Introduction

Figure 3

Figure 1

Figure 2

Figure 4

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 design1. It provides

superior quality midrange and high frequency sound reproduction in a full range system.

The High Frequency Section utilizes a patented Column Design1 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.

1COLUMN Pat. No. 4,267,405

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

afre- 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

Figure 5

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