15
201401/IvxIM_v2.2
JBL Intellivox Installation Manual
EXTERNAL AMBIENT SPL/TEMPERATURE SENSOR
The pinout of this connector is as follows:
Although accessed via the same connector, the external
ANS microphone and temperature sensor functions are
independent of each other and either or both may be used,
as required. The use of the optional JBL combined Ambient
SPL/Temperature sensor is recommended, although either
of the two functions may be used alone if wished.
The diagram above illustrates how this connector should
be wired to the optional combined sensor using twin
twisted-pair cable with an overall screen. Note that there
are two AGND terminals on both the Intellivox and the
sensor; care should be taken not to confuse these, and in
particular, not to connect AGND to GND at any time.
External Ambient SPL Sensor
The Intellivox incorporates an autogain algorithm which
intelligently alters the volume of the audio according to the
ambient noise level. An internal microphone is fitted to
monitor the ambient noise level in the gaps in programme
material. The autogain function is activated and adjusted
via WinControl. This automatic volume adaptation feature
will only give good results if the signal measured by the
microphone is truly representative of the diffuse ambient
noise level, and in some circumstances it may be preferable
to monitor the ambient noise at a position remote from the
Intellivox itself. Connecting the external ambient noise
sensor automatically disconnects the internal microphone.
Care should be taken in selecting a suitable location for the
external sensor; it should not be near direct sound sources
such as people talking, air conditioning system outlets, or
other constant noise sources such as electrical plant, etc.
The most favourable external sensor locations are walls or
ceilings (height > 3 m) within the coverage range of the
Intellivox.
Temperature sensor
The external temperature sensor is for activating the
Intellivox’s frost detection system, and should be
connected if it is anticipated that the ambient temperature
may drop below 0 °C. If it does, an internally-generated
pilot tone is applied to the drivers, warming the voice coils
slightly, and thus preventing any build-up of moisture in
the magnet gap. Note that this pilot tone is always
generated if the internal load monitoring surveillance
function is enabled. In that case the ambient temperature
sensor is not required.
PIN NO.
LABELLED
FUNCTION
1
MIC
ANS mic +
2
AGND
ANS mic -
3
NTC
Temp
4
AGND
Temp Sensor -
5
GND
Screen
NTC
AGND
Mic
AGND
Shield
Shield
AMBIENT SPL /
TEMPERATURE
SENSOR
5
4
3
2
1
Pair 1
Pair 1
Pair 2
Pair 2
INTELLIVOX
fig.11.1 - External ambient SPL/Temperature
sensor connector
fig.11.2 - External ambient SPL/Temperature
sensor connections
5 4 3 2 1
1 2 3 4 5
or
