McIntosh XRT29 owner manual Introduction

Figure 6

Figure 2

Figure 5

Figure 4

Figure 1

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 Poly-Switches to provide an extra measure of protection.

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.

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