L-Acoustics V-DOSC, Руководство оператора

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L-ACOUSTICS V-DOSC Manual Version 4 6/29/2005 Page 110 of 158
A second V-DOSC enclosure is then stacked on top of the first and mechanically connected using the
rotating legs and U pins in the same way. With reference to the installation parameters calculated in
ARRAY or SOUNDVISION, angle straps are connected between the two enclosures and two spacer
blocks are then inserted between the enclosures on the sides to set the correct tilt angle for the
second enclosure. Never use a single spacer block in the center of the cabinets – the wood thickness
is only 15 mm at this point and the overall weight of the stacked system could cause damage to the
bottom enclosures. Verify the tilt angle for the second enclosure using a digital inclinometer and fine
tune the angle by adjusting spacer block positioning, if necessary.
NOTE: Since the rear edges of the cabinets are touching when enclosures are stacked, this introduces
an additional 1degree for angle straps when cabinets are stacked versus flown. Angle strap values for
flown and stacked systems are tabulated below:
Table 15: Angle Strap Values
ANGLE
COLOUR
CODE
ANGLE
STRAP
LABEL
NOMINAL
FLOWN
ANGLE
NOMINAL
STACKED
ANGLE
Gold BUMP 1.6 N/A
Yellow 0.75 / 5.5 0.75 / 5.5 1.75 / do not use
White 1.3 1.3 2.3
Red 2 2 3
Blue 3 3 4
Green 4 4 5
Angle strap values should be selected by taking this 1 degree difference into account for stacked
versus flown. For example, if ARRAY 2004 or SOUNDVISION simulations indicate that a 4 degree
angle is required between enclosures 1 and 2, select a 3 degree angle strap for the actual installation.
Angle differences can also arise due to tolerance variations in enclosure construction and spacer block
placement. Use a digital inclinometer to determine the effect of these tolerance variations and
minimize their impact.
The same procedure is followed for all other enclosures of the array until stacking is completed.
NOTE: it is easier to place spacer blocks between enclosures as the array is built instead of inserting
them afterwards.
The correct site angle for the entire array is obtained by fine adjustment of the BUMP2 screwjacks.
Focus can be checked by sight - looking from the rear of the array through the small space between
the top enclosure and the second one, the lower wall of the top enclosure should be aligned so as to
aim towards the rearmost seats of the audience. Alternatively, from the highest section of the
audience area, if you can see the top of the upper V-DOSC enclosure, you are out of the coverage
pattern. Focus can also be performed by placing a laser on the upper wall of the top enclosure and a
visual check should be made with respect to the lower wall of the bottom enclosure of the array to
ensure that closest members of the audience are covered.
Connection of the array to the amplifier racks can be performed as soon as stacking is complete. To
avoid confusion, connect cables to the amplifier racks first and parallel jumpers between V-DOSC
enclosures last – this way, reversal of cable sex is avoided (i.e., the output of the rack is female, which
can be confusing to the average stagehand). Remember to parallel 3 V-DOSC enclosures maximum.
When unstacking the array, first remove all loudspeaker cabling. As V-DOSC enclosures are
unstacked, remove the spacer blocks first since this makes it easier to remove the U pins when
disconnecting the rotating legs. Dolley boards can be attached and enclosures directly unstacked onto
their wheels.