PreSonus StudioLive AI Series - Manual (Page 48)

4 Universal Control-AI and VSL-AI
4.9 Smaart System Check Wizards
StudioLive ™ AI Software Library
Reference Manual
44
4.9.2 Smaart System Delay Wizard
Using multiple sets of speakers in a live performance can make a huge difference
in the quality of the sound. Rather than relying on a pair of front-of-house speakers
to fill the entire room, you can create listening zones throughout the room so
that your front-of-house system only needs to be loud enough to cover the
front of the room. This allows you to lower the level, give the front row listeners’
ears a break, and get better fidelity from your speakers. Sounds great, right?
However, it’s not as easy as just bringing an extra pair of speakers. Any additional
sets of speakers will need to be delayed; otherwise the audience will perceive
that the sound is coming from the walls, rather than from the stage. Even
worse, since electricity travels much faster than sound, listeners in the rear of
the room are likely to hear the sound coming from the nearest set of speakers
before they hear the sound from stage, which can dampen the attack and
intelligibility of the sound and create an unpleasant phasing effect. To compensate,
you need to delay the signal going to the additional sets of speakers.
Sound travels at a rate of 1,130 feet per second, providing that the temperature,
humidity, and air pressure are all “normal.” Therefore, it takes 1 ms for sound to travel
1.1 feet. But what if you’re setting up for an outdoor show in, say, Baton Rouge,
Louisiana, in August, when the temperature and humidity are unpleasantly far above
“normal”? Your calculations might be a little off, unless you happen to be a whiz at
calculating the effect of barometric and atmospheric pressure on sound waves.
The SSD wizard is an automated process that calculates and sets the correct
delay time between two full-range systems. The purpose of this wizard is to
set the delay time for a secondary system that is being fed from one or more
subgroups. No calculators, slide rules, or finger-counting are necessary!
STAGE
FOH L FOH R
Side Fill
(left)
Side Fill
(right)
Rear Fill
(left)
Rear Fill
(right)
30 Feet
40 Feet
37 Feet
inconveniently positioned column
30 Feet