
EXPLOSION-PROOF LOUDSPEAKERS
HLE-1 Driver
HLE-1 Driver mounted to HLE/MLE-30 Horn 
(order separately)
60 AND 30 WATT
HLE/MLE Series
FEATURES
• Explosion-Proof Loudspeakers for Signal and Communications Systems
• Listed by UL and CSA for Use in Hazardous/Combustible Environments (noted models)
• Available with Internally Mounted, Factory-Installed Transformer
• Choice of 60 or 30 Watt High-Intelligibility Driver in Cast Aluminum Housing
• Efficiency of Reflex-Style Projectors with Wide Angle or Circular Sound Dispersion
APPLICATIONS
Install HLE or MLE Series loudspeakers to efficiently and safely communicate in combustible 
and dust-filled areas. All drivers comply with the regulations governing electrical equipment at 
hazardous locations as set forth by the National Electric Code. Drivers are listed by UL and 
CSA (HLE Series only). They are recommended for paging, signal and voice communication in 
chemical processing, petroleum, natural resource exploration and atmospheres as listed in the 
chart below.
GENERAL DESCRIPTION
Series HLE and MLE loudspeakers are explosion-proof compression driver/horn assemblies  
engineered for high-efficiency voice and electronic signal communication in hazardous areas.  
Drivers, which are protected within a rugged die-cast aluminum housing, are available in 
60-watt (HLE Series) and 30-watt (MLE Series) power handling versions. Models with T suf 
fix include a factory-installed, internally mounted transformer (Note: To meet UL requirements 
transformer must be factory installed). All models are equipped with 
adjustable mounting bracket. 
1
⁄2" conduit access and an 
-
TWO
Projector horns are available in two styles to meet dispersion requirements. Model HLE/MLE30 is a high-quality, polycarbonate projector that creates a 120 ° x 60 ° pattern for wide area 
coverage. Model HLE/MLE-32 is a spun aluminum bell providing a 95 ° circular distribution 
emphasis.
Note: – For Canadian use (Price List page 17 Text)
HLE-1 Driver mounted to HLE/MLE-32 
Horn (order separately)
Drivers and projector horns are ordered and shipped separately. For performance accuracy, 
specifications are listed for assembled configurations. 
   MODEL   POWER  FREQ.  SOUND        INTERNAL  ASSEMBLY
 DRIVER   HORN  RATING RESPONSE LEVEL* SENSITIVITY** DISPERSION IMPEDANCE  XFMR   SIZE 
 HLE-1(T)  HLE/MLE-30 60 Watts  250 Hz-  109dB  -18dBm  120 ° x 60 °  16 Ohms  60 Watt  Driver & Horn 
 HLE-3(T)  HLE/MLE-30  Cont.  12 kHz  108dB        Model T-18  
 MLE-1(T)  HLE/MLE-30 30 Watts  300 Hz  107dB  -21dBm  120 ° x 60 °  8 Ohms  30 Watt  (35.6 x 15.2 x  
 MLE-3(T)  HLE/MLE-30  Cont.  14 kHz  106dB        Model T-20  44.5cm) 
 HLE-1(T)  HLE/MLE-32 60 Watts  190 Hz-  112dB  -16dBm  95 °  16 Ohms  60 Watt  Driver & Horn 
 HLE-3(T)  HLE/MLE-32  Cont.  12 kHz  111dB        Model T-18  161⁄2"Dia. x 
 MLE-1(T)  HLE/MLE-32 30 Watts  200 Hz-  110dB  -20dBm  95 °  8 Ohms  30 Watt  (42 x 54.6cm) 
 MLE-3(T)  HLE/MLE-32  Cont.  10 kHz  110dB        Model T-20
  *  Measured 1 Watt / 1 Meter. 
 **  As microphone; re 10  dynes / cm2
 DRIVER  CLASS / GROUP  FOR ATMOSPHERE CONTAINING: 
 HLE-1(T)  Class 1 / Division 1 / Group C & D  Gas Atmospheres (Including Ethyl, Ether, Gasoline Naphtha, Alcohols) 
 MLE-1(T) 
 HLE-3(T)  Class 1 / Division 1 / Group B, C & D  Gas Atmospheres (Including Ethyl, Ether, Gasoline Naphtha, Alcohols, 
 MLE-3(T)    Butane, Propane) plus, Hydrogen, Gas and Vapor, (Manufactured Gas)
UNDERWRITERS' LABORATORY LISTINGS
(“T” versions only)
14"W x 6"H x 171⁄2”D
Specifications subject to change without notice
1601 JACK MCKAY BLVD. / ENNIS, TEXAS 75119 U.S.A. 
TELEPHONE: (800) 876-3333 / FAX (800) 765-3435
 © 2007 Atlas Sound  Printed in U.S.A.  000202  SL2-1421
AtlasSound.com
167

ARCHITECT AND ENGINEER SPECIFICATIONS
Explosion proof loudspeaker shall be UL Listed for use in specified 
hazardous locations and/or combustible atmospheres as classified by 
the National Electric Code. 
UL approved compression driver for 60 Watt distributed application 
shall be Atlas Sound Model HLE-1T or HLE-3T with internally mounted 
60-watt transformer Model T-18. Transformer shall have primary 
impedance taps at 2000, 1000, 500, 250, 125 and 85 with a 45 Ohm 
tap for 45 Ohm line use only. Corresponding power taps for 70.7V line 
use shall be 2.5, 5, 10, 20, 40 and 60. Secondary impedance shall be 
4, 8 and 16 Ohms. For voice-coil circuit applications, UL Listed 60 Watt 
Model HLE-1, or HLE-3 with 16 Ohm voice coil shall be specified.
UL approved compression driver for 30-watt distributed application 
shall be Atlas Sound Model MLE-1T or MLE-3T with internally mounted 
30 Watt transformer Model T-20. Transformer shall have primary 
impedance taps at 2500, 1300, 666, 333, 167, 89 and 45 Ohms. 
Corresponding power taps for 70.7V line use shall be 1.8, 3.7, 7.5, 15, 
and 30. Power taps for 25V line shall be 1.89, 3.7, 7, and 15. Secondary 
impedance shall be 8 Ohms. For voice-coil circuit applications, UL 
Listed 30 Watt Model MLE-1, or MLE-3 with 8 Ohm voice coil shall be 
specified. 
Driver and transformer, where applicable, shall be mounted within a 
heavy, cast aluminum housing. Voice coils shall be field-replaceable.  
Projector horn shall be a reflex type with polycarbonate re-entrant 
section. It shall be Atlas Sound Model HLE/MLE-30 for 120 
dispersion or HLE/MLE-32 for 95˚ sound coverage. Driver and horn 
assembly shall have a frequency response of _______ with sensitivity 
of _______(measured at 10 dynes / cm 
be a minimum of ________(measured at 1W/1M).
2
). Sound pressure level shall 
˚
 x 60˚ sound 
Specifications subject to change without notice
1601 JACK MCKAY BLVD. / ENNIS, TEXAS 75119 U.S.A. 
TELEPHONE: (800) 876-3333 / FAX (800) 765-3435
 © 2007 Atlas Sound  Printed in U.S.A.  000202  SL2-1421
AtlasSound.com