MACKIE 2-Way High-Definition Powered Loudspeaker HD1221 - Manual (Page 10)

Room Acoustics
The HD1221 loudspeakers are designed to sound
neutral; that is, to reproduce the input signal as
accurately as possible.
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:
• Avoid placing loudspeakers in the corners of
a room. Doing so increases the low frequency
output and can cause the sound to be muddy
and indistinct.
• Avoid placing loudspeakers against a wall. This,
too, 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 the loudspeakers on a sturdy
stand designed to handle the weight of the
HD1221.
• Position the loudspeakers so the high-
frequency drivers are 2 to 4 feet above ear
level for the audience (make allowances for a
standing/dancing in the aisles audience). High
frequencies are highly directional and tend to
be absorbed much easier than lower
frequencies. By providing direct line-of-sight
from the loudspeakers to the audience, you
increase the overall brightness and
intelligibility of the sound system.
• 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 a
delay processor 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 VOICING MODE switch is a
great way to compensate for some of these issues. See
page 7 for more information.
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HD1221
HD1221