KV2 Audio SDD3 - Manual (Page 13)

SDD3 Setup
MENU
Units mode
Delay mode
Delay can be set in time (miliseconds) or in distance
(meters or feets depending on Units setup). When
switching between time and distance, the delay time
is kept and recalculated to each other. The delay
distance depends on the ambient temperature.
Units
It is possible to switch between metric (meters, °C )
and imperial (feet, °F) units, when switching between
each other, the distance is maintained.
Link AB
It is possible to link channel A and B delay setup,
when both delays are the same. When switching to
Link AB, the delay of both channels is set by
channel A.
LEVEL
Delay mode
Units mode:
Units
DELAY MENU
Units mode: Delay mode
time ( )
( )
metric
Link AB ( ) no
Cardioid polar characteristics
LEVEL
Units mode
Subwoofer mode
DELAY
Memory
Lock
Display
Temperature
MENU
MENU screen - Subwoofer mode
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LEVEL
Units mode
Subwoofer mode
DELAY
Memory
MENU
MENU screen - Units mode
Lock
Display
Temperature
Subwoofer mode
Cardioid setup
Bass is usually omnidirectional but by using a cardi-
oid bass array you can reduce bass feedback on
stage and also minimise noise pollution from events.
When using cardioid mode, the front subwoofer is
1/4 wavelength of the tuned cardioid frequency in
front of the rear subwoofer. The front subwoofer is
fed with a 1/4 wavelength delay compared to the
rear sub. This configuration results in a cardioid
polar response ,(because of addition and subtraction
of the subwoofer signals).
Cardioid calculation - example
Subwoofers distance (d) corresponds to 1/4
wavelength (λ) of the tuned cardioid frequency
(f).
Speed of sound (v) varies with temperature, for
20°C is approx 343m/s.
λ = 1 / 4f
d = v * λ
FRONT
SUB
REAR
SUB