Symetrix 572 SPL, Руководство пользователя

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572
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Off-Track Betting Parlors and Casinos
In these facilities, the crowd reaction is likely to be sudden and intense. If the program material
doesn’t have long enough silent spots for sensing, the 571 is a better idea since it works in real
time.
In casinos, be sure to place the to average the crowd and the machines, especially the dollar
machine with the 20-jillion dollar jackpot.
Museums
Now why would you want to put a 572 into a museum? When the museum has an overall paging
system. That when.
What about when the museum has automated exhibits? That’s not when. Use a 571 instead
because the 571 works in real time. The time delays between sensing periods and operating periods
would most likely result in sound systems that are too loud for the current ambient condition.
Airports, Train Stations, etc.
The 572 is ideally suited to managing the SPLs within airports and other transportation hubs.
Within airports, use at least one 572 per paging zone.
In subway stations, pick a speaker location that favors the crowd but still ‘hears’ the trains. Doing
so ensures that the level increases when a train is present.
Make sure that there are sufficient silent periods for sensing. You can use the mic-level page input
for the local paging mic and the line-level paging input for facility-wide paging. Use the music input
for background music, if any.
Race Tracks
Different race tracks have different noise sources. In auto racing, the cars usually make more noise
than the spectators. If you’re going to apply a 572 to a speedway, position the speakers so they
are in a good spot to pick up the cars as well as the crowd.
If this isn’t practical, consider using a small paging speaker(s), with a 70V transformer
1
that is only
used as a microphone. Use a moderate transformer tap, like 10 watts. You may even be able to do
away with the transformer. Use shielded twisted-pair cable and don’t forget to tie the shield to the
case of the speaker (or float it if it’s plastic or to avoid a ground loop.). Position the speaker so it
has a nearby view of the stands and connect it to the 572’s T
O
S
PEAKER
terminals. Do not connect
the amplifier to the F
ROM
A
MP
terminals. Instead, connect the amplifier directly to the other loud-
speakers.
In horse (and dog) racing, the spectators make more noise than the animals. In this case, the
spectator area speakers serve as expected, both for paging as well as for sensing.
Use a short A
VERAGING
T
IME
. Ensure that the program material has enough dead spots to ensure
frequent sensing. Definitely use a live mic when calibrating. Beware of acoustic feedback, espe-
cially when calibrating the M
AX
level.
1
The ElectroVoice PA15BT-7 or PA30-AT are both suitable units.