Listening devices, bugs, thin walls or the carrying of a voice don’t stand a chance against the DNG2300-4 White noise generator sound masking system.

When the white noise generator is paired with the transducers and speakers, it produces a low level audible interference by creating vibrations onto the surface of the walls in the protected space. If any form of eavesdropping devices are used it will block the voices and instead it will pick up and relay back the vibrational white noise created by the counter surveillance device. You’ll want to have a good spread of transducers and speakers amongst the wallspace, the number will depend on the size and construction of the room. ( all device also sold separately) installation required. 

It is well-known that sound distributes through walls, doors, windows and other constructions. In some materials sound travels even better than through air. For example, water is a good conductor and a heating system can pass a conversation out of a room. Eavesdroppers take advantage of this with the use of contact microphones. These microphones pick up the vibrations from the air ducts, plumbing, structures, walls, windows, doors, floors, ceilings and more. The microphones may not be in the same room as the conversation, but may be several floors or rooms away attached to a pipe or other fixture. The DNG-2300 can render these devices useless. It produces non-filterable acoustic noise which is transferred to constructions by transducers and speakers. REI’s TRN-2000 is the recommended transducer for use with the DNG-2300. It has optimal power parameters and can be set on different types of surfaces. The TRN-2000 injects most of its power into surfaces while only a tiny part of the noise gets inside a room. This does not force people to speak louder. The TRN-2000 transducer can be supplied with adapters for mounting on walls, ceilings, windows, etc. The speaker OMS-2000 can also be used with the DNG-2300. It does not inject the noise into the surfaces but  radiates it into surrounding space. The OMS-2000 is usually used in air ducts, ceiling tiles, etc

TRULY RANDOM NOISE

The DNG-2300 consists of 3 independent white noise digital generators. “White” means that the noise is fully random and is equally distributed along the voice spectrum. This distribution provides complete resistance against the filtering of a conversation. Another feature of white noise is its unpredictability i.e. there is no method to wipe it out from a recorded conversation. 

VOICE MASKING

Men’s and women’s voices consist of lots of frequencies simultaneously produced during speech. These frequencies lie between 100 Hz and 6000 Hz. Listening devices usually have a narrower range mostly because of size limitations, the scheme of the device and battery time. The DNG2300 has a range of 250-5000 Hz which is optimal to cover all types of voices and suppress all listening devices. 

OPERATION

The DNG-2300 uses a combination of transducers and speakers placed 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, ductworks, plumbing, etc. The three separate channels allow the user to tailor the noise for separate materials, allowing greater flexibility and increased protection. 

LOOPBACK INPUT

The DNG-2300 has an input LOOPBACK which allows easy and fast tuning to the necessary level of noise. Optional probe microphone DNG-MIC and probe stethoscope DNG-STET are used for the required measurements

Features:

3 Channel White Noise Generator x1 helps protect from

• Laser & Microwave surveillance systems using reflections from windows
• Electronic stethoscopes (contact microphones)
• Microphones built in the walls or other construction
• Other Vibro-Acoustic methods of information leakage

White noise generators are widely used for protecting premises against acoustic leakage eavesdropping. The SP2300 omnidirectional speaker is an important component for such system. While the transducers inject the generated noise into the surfaces and structures stopping distributing of sound through them, the role of the speaker is to fill voids, cavities and ventilation shafts with the audio interference to prevent leakage of sound through the air.

Creating of audio noise in the voids/cavities increases the general level of protection by preventing such kinds of listening as:

• Listening with the help of a wall stethoscope placed behind the construction adjacent to cavity (typically from a top floor behind the drop ceiling)
• Leakage of sound outside the target room through the void/cavities (for example, through the ventilation or common holes for the pipes of heating system)
• Bringing a wired microphone to a void or cavity
• Hiding a covert surveillance device in a void or cavity

Ventilation shafts and other voids leading outside the protected room

Ventilation makes it possible to carry out eavesdropping without penetrating into the target zone. Sound from the target room propagates through the shafts/voids and can be picked up remotely. In the case of sufficient distance a wired microphone can be run within the shaft. In order to prevent leakage of speech information the SP2300 can be positioned inside a void/shaft. If the void is not large enough to accommodate the speaker, the speaker can be disassembled and placed without the holders.

Since the SP2300 is assembled from 3 speakers, each of them can be used separately for smaller voids. Disassemble the SP2300 by removing the triangle holders, cut the cables, place the separate speakers where necessary and then connect again in series.

• Use 1 x SP2300 for a big shaft or a disassembled "1/3" speaker for a smaller void

Space behind the drop ceiling

Sound distributes in all directions; therefore, all conversations inside the target area can be easily picked up under the drop ceiling. The most popular methods of eavesdropping are:

1) Drilling a hole from the top floor in order to place a wired microphone or its tube extender behind the drop ceiling. This method is preferred over direct drilling into the room as the drop ceiling hides signs of work.

2) Placement a bugging device in the space under the drop ceiling.

The SP2300 can be placed behind the drop ceiling in order to protect from the mentioned listening methods. If there are no partitions behind the drop ceiling, the quantity of speakers can be selected in correspondence with the following suggestions:

• 1 x SP2300 speaker per each 9-10 square meters

Connection

Depending on the selected number of speaker, choose a wiring diagram from the below picture. Consider the generator's minimum load for the SPEAKERS channel (8 Ohm for the DNG2300)

The output power is divided between the speakers, so when there are more speakers, each separate unit will receive less power. The percentage shows the relative power produced by a speaker, comparing to the variant with a parallel connection of 3 speakers.

• "100% level" speakers are recommended for large ventilation shafts
• "50% level" – for regular voids/cavities
• "33% level" – for small voids/cavities

Combining levels can be done, but care should be taken to verify the load for the generator and correct output volume out of each speaker.

The percentage reflects the relative power, while the real output will also depend on the generator's volume control. Typically, when there are more speakers the volume should be set higher. To determine the sufficient level for the output channel it is necessary to conduct some tests with the help of an acoustic leakage probe. By creating a test sound in the room with the generator active it is possible to adjust the noise to such a level that the external probing does not capture any sound within or near the void/cavity.

In fact there  is not some additional describes.

1. Device supplied with the manual only

2. There is not any braket in supplier set

3. The power cord that installed in SP2300 is around 1 m. Lenght of cable from SP2300 to generator depends from square of wires, for exmple, if you will be use the cable with square 0.22 m2 the lenght from SP2300 to generator is up to 30 m, for square 0.75 m2 the lenght will be up to 60 m. The same as for OMS-2000 from REI..

The SP2300 speaker, when connected to a white noise generator, will create efficient interference to all mentioned kinds of eavesdropping. The DNG-2300 is the recommended white noise generator for the SP2300. It has a separate SPEAKERS output with adjustable volume and can feed up to 12 speakers simultaneously.

TD-2300 Transducer

• Compact design, fits great on windows, walls and other structures
• Includes mounting set to install on any surface
• Attractive design, looks good in any interior High power output, combined with compactness Fits equally well on windows, walls and other structures The included mounting set makes it possible to install the transducer on any surface Passes most of the generated noise into the desired construction in the form of vibration, while also producing less audible interference The frequency characteristics optimally correspond to the spectrum of human's speech Perfectly suited for the DNG 2300 white noise generator

The TD2300 vibroacoustic transducer is part of a complete counter surveillance protection system. It inducts noise into walls, floors, ceilings, windows and other surfaces of the building, preventing leakage of sound signals. To provide a sufficient level of protection the system consists of a number of transducers installed on different structures in the room and is connected to a generator. 

SP-2300 Acoustic Speaker

It is well-known that sound distributes through walls, doors, windows and other constructions. In some materials sound travels even better than through air. For example, water is a good conductor and a heating system can pass a conversation out of a room. Eavesdroppers take advantage of this with the use of contact microphones. These microphones pick up the vibrations from the air ducts, plumbing, structures, walls, windows, doors, floors, ceilings and more. The microphones may not be in the same room as the conversation, but may be several floors or rooms away attached to a pipe or other fixture. The DNG-2300 can render these devices useless. It produces non-filterable acoustic noise which is transferred to constructions by transducers and speakers. REI’s TRN-2000 is the recommended transducer for use with the DNG-2300. It has optimal power parameters and can be set on different types of surfaces. The TRN-2000 injects most of its power into surfaces while only a tiny part of the noise gets inside a room. This does not force people to speak louder. The TRN-2000 transducer can be supplied with adapters for mounting on walls, ceilings, windows, etc.

The speaker OMS-2000 can also be used with the DNG-2300. It does not inject the noise into the surfaces but radiates it into surrounding space. The OMS-2000 is usually used in air ducts, ceiling tiles, etc. TRULY RANDOM NOISE The DNG-2300 consists of 3 independent white noise digital generators. “White” means that the noise is fully random and is equally distributed along the voice spectrum. This distribution provides complete resistance against the filtering of a conversation. Another feature of white noise is its unpredictability i.e. there is no method to wipe it out from a recorded conversation. VOICE MASKING Men’s and women’s voices consist of lots of frequencies simultaneously produced during speech. These frequencies lie between 100 Hz and 6000 Hz. Listening devices usually have a narrower range mostly because of size limitations, the scheme of the device and battery time. The DNG2300 has a range of 250-5000 Hz which is optimal to cover all types of voices and suppress all listening devices. OPERATION The DNG-2300 uses a combination of transducers and speakers placed 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, ductworks, plumbing, etc. The three separate channels allow the user to tailor the noise for separate materials, allowing greater flexibility and increased protection. 3 LOOPBACK INPUT The DNG-2300 has an input LOOPBACK which allows easy and fast tuning to the necessary level of noise. Optional probe microphone DNG-MIC and probe stethoscope DNG-STET are used for the required measurements. SUPPLIED SET The DNG-2300 is supplied with AC power cable and user manual. The TRN-2000 and the OMS2000 are sold separately. Their quantity depends on the room size and the situation. The probe microphone DNG-MIC and the probe stethoscope DNG-STET are also sold separately. REMARKS REGARDING PREPARATION This instruction manual covers the installation, wiring, and testing of the DNG-2300. Because the DNG-2300 protects the perimeter of the target area, devices which may be planted in close proximity to the target speaker’s voice may not be jammed by the DNG-2300 system. Therefore prior to the installation of the DNG-2300 it is recommended to perform thorough sweep accompanied by a physical search. When performing detection and location the following tools can be used: radio field indicators (bug detectors), interceptors, frequency counters, counter surveillance probes, spectrum analyzers, etc. Contact your dealer for help in choosing the necessary tools or ordering a sweeping service. While the most accessible listening devices can be detected by the mentioned equipment, there are a lot of devices which can only be found by physical methods: wired microphones, fiber optic microphones, passive resonators, inactive remote controlled “dormant” devices, or other nondetectable devices. Therefore a physical search is a very important part of countersurveillance work.