![](/images/new-backgrounds/1016229/162297x1.webp)
Introduction
McIntosh Acoustic Engineers have refined the line source Column Loudspeaker concept to provide superior quality midrange and high frequency sound reproduction.
The High Fre- quency Section utilizes a patented Column Design1 with multiple four inch Midrange LD/HP2 Magnetic Circuit Design Drivers and one inch soft dome
Tweeters. Refer to figure 1. 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 capability and a dramatic reduction in distortion. The Sound Waves from the Column produce a Cylindrical Wave Front with a stable symmetrical horizontal sound dispersion to minimize undesirable floor and ceiling re- flections
that could detract from
astable sound im- age. Refer to figure 2. 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 conven- tional Spherical Wave Front.
The Midrange Drivers incorporate McIntosh’s Patented
LD/HP2 Magnetic Circuit Design with shielding to greatly | ||
reduce any external mag- |
| |
netic field. Extensive inves- | LD/HP | |
| ||
tigating and testing resulted | Conventional | |
in a new design concept | ||
| ||
which utilizes a pair of alu- |
| |
minum shorting sleeves in |
| |
the magnetic circuit. Refer |
| |
to figure 3. The sleeves vir- |
| |
tually eliminate the nega- |
| |
tive influence of the fluctu- |
| |
ating voice coil field on the | Figure 3 | |
permanent magnet field. |
|
This results in lower distortion due to more linear mag-
1COLUMN Pat. No. 4,267,405 | 2LD/HP Pat. No. 5,151,943 |
netic flux in the voice coil gap. Refer to figure 4. Addi- tional benefits are less volume com-
pression due to im-
proved heat transfer through the sleeves and a cooler operat-
ing voice coil. Both measurements, as
well as critical lis- tening, reveal ten times less distortion
than previous de-
signs. A good example of this low distortion is incredible smoothness and clarity in the reproduction of the human voice.
The Crossover Network used in the XRT29 Loud- speaker System is designed to ensure an even frequency response over its
audible range. The Crossover Network utilizes both Second and Third Order Crossover Designs. Refer to figure 5. It also uses Capacitors and Inductors with high current capac- ity. The Capacitors used include low loss (ESR) Polypro- pylene and Mylar types. The Cross- over Network uti- lize self resetting
high current
The enclosure is an important part of the XRT29 Loud- speaker System. The High Frequency Column utilizes a massive extruded aluminum enclosure that houses the 30 four inch Midrange and 25 one inch Tweeter Drivers. Re- fer to figure 6. It
also has multiple front to back in- ternal braces to form a dampened rigid Column Structure. The
Column’s small footprint allows for a variety of different placements in a room.
4