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Before delving into the next sections that describe in detail the specific components that make up an audio system, let’s look at an overview of those components, how they might fit together, and options for putting together your own system.
At the very front of the playback chain are the source components. This category of product includes CD players, FM tuners, DVD players, satellite radio receivers (XM or Sirius), and turntables, to name a few. Any product that delivers a signal to the rest of your system is a source component.
The source components feed the next step in the playback chain, the control and amplification components. These components can be housed in separate chassis, called a preamplifier and a power amplifier, respectively. The preamplifier is the Grand Central Station of a hi-fi system. It takes signals from the various source components and controls which source signals (CD or radio, for example) you listen to, adjusts the volume, and performs a few other functions. A power amplifier, by contrast, is the workhorse of a hi-fi system, taking in the preamplifier’s output and boosting it to a level that can drive the loudspeakers (Fig 1).
Many quality audio systems will use an integrated amplifier, a product that com bines the functions of a preamplifier and power amplifier in one chassis. Integrated amplifiers are less expensive than a separate preamplifier and power amplifier, easier to operate, and take up less space in your home.
Another option is the receiver a product that combines a preamplifier, power amplifier, and radio tuner in one chassis. Most receivers today can tune in AM and FM signals as well as those from Xlvi or Sirius Satellite Radio subscription-based radio services. Satellite radio reception requires a separate antenna and purchase of a monthly subscription.
Receivers come in two flavors: the traditional stereo receiver that will power two loudspeakers for music listening, and the audio/video receiver (AVR) that powers a multi- channel loudspeaker array for home theater (Fig. 2). By far the more prevalent of the two is the AVR, which forms the heart of a system that will play music as well as movies. The AVR has either five or seven channels of amplification, surround-sound decoding, and the ability to control video as well as audio source components—DVD players, hard-disk video recorders such as TiVo, and satellite receivers such as DirecTV or Dish Network.
Another option for those who want their audio system to do double-duty on music and movies is the audio/video controller and multi-channel power amplifier. The A/v controller is analogous to the stereo preamplifier just described, but it also has the ability to control video source components. A multi-channel amplifier is simply a power amplifier with more than two channels of amplification, usually five or seven. The separate controller and multichannel power amplifier are (usually) higher-quality (but more expensive) alternatives to the AVR (Fig. 3).
Finally, those who want to listen to stereo and multichannel music but don’t care about film soundtracks or home theater can choose a riniltichannelpreamp4fIer. This component is identical to the stereo preamplifier we saw earlier, but has the ability to accommodate six audio channels rather than the stereo preamp’s two channels.
Which of these system configurations you choose—preamplifier and power amplifier, integrated amplifier, stereo receiver, AVR, or controller and multichannel power amplifier—is influenced by whether you want an audio system for purely music listening or for playing back film soundtracks as part of a home-theater system. Your choice will also be influenced by your budget; a stereo receiver and two speakers is generally less expensive than an A/V controller, multichannel power amplifier, and five loudspeakers plus a subwoofer.
To recap, here are your options, based on how you intend to use your audio system.
2-channel music listening only
2-channel and multichannel music, as well as home theater
The final link in the audio-system playback chain is the loudspeaker. The loud speaker converts the high-power electrical output from the power amplifier into sound. If you choose a stereo preamplifier and stereo power amplifier, you’ll need two loud speakers, left and right. For reproducing multichannel music sources and film sound tracks, you’ select a multichannel speaker system consisting of left and right speakers, as well as a center-channel speaker and surround speakers. Home-theatre systems often employ an additional speaker called a subwoofer for reproducing low bass sounds. The kit, center, and right speakers are arrayed across the front of your room, with the left and right speakers on either side of your television and the center speaker positioned above or below the TV. The surround speakers are located to the sides of or behind, the listening/viewing couch or chair.
Of these options, the one most likely to deliver the highest audio quality is the separate preamplifier and power amplifier (the reasons are discussed in Section 8). The next-best sounding choice is probably the integrated amplifier, followed by the stereo receiver. Although today’s best audio/video receivers sound better than those of a few years ago, it’s unlikely that an AVR will deliver the same quality of sound as a separate preamplifier and power amplifier, or even an integrated amplifier. Note, however, that these differences in sound quality are most apparent, and most important, for music listening, and less so when reproducing film soundtracks. If an AVR has sufficient out put power (measured in the familiar “watts per channel”) and is of reasonably good quality, it will deliver satisfying performance for the vast majority of home-theater enthusiasts. The differences lie in how these various components reproduce music; dedicated audio-only products will deliver a more engaging musical experience. (Section 4 describes the specific sonic qualities that affect how we perceive and connect with reproduced music.)
This last paragraph suggests that it’s impossible to have a no-compromise system that performs equally well on music and home theater. There’s yet one more system configuration option that combines the best of both worlds to deliver state-of-the-art music reproduction (if that’s your goal) with the best possible reproduction of film soundtracks. That system employs both a stereo preamplifier as well as an audio/video controller. Two-channel music sources feed the preamplifier, which in turns drives the power amplifier, just as in a conventional 2-channel music-only system. But A/V sources DVD player, satellite receiver, cable, digital video recorder such as TiVo) feed the controller, with the controller’s left and right outputs driving one of the preamplifier’s 2-channel inputs. The left and right channels of the film soundtrack or multichannel music source simply pass through the preamplifier to the power amplifier as though it weren’t there. It goes without saying that this is the most expensive possible configuration, but it has the benefit of keeping critical 2-channel music signals out of the A/V controller. This system configuration, shown in Fig. 4, is explained in more detail in Section 10.
Finally, there’s one more path to getting great-sounding music and terrific home-theater: completely separate systems in different rooms of your home. Each can be optimized for the specific job, although this option is by far the most expensive, and also allows audio gear to take over another room in your home.
We’ll look at each component of an audio system in Sections 5 - 11, and how to assemble and fine-tune that system in Section 12. But first, let’s look at how you go about choosing just the right combination of components for your system.