Introduction to Home Theater

The AVR 254 may be the first multichannel surround sound receiver you have owned. Although it has more connections and features than 2-channel receivers, many of the principles are similar and the new concepts are easy to understand. This introductory section will help you to familiarize yourself with the basic concepts, which will make setup and operation smoother.

If you are already familiar with home theater, you may skip this section and proceed to the Connections section on page 18.

Typical Home Theater System

A home theater typically includes an audio/video receiver, which controls the system; a DVD player; a source component for television broadcasts, which may be a cable box, a satellite dish receiver, an HDTV tuner or simply an antenna connected to the TV; a video display (television); and loudspeakers.

All of these components are connected using various types of cables for audio and video signals.

Multichannel Audio

The main benefit of a home theater system is that several loudspeakers are used in various locations around the room to produce “surround sound.” Surround sound immerses you in the musical or film presentation for increased realism.

The AVR 254 may have up to seven speakers connected directly to it (plus a subwoofer). Each main speaker is powered by its own amplifier channel inside the receiver. When more than two speakers are used, it is called a multichannel system.

•Front Left and Right – The main speakers are used the same way as in a 2-channel system. However, you may notice that in many surround modes, these speakers are used more for ambient sound while the main action, especially dialogue, is moved to the center speaker.

•Center – The center speaker is usually placed above or below the video screen, and is used mostly for dialogue in movies and television programs. This placement allows the dialogue to originate near the actors’ faces, for a more natural sound.

•Surround Left and Right – The surround speakers are used to improve directionality of ambient sounds. In addition, by using more loudspeakers in the system, more dynamic soundtracks may be played without risk of overloading any one speaker.

•Surround Back Left and Right – Additional surround speakers may be placed behind the listening position, improving the precision with which ambient sounds may be placed and allowing for more realistic-sounding pans. By using more speakers in the system, the same sound levels may be attained with less burden placed on any individual speaker.

The surround back speakers may also be used with specialized surround modes that are designed for use with 7.1-channel systems, such as Dolby Digital EX, Dolby Digital Plus, Dolby TrueHD, DTS-ES (Discrete and Matrix), DTS-HD High Resolution Audio, DTS-HD Master Audio and Logic 7 (7.1 modes). However, the surround back speakers

are optional. In fact, the AVR 254 enables you to set up a 5.1-channel system in your main listening area, and reassign the surround back channels for use with a multizone system, in which you use the surround back channels to power a pair of loudspeakers located in another room.

Many people expect the surround speakers to play as loudly as the front speakers. Although all of the speakers in the system will be calibrated to sound equally loud at the listening position, most artists use the surround speakers for ambient effects only, and they program their materials to steer very little sound to these speakers.

•Subwoofer – A subwoofer is a special-purpose speaker designed to play only the lowest frequencies (the bass). It may be used to augment smaller, limited-range satellite speakers used for the other channels. In addition, many digital-format programs, such as movies recorded in Dolby Digital and other digital formats, may contain a special low-frequency effects (LFE) channel which is directed only to the subwoofer. The LFE channel packs the punch of a rumbling train or airplane, or the power of an explosion, adding realism and excitement to your home theater. Many people use two subwoofers, placed on the left and right sides of the room, for additional power and even distribution of the sound.

Surround Modes

There are different theories as to the best way to present surround sound and to distribute soundtrack information among the various speakers. A variety of algorithms have been developed in an effort to accurately reproduce the way we hear sounds in the real world. The result is a rich variety of surround mode options. Some modes are selected automatically, depending on the signal being received from the source. In many cases, you may select a surround mode manually.

Several companies have taken surround sound in slightly differing directions. It is helpful to group the numerous surround modes:

•Dolby Laboratories, Inc. Modes – Dolby TrueHD, Dolby Digital Plus, Dolby Digital, Dolby Digital EX, Dolby Pro Logic II and IIx, Dolby Virtual Speaker, Dolby Headphone

•DTS Modes – DTS-HD, DTS-HD Master Audio, DTS, DTS-ES (Discrete and Matrix), DTS Neo:6, DTS 96/24

•Harman International (the Harman Kardon parent company) – Logic 7

•Stereo Modes – Generic modes that expand upon conventional 2-channel stereo, including 5- and 7-Channel Stereo

Table A12 in the appendix contains detailed explanations of the differences between the various mode groups, and the mode options available within each group. Digital modes, such as Dolby Digital and DTS, are only available with specially encoded programs, such as HDTV, DVDs and digital cable or satellite television. Other modes may be used with various digital and analog signals to create a different surround presentation, or to use a different number of speakers. Surround mode selection depends upon the number of speakers in your system, the materials you are watching or listening to, and your personal tastes. Feel free to experiment.