JBL SRX900 Series, Руководство пользователя

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User Manual
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14 - SUBWOOFERS
14.2 RECOMMENDED CARDIOID SETUPS
Cardioid configurations are typically differentiated by the ratio of front-facing to rear-facing cabinets, the spacing between stacks, and
the position of rear-facing subwoofers within the stacks. Lower ratios produce higher rejection, higher ratios result in lower rejection. The
SRX9xxS factory presets were engineered to work with blocks having 2:1 and 3:1 ratios, with 2:1 delivering the greatest rear rejection.
Subwoofer arrays designed around a 2:1 ratio can easily generate broadband rejection of 20 to 30 dB. It is NOT advised to go below
2:1 or above 3:1 ratios. If larger arrays are desired, combining cardioid blocks into bigger arrays is possible. Using LAC-3 to predict the
expected coverage of complex arrays is suggested to ensure the intended coverage suits the desired application.
Example 1: 2:1 horizontal stack Example 2: 2:1 on-end
Example 3: 3:1 horizontal stack Example 4: 3:1 on-end
14.1 CARDIOID SUBWOOFERS
In some situations, the omnidirectional nature of subwoofers is desirable, but in others, directional coverage is required. The most
common use case for directional subwoofers involves preventing excessive low frequency energy from reaching the stage. A single sub-
woofer radiates omnidirectionally, but cardioid coverage can be achieved with an array of subwoofers in which the physical orientation
of some cabinets is reversed and the Rear speaker mode selected. The Rear speaker mode sets the DSP parameters to optimize the
system to provide the maximum amount of cancellation possible for most standard configurations without the need for any user DSP
changes.