The ANG-2200 Acoustic Noise Generator is designed to create a perimeter of noise around a target area that defeats wired microphones inside walls, contact microphones, audio transmitters located in AC outlets, and laser/microwave reflections from windows.
Most sound masking systems inject noise into an otherwise benign environment. In this environment, the occupants must raise their voices above the noise level to communicate, which invariably, eliminates the benefit of noise masking. The PNG-200 masking system injects noise into the environment perimeter and not directly into the environment. This approach allows normal conversation while defeating eavesdropping devices that rely on acoustic leakage.
Sound vibrates surfaces such as walls, glass, and doors. A contact microphone can pickup these vibrations and transmit the information along wires or modulate it onto radio waves to be received by an unwanted listener outside the room. Laser and microwave beams reflected off these surfaces are modulated with the information and pose the same threat.
Vibrations caused from talking in a room can be transferred along air ducts, plumbing, walls, ceilings, etc. These vibrations can be intercepted and monitored by persons several floors or rooms away. This means that even though a room has been cleared of
eavesdropping devices, the voice information from within that
room may still be vulnerable.
The ANG-2200 system sets up a perimeter of masking noise around a room that creates a sound barrier to disrupt voice leakage. The TRN-2000 transducers are designed to inject masking noise onto the room surfaces while the OMS-2000 speakers are used to provide protection in open air spaces such as in closets, above ceiling tile, and in crawl spaces. This method provides a much
greater masking noise envelope while producing less obtrusive
noise in a room than a loudspeaker.
Truely Random Noise
The ANG-2200 contains two separate random noise generators. There are several products in a host of markets that use noise generators, but most of these use pseudo-random noise. Pseudo-
random noise is generated by a mathematical formula or a precalculated list of values and is in most cases predictable.
This predictability allows a sophisticated eavesdropper to correlate on this predicted noise and extract the room’s information. True random noise is naturally generated and completely unpredictable and eliminates this threat. The ANG-2200 uses true random noise.
The human voice produces many frequencies when producing speech. The frequencies and their strengths are dependent on the individual and the sound he or she is making. The spoken word typically produces frequencies in the range of 100Hz to 6000Hz.
Intelligible speech resides in the range of 300Hz to 3000Hz. This means that though the voice has lower and higher frequencies, the ability to understand the differences in sounds in order to create speech consists of a smaller frequency range.
The ANG-2200 shapes its noise spectrum to allow for more energy within the intelligible frequency band. This shape allows for greater efficiency, better protection, and a lower obtrusive noise level.
The ANG-2200 uses a combination of transducers and speakersplaced strategically throughout a target area to create a blanket of masking noise that covers private conversations from eavesdropping. Each transducer utilizes adapters for mounting to a variety of surfaces such as walls, windows, ductwork, plumbing, etc.
When transducers are mounted to surfaces, the surface’s material can change the shape of the ANG-2200’s frequency spectrum, altering the effectiveness of the noise. The LF and HF slope controls are used to equalize the noise back to the correct shape that is required to mask intelligible speech. The two separate outputs allow the user to tailor the noise for separate surface materials, allowing greater flexibility and increased protection.
The ideal transducer installation would be accomplished during construction or remodeling where sensitive points in the structure can be protected with transducers built into the building’s structure. If this is not possible, the transducers can be placed directly onto wall surfaces. If visual appearance is a problem, the transducers should be disguised or covered accordingly.
Determine the quantity of TRN-2000 transducers needed using the guidelines below:
WALLS - One transducer placed every eight linear feet, centered between floor and ceiling. Mount on or within six inches of a stud.
FLOOR and CEILING - One transducer centered on every sixty-four square feet. (Use the OMS-2000 speaker for drop ceiling.)
WINDOWS - One transducer placed on every major frame of glass within six inches of the corner.
DOORS - One transducer placed adjacent to the center hinge on the doorframe.
Note: “Shielded Screen Rooms” are shielded against R.F. devices transmitting out of the room, but not necessarily against acoustic leakage. During Construction or remodeling of a screen room, the transducers can be mounted on the frame members, and then acoustic insulation and a decorative panel can be installed to the inside wall surface. This will help isolate the noise generated from
the room as well as decrease the acoustic leakage out of the room.
Features The ANG-2200 offers two channels each with a truly random noise source. Both channels have a separate high and low frequency control in order to compensate for loses found in the environment's material composition.
ANG-2200 Features: 2 seperate channels, Truly random noise sources, High Frequency and Low Frequency Controls, Overload Protection.
•Weight: 1.2 lb. (.5 Kg)
•Output Max: 10 V p-p @ 6 ohms
•Min. Load: 2 ohms
•Frequency: 125 Hz 4 kHz
•Power: 12Vdc, 1A
Options: email for details:
•TRN-2000 Transducer used to inject acoustic noise into walls, ceilings, windows, plumbing, and air ducts.
•OMS-2000 Omnidirectional Speaker used to project acoustic noise into drop ceiling air spaces, closets, crawl spaces, and air ducts.
•WMT-2000 Transducer Window Mount provides a safe method of attaching the TRN-2000 to a glass surface.
1. On Indicator
2. Power Switch
3. Level Indicator- Output 1
(Last Red Display Indicates Voltage Clipping)
4. Level Control - Output 1
5. Low Frequency Control - Output 1
6. High Frequency Control - Output 1
7. Current Overload Indicator - Output 1
8. Level Indicator- Output 2
(Last Red Display Indicates Voltage Clipping)
9. Level Control - Output 2
10. Low Frequency Control - Output 2
11. High Frequency Control - Output 2
12. Current Overload Indicator - Output 2
1. Positive Terminal - Output
2. Negative Terminal - Output
3. Negative Terminal - Output 1
4. Positive Terminal - Output 1
5. DC Power In - 15VDC @ 1A