User guide

VoiceLift System with PVS 405D • Features and Operation 20
Integrated DSP
Digital signal processing (DSP) is a specialized circuit that processes audio signals that
have been converted to digital form. The VLR 102 Receiver has a built-in DSP that
suppresses feedback while maximizing sound quality and intelligibility.
As feedback occurs, up to 15 dynamic filters engage, automatically detecting and
eliminating unwanted feedback frequencies. The dynamic filters are notch filters, providing
up to 30 dB of attenuation for feedback frequencies caused by high microphone levels,
room resonance, or proximity of the microphone to a speaker.
The DSP retains a maximum of 10 filters. After a period of 2 minutes, if the number of
filters is greater than 10, the oldest filters begin to slowly release until the number of
dynamic filters in use equals 10. This process assures that five filters are always available
in case of unexpected feedback (see the VoiceLift System Installation Guide to set the
dynamic filters).
Receiver Dome and Base Plate
The tinted sensor dome filters ambient light but lets the IR signals from the microphone
pass through to the sensors. The dome is attached to the receiver base plate by four tabs
that are inserted into slots on the base plate.
O
N
12
CTS-2
MIX
TONE
RS-232
AUX IN
CTC
+
RLY
Tx
IN
Rx
C
NO
OUT IN
1
2
3
4 5
6
7
8
Figure 20. VLR 102 Receiver Base Plate
a
— Input (In) port
e
— Auxioiary input (Aux In) port
b
— Output (Out) port
f
— Contact input (CTC) port
c
— Mix and Tone DIP switches
g
— Relay (Rly) port
d
— $S-232 configuration port
h
— Tab with arrow
i
— Dome LED