Sound Masking Products

ASM1317C Pendant Masker
 
Features
  • Eight inch diameter, dual-cone loudspeaker
  • 1/4, 1/2, 1, 2, 4 Watt Taps
  • 70.7 Volt Transformer


General Applications
The ASM1317C is designed for high visual applications that require architectural appeal in facilities that do not have ceiling plenums. When installed, the assembly is visible and sound distribution within the area is very uniform. It may be used for any application where superior sound uniformity is required, such as masking sound, paging and music systems or where the speaker assembly will not be concealed.

General Description of Operation
The ASM1317C contains an eight inch diameter loudspeaker with a dual cone to handle masking, music and paging signals. The unit has a multi-tap 70.7 Volt transformer with 1/4, 1/2, 1, 2, and 4 Watt taps so each loudspeaker can be individually adjusted. The transformer is factory installed. It has a 3/8" cable connector with wire leads protruding for easy cable connection and strain relief.

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ASM2410 Window Masker
 
Features
  • Lightweight and easy to install
  • Compact and small
  • Easily removable
  • Generates both sound and vibration
  • Can be driven with standard masking equipment
  • Can be retrofitted to any window
  • Does not require a separate transformer


General Applications
The ASM2410 Window Masker is used to create sound and vibration at windows for the purpose of Audio Security. When properly placed and equalized, these Maskers will protect against acoustical listening devices and vibration detection devices, such as laser microphones. They may be used on all types of windows.

General Description of Operation
The ASM2410 is a thin, 2 5/8 inch diameter piezoelectric material that is caused to vibrate by applied fluctuating voltage. This material is mounted in a specially designed housing that permits the device to transmit vibration to the window on which it is mounted, and to make sound directly. The vibration of the window creates a sound field outside the window effectively blocking the ability to listen from that side. The vibration caused by the masker covers the vibration induced in the window by persons talking within the room, thus blocking the ability for vibration listening devices to pick up meaningful conversation.

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ASM2420 Door Masker
 
Features
  • Lightweight and easy to install on door
  • Has removable cover for inspection
  • Cover minimizes build-up of background sound
  • Generates both sound and vibration
  • Causes masking to be generated in door cracks
  • Equivalent to a 10 point increase in STC
  • Does not permanently damage door
  • Can be driven with standard masking equipment
  • Can be retrofitted to most any door


General Applications

The ASM2420 Door Masker is used to create sound at the perimeter of the room. Usually it is used to increase Speech Privacy in the office environment, although it can be used to make music or paging. In most cases, the door to an office is the weakest link in providing audio security. The standard approach has been to buy an expensive, high STC door with a drop sill. The ASM2420 effectively increases the STC of the wall system into which the door fits and eliminates the need for expensive, high performance, acoustical doors.

General Description of Operation
The ASM2420 is a thin, 2 5/8 inch diameter piezoelectric material, that is caused to vibrate by applied fluctuating voltage. This material is mounted in a specially designed housing that permits the device to transmit vibration to the door on which it is mounted and to make sound directly. The vibration of the door radiates outward from the transducer and in turn makes the door itself into a low level loudspeaker. A six inch square cover, with a fiberglass fill, goes over the transducer. Since for security purposes the Masker must be mounted within the room, this cover acts to reduce the sound produced in that room. It also protects the device and adds aesthetic appearance.

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ASM2430 Wall Masker
Features
  • Puts sound inside wall cavity, not on wall
  • Lightweight and easy to install
  • Easily removed for inspection
  • Generates low sound levels inside room
  • Can be driven with standard masking equipment
  • Can be installed in walls with at least 3 5/8 inch stud
  • Wide range of individual level adjustment
  • Does not require a separate transformer

General Applications
The ASM2430 Wall Masker is used to create audio security at the perimeter of a secure room through generation of low level masking sound within wall cavities. When properly installed it protects against listening devices within the wall, listening devices outside the wall, and persons listening at or near the wall. When controlled by the ASM1020 Security Generator, it also protects against someone using sophisticated signal processing techniques that could recover the speech that may be buried in the masking.
The standard method of providing audio security in a secure room is to use an STC-45 wall. Such walls are expensive, may not be adequate (nor can they be adjusted to be adequate), and are not protection against all forms of listening. The advantage of masking sound within the wall is that standard wall construction is adequate, results can be guaranteed, and there is protection against in-wall listening With proper signal generating equipment the masking can also protect against signal processing techniques.


General Description of Operation
The ASM2430 is a cylindrical tube that penetrates into the wall cavity from the secure side. The tube contains a loudspeaker and a transformer to create sound within the cavity. The tube has a flat plate on the end toward the secure room. This plate screws to a collar that is permanently secured to the wall; the unit may be removed, inspected, or replaced merely by unscrewing the plate. Wires protrude from the unit. By proper choice of wire pair, it is possible to obtain a wide range of sound levels at any unit.

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ASM2440 Rectangular Duct Masker
Features
  • Puts sound inside rectangular ducts
  • Lightweight and easy to install
  • Easily removed for inspection
  • Generates high sound levels inside duct
  • Does not cause pressure drop in the air flow
  • Can be driven with standard masking equipment
  • Meets criterion for duct masking
  • Wide range of individual level adjustment
  • Does not require a separate transformer

General Applications
The ASM2440 Rectangular Duct Masker is used to increase speech privacy in areas that do not have a normal sized plenum with a suspended ceiling. The unit may be attached to the air duct and the masking sound is transmitted to the room via the ducts. It also may be used as a plenum loudspeaker in rooms with a ceiling plenum smaller than 12 inches. It may also be used in rooms that have a high structural ceiling but no suspended ceiling. The masker may be placed on top of exposed air conditioning ducts, beams, etc.

The ASM2440 Rectangular Duct Masker may be used to create audio security within rectangular ducts that penetrate the perimeter of a secure room through generation of masking sound within the duct. The duct must have a flat surface of at least nine inches square. When properly installed it protects against listening devices within, on, or near the duct on the unsecured side. When controlled by the ASM102 Series Security Generators, it also protects against someone using sophisticated signal processing techniques that could recover the speech that may be buried in the masking.

The standard method of providing audio security in a secure room is to use a muffler. Such devices are heavy, costly to purchase and install, may be large, and generally have long procurement lead times. To keep vibration from being transmitted from the muffler frame to the duct that penetrates the perimeter, they often use canvas, or other flexible, connectors. Such connectors do not block sound transmitted directly from the room below, through the ceiling and through the connector; as a result, the muffler performance is most often compromised. As with all loss elements, they cannot take into account the background sound level at the listening position, so guarantees of audio security cannot be made. Instead, the addition of masking sound, of the proper level, directly into an unmodified duct can guarantee audio security at considerable cost savings.

General Description of Operation
The ASM2440 is a completely assembled masking loudspeaker that is ready for installation. The mounting surface of the unit is 9 inches square. It is 4 1/2 inches deep. It contains an 8 inch diameter speaker with a dual cone. It has a 70.7 volt transformer with 1/4, 1/2, 1, 2, and 4 watt taps. The unit has an external rotary switch so the tap settings may be changed without rewiring. The speaker is covered with a mesh grille and a impervious plastic sheet to protect the speaker from duct static air pressure and to prevent air leakage. The unit is external to the duct so no pressure drop is caused by installation.

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ASM2450 Circular Duct Masker
Features
  • Puts sound inside circular ducts
  • Lightweight and easy to instal
  • Easily removed for inspection
  • Generates high sound levels inside duct
  • Does not cause pressure drop in the air flow
  • Can be driven with standard masking equipment
  • Meets criterion for duct masking
  • Wide range of individual level adjustment
  • Does not require a separate transformer

General Applications
The ASM2450 Circular Duct Masker is used to create audio security within circular ducts, or rectangular ducts less than 9 inches, that penetrate the perimeter of a secure room through generation of masking sound within the duct. The unit may be installed on metal or fiberglass ducts. When properly installed it protects against listening devices within, on, or near the duct on the unsecured side, and against persons listening at or near the duct. When controlled by the ASM102 Security Generator, it also protects against someone using sophisticated signal processing techniques that could recover the speech that may be buried in the masking.

The standard method of providing audio security in a secure room is to use a muffler. Such devices are heavy, costly to purchase and install, may be large, and generally have long procurement lead times. To keep vibration from being transmitted from the muffler frames to the ducts that penetrates the perimeter, they often have canvas, or other flexible, connectors. Such connectors have low loss for sound transmitted directly from the room below, through the ceiling and through the connector; as a result, the muffler performance is most often compromised. As with all loss elements, they cannot take into account the background sound level at the listening position, so guarantees of audio security cannot be made. Instead, the addition of masking sound of proper level directly into an unmodified duct can guarantee audio security at considerable cost savings. With proper signal generating equipment the masking can also protect against signal processing techniques.

General Description of Operation
The ASM2450 is a square plate, 4 inches on a side, with two tabs on one side that are bent at right angles, each in opposite directions. Each tab has two holes for attaching the unit to the duct with sheet metal screws. In the center of the plate is a 2 1/2 inch diameter hole that is covered with a piezoelectric transducer. This transducer is the sound source, and has two wires that lead to the junction between the two tabs.

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ASM2460 Plenum Masker
Features
  • Eight inch diameter
  • Dual cone loudspeaker
  • 1/4, 1/2, 1, 2, 4 Watt taps
  • 575 cubic inch cylindrical enclosure
  • 70.7 Volt transformer
  • Exterior rotary switch for tap setting

General Applications
The ASM2460 is designed for easy and rapid installation into the ceiling plenum of secure areas with suspended ceilings, so installation labor costs are reduced. When installed, the unit is invisible, no ceiling penetrations are required, and sound distribution below the ceiling is very uniform. It may be used for any application where superior sound uniformity is required, such as within SCIF areas or near doors. It may be hung vertically upward, vertically downward or horizontally.

General Description of Operation
The ASM2460 contains an eight (8) inch diameter loudspeaker with a dual cone. The unit has a multi-tap 70.7 Volt transformer with 1/4, 1/2, 1, 2, and 4 Watt taps so each loudspeaker can be individually adjusted within a range of 12 dB. The transformer is factory installed with an off position. The ASM2460 has a rotary switch on the exterior to make the tap settings easily changeable. The unit enclosure has 575 cubic inches volume, a hanging bracket, and a 3/8" cable connection as an outlet for the wires.

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ASM2470 Pipe Masker
Features
  • Puts sound on and inside pipes
  • Handles 1/2 inch conduit to 8 inch pipes
  • Lightweight and easy to install
  • Easily removed for inspection
  • Generates high sound levels inside pipe
  • Does not affect pipe use

General Applications
The ASM2470 Pipe Masker is used in applications where there is concern that pipes penetrating a secure area may transmit meaningful speech sounds. Such pipes may be refrigerant lines, Halon lines, electrical conduit, water pipes, etc.

General Description of Operation
The ASM2470 is a completely assembled vibration masker that is ready for installation. The transducer is a thin, 2 5/8 inch diameter piezoelectric material that is caused to vibrate by applied fluctuating voltage. This material is mounted in a specially designed housing that permits the device to transmit vibration to the masker frame, which is mounted on the pipe. The vibration of the frame creates a vibration field within the pipe structure, which in turn causes a sound field within the pipe. Thus the masker covers both vibrations detection methods as well as sound measurements within the pipe. When controlled by the ASM102 Series Security Generators, it also protects against someone using sophisticated signal processing techniques that could recover the speech that may be buried in the masking.

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ASM2480 Loudspeaker Masker
Features
  • Puts masking sound into loudspeakers or horns
  • Does not interfere with loudspeaker operation
  • Lightweight and easy to install
  • Easily inspected
  • Can be driven with standard masking equipment
  • Does not require a separate transformer

General Applications
The ASM2480 Loudspeaker Masker is used to create audio security within rooms that are required to have loudspeakers driven from locations outside the secure area. Typical situations of this type are emergency evacuation horns or emergency paging speakers in either owned or leased space.

Since loudspeakers can function as microphones, the presence of these speakers within a secure room permits the possibility of audio surveillance. When conversations are held in the room, the sound pressure of the speech causes the loudspeaker diaphragm to move slightly. This results in a small voltage fluctuation in the speaker wire, which can be detected outside the secure area and resolved into speech. The ASM2480 Loudspeaker Masker is placed directly above, and emits masking sound directly into the speaker and is set at sufficient level to mask all conversations. It is a lightweight unit that is attached easily to the horn or speaker. Since the unit is small, it does not interfere with the normal functioning of the speaker.

The ASM2480 Loudspeaker Masker may also be used to provide audio security in secure rooms that have small openings to other rooms. This opening may be for return air, but it may also be for document passing. Such openings are not recommended, as the level of the masking sound must be relatively high in order to assure audio security.

When controlled by the ASM102 Series Security Generators, the ASM2480 also protects against someone using sophisticated signal processing techniques that could recover the speech that may be buried in the masking.

General Description of Operation
The ASM2480 is a square plate, 4 inches on a side, with one tab on one side that can be bent to accommodate the geometry of the speaker, horn, or surface to which it is attached. The tab has two holes for sheet metal or machine screws so the unit can be attached to the speaker. In the center of the plate is a 2 5/8 inch diameter piezoelectric transducer. This transducer is the sound source, and has two wires that lead to the junction and should be attached to a power amplifier with a nominal 70 Volt audio line such as the ASM160 Series Zone Power Amplifiers.

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ASM2490LP Low-Profile Access Floor Masker
Features
  • Loudspeaker
  • Rotary switch
  • Enclosure
  • Transformer
  • Cable connector

General Applications
The ASM2490LP (Low Profile) is designed for easy and rapid installation into access floor cavities, generally less than 5 inches in height, so that sound masking signals can be disburse both effectively and efficiently in such a confined space. When installed, the assembly is invisible, no floor penetrations are required, and sound distribution within the access floor cavity is very uniform. It is used for applications where superior sound uniformity is required and conventional ceiling plenum masking is not appropriate. It is positioned on the floor of the access floor cavity with the perforations facing upward.

General Description of Operation
The ASM2490LP is uniquely fabricated for use with low-profile access floors less than six inches in height. The unit has a multi-tap transformer with a factory installed rotary switch so each loudspeaker can be individually adjusted. The unit has a cable connector mounted on the enclosure with wire leads protruding for easy cable connection and strain relief.

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ASM2490LPC Low-Profile Ceiling Masker
Features
  • Four inch diameter loudspeaker
  • 1/4, 1/2, 1, 2, and 4 Watt taps
  • Nominal 5 ¼” x 6 ¼” x 1 7/8” high
  • Black metallic enclosure
  • 70.7 Volt transformer
  • Exterior rotary switch for tap setting
  • Single-point suspension

General Applications
The ASM2490LPC is designed for easy and rapid installation into the ceiling plenum of offices with shallow, suspended ceilings, so installation labor costs are reduced. When installed, the assembly is invisible, no ceiling penetrations are required, and sound distribution below the ceiling is very uniform. It may be used for any application where superior sound uniformity is required – in ceiling plenums less than 30” high.

General Description of Operation
The ASM2490LPC contains a four (4) inch diameter loudspeaker. The unit has a multi-tap 70.7 Volt transformer with on and off 1/4, 1/2, 1, 2, and 4 Watt taps so each loudspeaker can be individually adjusted. The transformer is factory installed. The ASM2490LPC has a rotary switch on the exterior to make the tap settings easily changeable. The unit has an eyelet for easy suspension. Additionally it has a 3/8" cable connector mounted on the enclosure for cable termination.

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