User Manual

10
position.
4. Increase the output level until the LOOPBACK indicator shows the middle reading – the red light
should be on the 10
th
segment of the bargraph.
5. Place the DNG-MIC where a potential listening device could be hidden or a person carrying
a recorder or a microphone could stand/sit. Check that the LOOPBACK reading is not less
than 10. Increase the level if necessary. Probe all places where a person could stand or sit.
Repeat the tuning for spaces above the ceiling tiles, in closets/crawl spaces, ventilation channels,
etc.
VERIFICATION
When inspecting for acoustic leakage, a "Known Sound Source" such as a cassette or compact disc
player should be placed in the center of the target area. Set the volume to a normal level for
conversation in that area and leave the DNG-2300 off. Carefully probe any surface from the inside
or outside that is connected to the target area, including windows, doors, plumbing, air ducts, etc.
The identification of the KSS with the contact microphone will expose the existence of a possible
acoustic leak; these locations should be noted. Turn on the DNG-2300 and listen again for the KSS
to verify effective masking. The KSS should not be heard through the generated noise. Adjust levels
as required.
SPECIFICATIONS
Digital Noise Generator DNG-2300
Size 1.7 x 5.9 x 10 in. (4.4 x 15 x 25.4 cm)
Weight 2.2 Kg
Output Max 2 x 8W
Min. load channel
1,2
3 ohms
Min. load channel
3
8 ohms
Frequency 250-5000 Hz
Power 110 V 60 Hz (220V 50 Hz)
Transducer TRN-2000
Size 3 x 1.25 in. (7.6 x 3.1 cm)
Weight 1 lb (454 g)
Impedance 6 ohms
Omni Speaker OMS-2000
Size 5 x 5.75 in. (12.7 x 14.6 cm)
Weight 2 lb. (907 g)
Impedance 24 ohms
Probe microphone DNG-MIC
Output Level 1 V
Weight 110 grams