BSS Audio FDS 360, User Manual

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21
Modes of Operation
14.0 Modes of Operation
The FDS-360 can be configured as either a stereo 2-way, or mono three/four-
way electronic crossover. Further possibilities within this framework can be
utilised to allow more flexibility.
For applications where only a three way system is used, the fourth way or
band will not be directly used. This can be configured to operate as a full
range (or some form of high pass function) output, with level control, LED
indicators and limiter. This buffered output can be used to drive an auxiliary
sound source such as back stage area, bar area or other full range system. To
utilise this function, a special frequency card is required in position FC3
which bypasses the normal high pass filter sections.
Refer to section 18 for
more information on this bypass card.
14.1 Mono Three
Way with Extra Full
Range Buffered
Output
When operating in the mono three/four-way mode, the input connector and
circuitry for channel two is not utilised. Where a speaker system is configured
as a three way with sub-woofer, using band one is derived from the CHN 2
input section, allowing the operator to drive the sub-woofers from an
independent signal send (possibly an effects send) rather than from the main
stereo left/right sends. To implement this mode of operation the factory fitted
wire link on the barrier strip between CHN 1 SEND and BAND 1 IN should be
removed, and replaced by linking CHN 2 SEND and BAND 1 IN. The same
wire link can be used, and inspection will show that the link is just rotated
around the BAND 1 IN position.
As standard, the FDS-360 has a subsonic filter set for 30Hz, and is some
applications when driving sub-woofer speakers it can be advantageous to
change this down to 15Hz to allow more low frequency energy to pass. This
can be implemented internally,
refer to section 17 for further information.
It will be apparent that this feature of using the CHN 2 input as auxiliary input
is not specific to BAND 1, and can be easily connected to any of the bands IN
terminals. For example, when using the option as in section 12.0 previously,
the band four section can be driven from this auxiliary input to provide
complete and independent control regardless of the main left and right stereo
feeds.
14.2 Operating a
Sub-Woofer system
from an Effects
Send
As mentioned in section 11.5, 'Mono Low Switch', when operating in the
stereo 2-way mode, the two LOW output sections can be summed together to
provide a mono signal feed for the low frequency speakers. This facility can
also be used when using two
FDS-360
units in a stereo three or four way
speaker system. A flexible wire lead should be connected to join together the
MONO LOW TIE terminals of the barrier strip of each
FDS-360 . The two
mono low switches on the front panels must also be operated. This allows the
two units to be permanently tied whilst allowing the mono option to be
selected by the front panel switches as required.
14.3 Mono Low
between separate
units