The Stealth DNG-2300

The Advanced Digital Noise Generator

The Stealth DNG-2300 is designed to prevent listening though devices that cannot be detected by conventional countermeasures and installed around the perimeter of a room – wired wall microphones, contact microphones, AC outlet transmitters and window systems based on the reflection of laser/infrared/microwave beams. It is an excellent addition to high level countermeasures.
It 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.

It is well-known that sound distributes though 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 Stealth DNG-2300 can render these devices useless. It produces non-filterable acoustic noise which is transferred to constructions by transducers and speakers. TRN 600, TRN 600S or REI’s TRN-2000 is the recommended transducer for use with the Stealth DNG-2300. It has optimal power parameters and can be set on different types of surfaces. The TRN 600(S) 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-600(S) transducer can be supplied with adapters for mounting on walls, ceilings, windows, etc.

The speaker OMS-2000 can also be used with the Stealth 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.



The Stealth 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.



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  Stealth DNG-2300 has a range of 250-5000 Hz which is optimal to cover all types of voices and suppress all listening devices.



The  Stealth 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.



The  Stealth 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.



The  Stealth DNG-2300 is supplied with AC power cable and user manual. The TRN 600and the OMS-2000 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.


It protects from
- Electronic stethoscopes (contact microphones)
- Microphones built in the walls or other constructions
- Laser and microwave surveillance systems using reflections from the windows
- Other vibro-accousic ways of information’s leakage
- Frequency response: 250-6500 Hz
- Power: 110 V AC, 220V AC




Digital Noise Generator DNG-2300


1.7 x 5.9 x 10 in. (4.4 x 15 x 25.4 cm)


2.2 Kg

Output Max

2 x 8W

Min. load channel 1,2

3 ohms

Min. load channel 3

8 ohms


250-5000 Hz


110 V 60 Hz (220V 50 Hz)


Transducer TRN-2000


3 x 1.25 in. (7.6 x 3.1 cm)


1 lb (454 g)


6 ohms


Omni Speaker OMS-2000


5 x 5.75 in. (12.7 x 14.6 cm)


2 lb. (907 g)


24 ohms


Probe microphone DNG-MIC

Output Level

1 V


110 grams


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