Placement; Room Acoustics - Mackie DLM12 Owner's Manual

Placement

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.
A DLM loudspeaker is designed to sit on the floor
or stage as part of the main PA or as a monitor. 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 loudspeaker. The Mackie
SPM300 is a great option when using a DLM12S
subwoofer, as it allows for greater extension than
most other poles available north of the South Pole.
A DLM loudspeaker may also be flown via its three
integrated fly points as detailed on the next page.
Be sure to read the PA-A3 Eyebolt Installation
Instructions, as well.
Or maybe you prefer to mount DLM loudspeakers on
the wall. This is possible with the SWM300 Swivel Wall
Mount Kit. Be sure to read the SWM300 Swivel Wall
Mount Installation Instructions.
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.
16
DLM8/12 Powered Loudspeakers

Room Acoustics

Room acoustics play a crucial role in the overall
performance of a sound system. Here are some
additional placement tips to help overcome some
typical room problems that might arise:
• Placing loudspeakers in the corners of a room
increases the low frequency output and can
cause the sound to be muddy and indistinct.
• Placing loudspeakers against a wall increases
the low frequency output, though not as much
as corner placement. However, this is a good
way to reinforce the low frequencies, if so
desired.
• Avoid placing the speakers directly on a
hollow stage floor. A hollow stage can resonate
at certain frequencies, causing peaks and dips
in the frequency response of the room. It is
better to place them on a sturdy stand designed
to handle the weight of the DLM loudspeaker.
• Highly reverberant rooms, like many
gymnasiums and auditoriums, are a
nightmare for sound system intelligibility.
Multiple reflections off the hard walls, ceiling,
and floor play havoc with the sound. Depending
on the situation, you may be able to take some
steps to minimize the reflections, such as
putting carpeting on the floors, closing
draperies to cover large glass windows, or
hanging tapestries or other materials on the
walls to absorb some of the sound.
However, in most cases, these remedies are not
possible or practical. So what do you do?
Making the sound system louder generally
doesn't work because the reflections become
louder, too. The best approach is to provide as
much direct sound coverage to the audience
as possible. The farther away you are from
the speaker, the more prominent will be the
reflected sound.
Use more speakers strategically placed so they
are closer to the back of the audience. If the
distance between the front and back speakers
is more than about 100 feet, you should use
the DL2 delay to time-align the sound. (Since
sound travels about 1 foot per millisecond, it
takes about 1/10 of a second to travel 100 feet.)
Keep in mind that the DL2 channel and system
processor is a great way to compensate for some of
these issues. See pages 12-13 for more information
[11, 13].