Introduction
McIntosh Acoustic Engineers have further refined the con- cept of line source column in the XRT1K Loudspeaker to provide superior sound reproduction in a full range system. It uses the same acoustic technology found in the famous XRT2K Column Loudspeakers. The technology has been refined over the years and is now the 6th generation of the design and provides superior
quality sound reproduction in a full range system.
The High Frequency Sec- tion utilizes a patented Column Design1 with multiple three- quarter inch Titanium Dome Tweeters and two inch Midrange Inverted Titanium Dome Driv- ers. Refer to figures 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 capability and a dramatic reduction in distortion. The Sound Waves from the Column produce a Cylindrical Wave Front with a stable symmet- rical horizontal
sound disper- sion to minimize undesirable floor and ceiling reflections that could detract from a stable sound image. In
the illustration the Loudspeaker on the left side produces a Cylindrical Wave Front and the Loudspeaker on the right side produces a conventional Spherical Wave Front. Refer to figure 3.
The Low Frequency Section of the System consists of two 10 inch Woofers. They have a large magnet assembly and long cone excursions with very low levels of harmonic distortion and frequency response down to 16Hz. Refer to figure 4. The Woofer also incorporates McIntosh’s Pat- ented LD/HP2 Magnetic Circuit Design. Finite Element Analysis and testing resulted in a design concept which utilizes a pair of aluminum shorting sleeves in the magnet- ic circuit. Refer to figure 5. The sleeves virtually elimi-
1COLUMN Pat. No. 4,267,405 | 2LD/HP Pat. No 5,151,943 |
nate the negative |
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influence of the |
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fluctuating voice |
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coil field on the |
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permanent magnet |
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field. This results |
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in lower distor- |
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tion due to more |
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linear magnetic |
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flux in the voice |
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coil gap. Refer to |
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figure 6. Ad- |
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ditional benefits |
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are less volume |
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compression due |
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to improved heat |
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transfer through |
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the sleeves and a |
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cooler operating |
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voice coil. Both |
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measurements, |
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as well as critical |
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| Figure 4 | |||
listening, reveal | ||||
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ten times less distortion than |
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LD/HP | ||||
previous designs. A good |
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example of this low distortion | Conventional | |||
is incredible smoothness and |
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clarity in the reproduction of |
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the human voice. |
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The Crossover Network |
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used in the XRT1K Loud- |
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speaker System is designed |
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Figure 5 | ||||
to ensure an even frequency | ||||
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response over |
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the entire au- |
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dible range. The |
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Network utilizes |
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both Second |
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and Third Order |
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design utilizing |
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Capacitors and |
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Inductors with |
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high current |
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capacity. Refer | ||||
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to figures 7, 8 and 9. There are two different types of low loss (DCR) Inductors in the network, each one chosen not to exhibit any core saturation even at high power levels.
This prevents the addition of distortion to the music at any frequency. The Capacitors used include low loss (ESR) Polypropylene and Mylar types. The Network also utilizes
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