MACKIE 2-Way High-Definition Powered Loudspeaker HD1221 - Manual (Page 9)

WARNING: Installation should only be done by
an experienced technician. Improper
installation may result in damage to the
equipment, injury or death. Make sure that the
loudspeaker is installed in a stable and secure way in
order to avoid any conditions that may be dangerous for
persons or structures.
The HD1221 speaker is designed to sit on the floor or
stage as the main PA or as monitors. It may also be pole-
mounted via the built-in socket on the bottom of the
cabinet. Be sure the pole is capable of supporting the
weight of the HD1221. The Mackie SPM200 is a great
option when using a sub. The HD1221 may also be flown
horizontally or vertically via its 12 integrated fly points
as detailed on page 11.
Check to make sure that the support surface
(e.g., floor, etc.) has the necessary mechanical
characteristics to support the weight of the
loudspeaker(s).
When pole-mounting loudspeakers, be sure that they
are stabilized and secured from falling over or being
accidentally pushed over. Failure to follow these
precautions may result in damage to the equipment,
personal injury, or death.
As with any powered components, protect them from
moisture. Avoid installing the loudspeaker in places
exposed to harsh weather conditions. If you are setting
them up outdoors, make sure they are under cover if you
expect rain.
Placement
180˚
You can create a horizontal array by placing the
cabinets side-by-side. However, you should have a good
understanding of the relationship between the splay
angle (the angle between the facing sides of the
cabinets) and frequency cancellation effects between
cabinets.
When two cabinets are positioned side-by-side such
that the rear-angled faces of the enclosures are
parallel, the splay angle will be 90º. This matches the
90˚ horizontal coverage pattern of each individual
HD1221; the interference between the two cabinets will
be minimized, but the total coverage of 180˚ may be too
wide for some applications (see Figure A). The mid and
high frequencies may also be reduced for those in the
center who are too close to the loudspeakers.
Reducing the splay angle will reduce the total
horizontal coverage, but it also creates an area both
speakers are covering. Instead of a nearfield hole,
this will cause comb-filtering effects in the frequency
response in the overlapping area. The smaller the splay
angle, the more energy will be delivered on-axis, but the
comb-filtering effects will get worse at the same time
(see Figure B).
Experimentation and experience will help you find
the right trade-off for your application. In the end, the
correct placement will depend on the environment and
the necessary audience coverage.
Two HD1221s horizontally arrayed with 180˚
coverage with no interference.
Two HD1221s horizontally arrayed with 110˚
coverage with center interference.
110˚
Interference
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Owner’s Manual
Owner’
s Manual
Figure B Figure A