McIntosh MQ 104 Owners Manual

Page 2

Your M0 104 Custom Environmental Equalizer will give
you many years of pleasant and satisfactory performance.
If you have any questions concerning the operation or
maintenance at this instrument, please contact:

CUSTOMER SERVICE
McIntosh Laboratory Inc.

2 Chambers Street
Binghamton. New York 13903
Phone: 607-723-3512

WARNING: TO PREVENT FIRE OR SHOCK HAZARD.
DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE.

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Copyright © 1977 by McIntosh Laboratory Inc.

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Page 6

Designing for
Better Sound

McIntosh loudspeaker systems have a unique combina-
tion of moving or sound producing parts. cabinet, and
acoustic damping material. The designed relationship of
these many elements produces near perfect control of the
woofer cone motion. Motional control is particularly im-
portant at system resonance where other types of designs
lose control and cause ringing." Control is accomplished
at the expense of low frequency response which rolls off
below 150 Hz. Low frequency compensation provided by
the M0 104 is used to restore and extend bass response to
20 Hz. Room gain effects also occur at low frequencies.
Since compensation is necessary to restore low frequen-
cies to the speaker system. compensation for different
rooms can be combined at the same time. The design al-
lows control for different room gains that occur when the
speaker is placed on the floor in a corner. on the floor against
a wall away from the corner. or off the floor against a wall
away from the corner. The changes in low frequency output
due to room gain are small and relatively uniform. The
M0 104 provides the same basic low frequency compensa-
tion as used in earlier McIntosh Environmental Equalizers.
In addition. facilities are provided to correct room reso-
nances.

Sound intensity changes described as room resonances
occur due to reflections and counter reflections of the sound
from wall to wall and between floor and ceiling These
resonances can cause serious peaks and dips below 250 Hz
by as much as :15 dB. The sound that leaves the loud-

speaker may have smooth response, but a badly dimenv
sioned room (equal or multiple dimensions) will seriously
alter this response. Even a perfect loudspeaker will suffer.

The McIntosh M0 104 has an additional set of filters
designed specifically to equalize irregular low frequency
response caused by room resonances. There are eight pro-
grammable filter bands (four in each channel) provided.
Each filter can be programmed for frequency and band-
width. Each filter is adiustable for amplitude boost or cut.

Extensive testing of home living rooms and dealer lis-
tening rooms indicate that room dimensions influence the
performance of loudspeakers below 1000 Hz. The most
pronounced effects are measured below 250 Hz. Speakers
which appear to have no highs and sound boomy usually
are the victims of a poor listening environment. By elimi-
nating the low frequency peaks caused by standing waves,
the highs will appear to be restored and the "boomy" sound
will be gone. In many problem" rooms, the difference
with and without the M0 104 is literally night and day.

The M0 104 is designed to be used with accurate acoustic
test equipment. Response measurements in the normal
listening area are essential to correct equalization with
the M0 104. In addition. the M0 104 can be most effec-
tively adjusted by persons having knowledge and expertise
in making acoustic measurements. 00 not attempt to
change control settings or filters of the M0 104 by listening
to music or test records.

With suitable test equipment and qualified personnel,
the McIntosh M0 104 allows complete control of the listens
ing room environment at low frequencies. Not only can the
M0 104 restore the low frequency response of McIntosh
speakers and compensate for room gain, but it will also
equalize for reflected sound in the room.