Q-See QC40198 - Manual (Page 26)

INSTALLATION & CONNECTION
QC40198 User Manual
17 | P a g e
Figure 3-3
3.6 Connecting Audio Input & Output, Bidirectional Audio
3.6.1 Audio Input
This product uses BNC ports. Audio transmission is similar to video transmission. Try to avoid interference, keep
contacts snug and dry, and away from high tension current.
Figure 3-4
3.6.2 Audio Output
The audio output signal parameter is usually over 200mv
1KΩ (BNC). It can directly connect to low impedance
earphone, active sound box or amplifier-driven audio output device.(See Figure 3-5)
If the sound box and the pick-up cannot be separated spatially, it is easy to get reverb or squeaking feedback. If
feedback occurs, try these tips:
 Use better sound pick-up with better directing properties.
 Reduce the volume of the sound box.
 Using more sound-absorbing materials can reduce voice echo and improve acoustics environment
 Adjust the layout to reduce occurrence of squeaking