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Introduction
The McIntosh HT-3 Surround Loudspeaker is specifically
optimized for sound applications. The Surround Loud-
speakers are intentionally designed to create a very diffuse
sound field. The HT-3 uses a dipolar radiation pattern to
achieve this performance. A dipole loudspeaker radiates
sound both forward and backward, with acoustic nulls lo-
cated at the vertical center of the enclosure. If a dipole
loudspeaker is placed such that the listeners are seated
within the nulls, they will hear surround sound only after it
has been randomly reflected off of the walls of the room.
The listener will perceive no specific direction for sur-
round sound. Refer to figure 1.
The HT-3 achieves this dipolar radiation via indepen-
dent forward and rearward firing 2-way systems connected
in antiphase to assure a cancellation null at right angles.
Complete mirror symmetry of forward and rearward firing
faces of the HT-3 assure a deep broadband null of all fre-
quencies for any position on the dividing plane of the sys-
tem. This includes upward and downward elevation angles
and allows the HT-3 to be mounted in a variety of heights
on the side wall (or even on the ceiling), as long as the lis-
tener is on the dividing plane between left and right halves
of the HT-3.
Varying the Sound Field
Some listeners will want a less diffuse and more direc-
tional effect from their surround loudspeakers. To them,
sound panning off screen, such as jets flying overhead, are
more important than the creation of a diffuse sound field.
This is perfectly acceptable and can be achieved by mount-
ing the HT-3 Loudspeakers so that the listener is not on the
null of the system but perhaps 20 degrees forward or back-
ward of the null. The selected volume level of the surround
speakers will also play a major role in determining
whether the surround effects are obvious or subtle.
In very large installations, more than one pair of HT-3
Surround Loudspeakers can be used. This would apply in
home installations with four or more rows of theater style
seating. For such installations install a pair of HT-3 sys-
tems in the normal way adjacent to the first seating row.
For every third or fourth row behind, install an additional
pair. Each additional pair of surround Loudspeakers should
have its polarity reversed relative to the pair immediately
in front. Polarities from the front would be normal, re-
versed, normal, reversed, etc. Change the polarities by al-
ternating the connections on each pair of Loudspeakers, in
order, behind the original pair. Refer to figure 2.
Figure 1
Figure 2
Summary of Contents for HT-3
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