McIntosh XRT28 User Manual

Loudspeaker System

XRT28

Owner’s Manual

McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: 607-723-3512 FAX: 607-724-0549

WARNING - TO REDUCE RISK OF

FIRE OR ELECTRICAL SHOCK, DO

NOT EXPOSE THIS EQUIPMENT TO

RAIN OR MOISTURE.

IMPORTANT SAFETY

INSTRUCTIONS!

PLEASE READ THEM BEFORE

OPERATING THIS EQUIPMENT.

NO USER-SERVICEABLE PARTS

INSIDE. REFER SERVICING TO

QUALIFIED PERSONNEL.

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this apparatus near water.

6. Clean only with a dry cloth.

7.Warning: To reduce risk of fire or electrical shock,

do not expose this equipment to rain or moisture. This unit is capable of producing high sound pressure levels. Continued exposure to high sound pressure levels can cause permanent hearing impairment or loss. User caution is advised and ear protection is recommended when playing at high volumes.

8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.

9. Protect the connection cables from being walked on or pinched particularly at the point where they exit from the apparatus.

10. Only use attachments/accessories specified by the manufacturer.

11. Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/ apparatus combination to avoid injury from tipover.

12. Disconnect this apparatus during lightning storms or when unused for long periods of time.

13. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, liquid has been spilled or objects have fallen onto the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.

14. Do not expose this equipment to dripping or splashing and ensure that no objects filled with liquids, such as vases, are placed on the equipment.

Thank Y ou

Table of Contents

Your decision to own this McIntosh XRT28 Loudspeaker System ranks you at the very top among discriminating music listeners. You now have “The Best.” The McIntosh dedication to “Quality,” is assurance that you will receive many years of musical enjoyment from this unit.

Please take a short time to read the information in this manual. We want you to be as familiar as possible with all the features and functions of your new McIntosh.

Please Take A Moment

The serial number, purchase date and McIntosh Dealer name are important to you for possible insurance claim or future service. The spaces below have been provided for you to record that information:

Serial Number: Purchase Date: Dealer Name:

T echnical Assistance

If at any time you have questions about your McIntosh product, contact your McIntosh Dealer who is familiar with your McIntosh equipment and any other brands that may be part of your system. If you or your Dealer wish additional help concerning a suspected problem, you can receive technical assistance for all McIntosh products at:

McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903 Phone: 607-723-1545 Fax: 607-723-3636

Customer Service

If it is determined that your McIntosh product is in need of repair, you can return it to your Dealer. You can also return it to the McIntosh Laboratory Service Department. For assistance on factory repair return procedure, contact the McIntosh Service Department at:

McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903 Phone: 607-723-3515 Fax: 607-723-1917

Safety Instructions............................................................. 2

Thank You and Please Take a Moment ............................. 3

T echnical Assistance and Customer Service..................... 3

Table of Contents and Important Information................... 3

Introduction ....................................................................... 4

Performance Features ........................................................ 5

Dimensions........................................................................ 6

Installation using the Column Base .................................. 8

How to Connect using a single amplifier........................ 10

How to Connect using two amplifiers............................. 12

How to Connect using three amplifiers........................... 14

Specifications .................................................................. 18

Packing Instruction.......................................................... 19

Important Information

Caution: The XRT28 Loudspeaker System weight is 139.5

pounds (63.4kg). It requires two or more persons to safely handle when moving.

1. Loudspeaker Cables of adequate size are important to ensure that there will be no significant power loss or heating. Cable size is specified in Gauge numbers or AWG (American Wire Gauge). The smaller the Gauge number, the larger the wire size:

If the Loudspeaker Cables are 25 feet (7.62m) or less, use at least 18 Gauge (AWG) wire size or larger. If the Loudspeaker Cables are 50 feet (38.1m) or less, use at least 14 Gauge (AWG) wire size or larger. If the Loudspeaker Cables are 100 feet (76.2m) or less, use at least 12 Gauge (AWG) wire size or larger. The Loudspeaker Connection Terminals can accept up to 12 Gauge (AWG) wire.

2. For additional connection information, refer to the owner’s manual(s) for any component(s) connected to the XRT28 Loudspeaker.

3. The XRT28’s built-in speaker protection incorporates five automatic resetting solid-state devices in the crossover network. One protects the tweeters, one for the midranges and three for the woofers. The protection allows a certain amount of overdrive but extended periods will trigger protection. If an obvious lack of high, mid or low frequencies is noticed, the Protection Device may have activated. These devices will automatically reset when the volume level is reduced significantly and kept low until the output of the affected Loudspeaker Element returns to normal.

4. When the XRT28 Loudspeaker System is driven by more than one amplifier, the output levels of the different amplifiers connected to the Loudspeaker System must be adjusted to achieve a proper balance between the low, midrange and high frequencies reproduced. This adjustment is best achieved through the use of audio test equipment operated by a qualified installer.

Introduction

McIntosh Acoustic Engineers have refined the line source Column Loudspeaker System concept to provide superior sound reproduction in a full range system.

The Loudspeaker System utilizes a patented Column Design1 with multiple four inch Midrange LD/HP2 Magnetic Circuit Design Drivers and one inch soft dome T weeters. Refer to

Figure 1

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

Figure 2

sound dispersion 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 Cy-

lindrical Wave Front and the Loudspeaker on the right side produces a conventional Spherical Wave Front. Refer to figure 2.

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 3. The Woofer also incorporates McIntosh’s Patented LD/HP

Magnetic Cir-

cuit Design with shielding to

LD/HP

Conventional

greatly reduce any external magnetic field, that could distort the video image on a TV/ Monitor placed next to the XRT28 Loudspeaker. Extensive investigating and testing

Figure 4

resulted in a new design concept which utilizes a pair of aluminum shorting sleeves in the magnetic circuit. Refer to figure 4. The sleeves virtually eliminate the negative influence of the fluctuating voice coil field on the permanent magnet field. This results in lower distortion due to more linear magnetic flux in the voice coil gap. Refer to figure 5. Additional benefits are less volume compression due to improved heat transfer through the sleeves and a cooler operat-

Figure 5

ing voice coil. Both measurements, as well as critical listening, reveal ten times less distortion than previous designs. 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 XRT28 Loudspeaker System is designed to ensure an even frequency

Figure 3

COLUMN Pat. No. 4,267,405 2LD/HP Pat. No. 5,151,943

Figure 6

response over the entire audible range. The Network utilizes both Second and Third Order design utilizing Capacitors and Inductors with high current capacity. Refer to figure 6. 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 utilize self resetting high current Poly-Switches to provide an extra measure of protection.

The enclosures are an important part of the XRT28 Loudspeaker System. The Loudspeaker System utilizes a massive extruded aluminum enclosure that houses the 20 four inch Midrange and 16 one inch Tweeter Drivers. Refer to figure 7. It also has multiple front to back internal braces to form a dampened rigid Column Structure. The Column’s small footprint allows for a variety of different placements in a room.

Figure 7

Introduction and Performance Features

Performance Features

Patented LD/HP Technology

•

The McIntosh Low Frequency and Midrange Loudspeaker Elements feature the patented LD/HP Magnetic Circuit Design. This design, when compared to conventional Loudspeaker Elements, reduces distortion significantly. It also increases power handling and efficiency.

Neodymium-Iron-Boron Alloy Magnets

•

The 20 four inch Midranges and 16 one inch Dome Tweeters all use this Alloy. The Neodymium-Iron-Boron Alloy has the highest flux density per unit of volume and helps to keep the Column weight to a minimum.

Shielded Magnetic Field

•

The XRT28 may be used in Home Theater Installations near a television receiver or monitor without causing the television image to degrade. McIntosh has designed special shielding around the magnetic structure of the XRT28 Loudspeaker Elements to prevent interference.

High Power Handling

•

The Loudspeaker Elements and Crossover Components of the XRT28 are all chosen for use with powerful amplifiers up to 1,200 watts.

Superior Imaging

•

Locating the Column of Tweeters between the two Columns of Midranges helps to generate a symmetrical horizontal polar response for superior imaging.

Versatile Operation and Placement

•

In additional to the regular connections, the XRT28 Loudspeaker System provides separate connections for Bi-Amplification and Tri-Amplification hookups.

Gold Plated Input Connectors

•

The XRT28 input connectors are gold plated for superior corrosion resistance and high electrical conductivity.

XRT28 Dimensions

The following dimensions can assist in determining the best location for your XRT28 Loudspeaker System.

Front View of the

XRT28

Loudspeaker System

77-

1/8

195.90cm

Side View of the

XRT28

Loudspeaker System

-1/2

11.43cm

-3/8

13.65cm

-3/4

9.53cm

Rear View of the

XRT28

Loudspeaker System

31-

3/4

80.65cm

28"

-3/8

71.12cm

20.80cm

24"

60.96cm

14.92cm

3/16

20"

50.8cm

7/8

10-

9/16

26.83cm

-15/16

10.00cm

-3/4

4.45cm

-3/8

41.59cm

-3/4

14.61cm

-3/8

41.59cm

13.65cm

+ 14 hidden pages