McIntosh XRT2K, Owner'S Manual, Page: 4 / 24

4
Introduction
1
COLUMN Pat. No. 4,267,405
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
For the first time, the new McIntosh XRT2K Loudspeaker
System is capable of reproducing the full dynamic range of
a symphony orchestra including pipe organ without audible
distortion. McIntosh Acoustic Engineers have refined the
line source Column Loudspeaker concept and the XRT2K
Loudspeaker System is the 6th in a generation of that pat-
ented design
1
. It provides
superior quality midrange
and high frequency sound
reproduction in a full
range system.
The High Frequency
Section utilizes a patented
Column Design
1
with mul-
tiple two inch Midrange
Inverted Titanium Dome
Drivers and three-quarter
inch Titanium Dome
Tweeters. Refer to fig-
ures 1 and 2. Since the
audio power fed to a
column is distributed
among all the drivers,
each driver does not
have to work as hard,
resulting in greater
power handling capa-
bility and a dramatic
reduction in distortion.
The Sound Waves from
the Column produce a
Cylindrical Wave Front
with a stable symmetrical horizontal sound dispersion while
minimizing undesirable floor and ceiling reflections that de-
tract from a
stable
sound im-
age. Refer
to figure 3.
In the illus-
tration, the
Loud-
speaker on
the left side
produces a Cylindrical Wave Front and the Loudspeaker on
the right side produces a conventional Spherical Wave
Front.
The Low Frequency Section of the System consists of
six 12 inch Aluminum Cone Woofers capable of long cone
excursions. The sound produced has very low levels of har-
monic dis-
tortion and
a fre-
quency re-
sponse
down to
16Hz.
They have
a large mo-
tor assem-
bly made
with High
Tempera-
ture
Neodymium magnets with inherent shielding to greatly re-
duce any external magnetic field. Refer to figure 4. The
woofer design also utilizes an aluminum shorting ring, cop-
per capped pole piece, three inch diameter voice coil and
two cone centering devices. This results in lower distortion
due to more linear magnetic flux in the voice coil gap. A
good example of this low distortion is incredible smoothness
and effortless clarity in the reproduction of the human voice.
The Crossover Networks used in the XRT2K Loud-
speaker System are designed to ensure a smooth frequency
response over the entire audible range. The Low Frequency
Crossover Network is a quasi-second order design. Refer to
figure 5. Along with the column arrangement, this network
acoustically sums to a fourth order Linkwitz-Riley low
pass. The Midrange Crossover Network is a second order
high pass and low pass design. Refer to figure 6. Acousti-
cally, the high pass sums to a fourth order Legendre and the