Operating Modes; Standard Mode; Cardioid Mode - L-Acoustics SB18 User Manual

SB18 SB18 SB18 / SB18 SB18 SB18 SB18 SB18
USER USER USER MANUAL USER MANUAL MANUAL MANUAL
VERSION 2.1
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OPERATING MODES

OPERATING MODES OPERATING MODES OPERATING MODES
3.1

STANDARD mode

In STANDARD mode, a subwoofer system operates with an omni-directional directivity pattern.
It corresponds to the use of SB subwoofers as single elements or as a standard subwoofer array.
The SB18 subwoofers are driven either by the LA8 or the LA4 amplified controller with a choice of two different
factory presets, each one offering a distinct upper frequency limit in order to optimize the acoustic coupling between
the subwoofer system and a main full-range system.
Single element
Vertical
3.2

CARDIOID mode

In CARDIOID mode, a subwoofer system produces a rear SPL rejection.
It corresponds to the use of an array of four SB enclosures with one reversed element, i.e. turned towards the rear.
The SB18 subwoofers are driven either by the LA8 or the LA4 amplified controller with a choice of two different
factory presets, each one offering a distinct upper frequency limit in order to optimize the acoustic coupling between
the subwoofer system and a main full-range system. Both presets feature delay settings optimized for SB18 arrays in
cardioid configuration.
Vertical
Directivity pattern
Horizontal symmetric
Central rear rejection
Delay settings
When combining a line source with subwoofers, delays may have to be added to the presets. Refer to the
LA4 or LA8 PRESET LIBRARY user manual to obtain the pre-alignment delay values.
Grouping subwoofers
Place the subwoofer enclosures side by side. If not possible, the maximum distance between two adjacent
acoustic centers must be 2.8 m or 1.7 m whether the upper frequency limit of the subwoofer system is 60 Hz
or 100 Hz, respectively.
SB18_UM_EN_2.1
/ SB18 SB18 SB18 SB18 SUBWOOFER
i m
SB18 in standard configuration
Horizontal
On-end
SB18 array in cardioid configuration
[PRESET] [SB18_60_C] or [SB18_100_C]
Horizontal
On-end
Increased rejection on the side of the reversed subwoofer
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[PRESET]
Block
LF extension (-10dB)
Directivity pattern
Horizontal asymmetric
[SB18_60] or [SB18_100]
LF extension (-10dB)
32 Hz
Directivity pattern
Omni-directional
32Hz
Block
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