Sub Alignment - PRESONUS AI-Series Owner's Manual

4 System Configuration
4.2 Delay Systems

4.2.2 Sub Alignment

Outside. Outdoors, you are trying to maintain level as the noise floor of
the crowd begins to be at equal level to the PA in the intelligibility range.
When working outside, the delay system is used to overcome outdoor noise,
including (but not limited to) crowd murmur, concessions, generators, tractors,
babies, etc. At this point, the main system needs more support in order to
deliver the same perceived loudness as you get further from the source.
Once you have positioned and delayed your satellite system, use an SPL meter
to match the output of the main and delay systems at the measurement
point. If you are standing 20 feet from the left side of the main system and
30 feet from the left side of the delay system, and if the output of the main
system is 85 dB, the output of the delay system should also be 85 dB.
The 18sAI subwoofer has been designed and customized for use with
the full-range AI-series loudspeakers. It features three delay presets
to guarantee that your 4-way system stays in alignment:
0m
0M. Select this setting when the full-range system is directly over the
subwoofer (i.e., mounted atop using the SP1BK sub-pole accessory).
No delay is added to the subwoofer amplifier output.
1M. Select this setting when the subwoofer is about one meter from
the full-range loudspeaker—a typical distance when the loudspeaker
is on an adjacent tripod stand. A delay of about 2.9 ms is introduced
to the signal that is output through the subwoofer amplifier.
StudioLive
FOH Mix Position
1m
AI-Series Loudspeaker
™
Owner's Manual
SPL Meter
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