. The similarity in the sonic qualities ensures that
contractors and designers who have worked with the Atlas Sound
C803A Series in the past will know exactly what to expect when they
use the GD87.
The high-quality, 25 watt Model GD87 utilizes a post mounted tweeter
which adds strength to the assembly and provides an attractive appearance. This coaxial loudspeaker features a 45Hz-19kHz (nominal)
frequency response and a broad, uniform dispersion pattern of 90° @
2kHz. Such provisions allow for highly intelligible sound reproduction
and better distribution for high-quality sound systems. The GD87 combines a full-size 8" (203mm) dia., low-frequency reproducer and a 3"
(76mm) high-frequency reproducer. The two sections are coupled via a
built-in crossover network. The woofer has a 10oz. (260g) ceramic
magnet; the tweeter has a 2.35 oz. (67g) ceramic magnet. The unit has
an average sensitivity of 96dB (1W/1M). The loudspeaker is matched
with a high efficiency 8 watt 70.7V transformer with a maximum insertion loss of 0.6dB. This premium transformer is constructed of audio
grade laminations and has a full range frequency response of +1dB
from 50Hz to 15kHz. The primary taps are 1, 2, 4, and 8 watts.
ARCHITECT & ENGINEER SPECIFICATIONS
Unit shall be Atlas Sound 8" diameter. loudspeaker/transformer
combination Model GD87. The low-frequency reproducer cone shall be
a full 8" (203mm) in diameter and the high frequency reproducer cone
shall be 3" (76mm) in diameter. The woofer shall have a 10oz. (260g)
ceramic magnet; the tweeter shall have a 2.35oz. (67g) ceramic magnet. The two reproducer sections shall be coupled through a built-in
crossover network. The crossover frequency shall be at 2800Hz.
Frequency response range shall be 100Hz-10kHz (nominal). Average
sensitivity shall be 97dB (1W/1M). Low frequency voice coil diameter
shall be 1" (25mm) and operate in a magnet field of at least 10,600
gauss. Transformer primary voltage shall be 70.7V with a frequency
response range of ±1dB-50Hz-15kHz and power taps at 1,2,4 & 8
watts. Insertion loss shall not exceed .6dB. The maximum depth of the
loudspeaker/transformer package shall not exceed 2.875" (73mm).
8" COAXIAL SPEAKER/TRANSFORMER ASSEMBLY
GD87
GD87 SPECIFICATIONS
Size 8"(205mm)
Power Handling 25 Watts Peak, 15 Watts RMS
Sensitivity 96dB Average
Impedance 8 Ohms Nominal
Frequency Response 45Hz-19kHz Nominal, 55Hz-15kHz ±5dB
Dispersion 105° (2kHz Octave Band, -6dB Points)
Diameter & Depth 8.125"(205mm) Dia. & 2.875"(73mm) Deep
Mounting Dimensions 7.625"(194mm) Bolt Circle
Cone Material Treated Paper
Surround Material & Damping Damped Self Edge
Flux Density 10,600 Gauss, 1.06 Tesla
Magnet Weight Nominal, 10oz. (260g)
Basket Material Stamped Plated 20ga. CRS
VC Diameter 1"(25mm)
VC Material Copper
VC Former Material Black Anodized Aluminum
VC Winding Width .225
"
Top Plate Thickness .239
"
Weight 32oz. (908g)
THIELE-SMALL PARAMETERS
Pe 15 watts
Fs 125Hz
Xmax .05
"
Resistance 7.3 Ohms
Qts 0.8
Qes 0.95
Qms 5.2
BL 7.9 N/A
Efficiency 1.90%
Vas .32 (ft3)
Sd 33.2 (in2)
Le@1kHz .36 mH
Mms .39oz.
Cms .024 in./lb.
Transformer Specifications
Frequency Response 50Hz-15kHz (±1dB)
Primary Taps (Watts) 1, 2, 4 & 8
Secondary Impedance (ohms) 4 & 8
Maximum Insertion Loss .6dB
Primary Termination 6" (152mm) Com. Lead Color Coded
Core Size 1
" x 3⁄4"
(25 X 19mm)
Power Rating (Watts) 8
GD87
(Front View) (Rear View)
Fundamental
Fundamental vs. 2nd & 3rd Harmonics
(Transformer Bypassed)
GD87 Frequency Response
(Transformer Bypassed)
GD87 Impedance
(Transformer Bypassed)
Frequency Hz
Frequency Hz
dB Pa
Ohms
dB Pa
Frequency Hz
2nd Harmonic
3rd Harmonic
GD87 OCTAVE BAND POLARS
Specifications subject to change without notice
© 2003 Atlas Sound Printed in U.S.A. 00203 ATS001453 RevB 2/03 SL1-2024
1601 JACK MCKAY BLVD. / ENNIS, TEXAS 75119 U.S.A.
TELEPHONE: (800) 876-3333 / FAX (800) 765-3435
AtlasSound.com
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