Amps, Processors and Receivers

WHILE THERE ARE MANY PARTS that make up a home theater, the two core elements are picture and sound. When it comes to sound, the surround-sound receiver, amplifier and processor are the main participants in your media system.

When planning out the audio of your home theater system you can go for separate audio components (an amplifier and pre-amp) or an integrated surround-sound receiver. Generally, going with separate components provides more flexibility, makes upgrading easier, and is suitable for very large home theater rooms. However, integrated receivers have also progressed to the point where they’re perfectly suitable for all but the most complex home theater systems.

A pre-amp (also known as a processor or pre-pro) is where all the main interconnects (the HDMI, optical and other cables) will attach. It also handles the audio/video processing by taking the signals from the source components (Blu-ray player, media streamer, etc.) and translating the digital surround-sound signals into analog signals for the amplifier. New pre-amps designed for home theater also process video, which usually means it is able to scale the output resolution to that of the display (your projector).

The amplifier takes the analog audio signals from the pre- amp and outputs them to the speakers. Subwoofers usually con- tain their own amplifiers, so separate amplification isn’t necessary.

An A/V or surround-sound receiver integrates both a processor and amplifier into one product. Putting everything under one hood can make for a neater looking equipment rack and reduces the amount of cables your home theater needs.

Beyond the basic signal handling described above, processors and receivers can do a whole lot more. Advanced components will include features for room calibration and equalization, networking capabilities, control and automation features and even media streaming. Some include integrated DACs (digital to analog converters) for playback of high-resolution audio, and others include phono-stage inputs for connecting turntables.

The key to finding the processor and receiver that’s best for you is understanding how you intend to use your home theater, how many source components you need to connect, how many speakers you plan to use, and of course how big the room is for amplification purposes.

At a minimum, you need processing capabilities to handle all the common surround-sound formats, including Dolby Digital Plus, Dolby TrueHD and DTS-HD Master Audio. A format that’s just hitting the home theater market is called Dolby Atmos. Dolby Atmos, unlike other surround formats, isn’t defined by the number of channels (such as 5.1, 7.1). Instead, the audio experience is de- fined around sound objects. Within a soundtrack a given sound is treated like an object that can change position (which they often do, such as a plane flying across the sky). An Atmos-compatible processor will fit an object’s sound trajectory to the number of speakers in your room to create the most accurate sound possible.

Many receivers have more audio channels built in than what you might intend using in the home theater. These types of receivers allow you to apply the additional audio channels to other rooms. For example, if you have a 9.2 receiver, but only plan to use 7.1 channels in your media room, you can wire another room for stereo sound as a completely separate zone with the leftover audio channels.