Operating instructions

18
CHAPTER 4
19
CHAPTER 4
towards the stage to keep them in phase at both the mix
position and throughout the total array coverage.
Similarly, when M3D-Subs are stacked on the oor below
your MILO array, they may be several feet closer than the
MILO array through most of the coverage, keeping them in
phase (provided the distance is 4 feet or less with the M3D-
Subs being closer).
NOTE: There is no polarity switch on either
the MILO or the M3D-Sub; both are wired pin
2 “hot” (positive acoustic pressure when a positive
pulse is applied to pin 2), making their integration
when co-planar - and in close-proximity – easier
when own or stacked in the same array.
NOTE: When both a MILO loudspeaker and
an M3D-Sub are used in their full-range
conguration (e.g. looped audio or the same audio
feed), their polarities should be kept the same if
they are co-planar or near each other. If they are
separated by a greater distance – or delay must be
used between them – a measurement system such
as SIM should be used to determine the correct
delay and polarity.
!
CAUTION: When daisy-chaining, make
sure that the source devices can drive the
total load of the paralleled array. (See Audio Input
section, page 9)
Adding a LD-1A/LD-2 Line Driver
Driving MILO loudspeakers and M3D-Subs with the same
signal from different outputs using a line driver allows
adjustments to the gain of each sub-system, and could be
used effectively to compensate for the ratio of loudspeakers
or acoustical conditions. If the gains are adjusted to the
same level, the combined response is identical to a daisy-
chain conguration.
Using the LD-1A or LD-2’s Lo-Cut lter optimizes MILO’s
headroom and reduces the area of overlap; the MILO
loudspeakers in the array receive their signal following a
high-pass lter, while the M3D-Subs apply their normal
internal crossover frequencies to a full range signal. This
conguration results in a smooth frequency response
through crossover and reduces the overlap frequency range
between the loudspeakers.
To drive MILO loudspeakers from the Mid-High output of
an LD-1A line driver (Figure 4.5) or LD-2 line driver (Figure
4.6), engage the Lo-Cut lter with no polarity reversal on the
M3D-Sub’s output when co-planar and in close-proximity.
Since an M3D-Sub rolls off rapidly after 80 Hz, there is no
need to engage the polarity reversal on the sub’s output.
Figure 4.5: The LD-1A line driver
Figure 4.6: The LD-2 line driver
M3D-Subs should be kept as close as possible to your
MILO loudspeakers to avoid phase errors and cancellation
in some seating locations. If M3D-Subs and MILO
loudspeakers are own side-by-side, they should not be
separated by more than 3 feet.
NOTE: Placing the M3D-Subs more than 4
feet away from your MILO array may require
setting M3D-Subs/MILO loudspeakers to opposite
polarities.
With a 2:1 ratio, an M3D-Sub produces roughly 3-6 dB rise
below 100 Hz, which is often desirable. The LD-1A or LD-2
Lo-Cut Filter keeps the build-up of energy from 100-200
Hz to a minimum, resulting in the smoothest frequency
response you can achieve for an M3D-Sub/MILO combined
conguration.
NOTE: When driving MILO loudspeakers
from the Mid-Hi output of the LD-1A or LD-2
line driver, with the Lo-Cut lter engaged and the
M3D-Subs in their full-range conguration, their
polarities should be kept the same if they are co-
planar or near each other. If they are separated by a
greater distance – or delay must be used between
them – a measurement system such as SIM should
be used to determine the correct delay and polarity.