Amplifiers are among the most complex pieces of home audio equipment, and you may be wondering exactly what an amp adds to your system. Not all home theater systems require amplifiers, but others can most certainly benefit from them. An amplifier, in essence, increases the amount of current in an audio signal being relayed to your speakers, thus "amplifying" it. Basically, amplifiers give you the ability to make sound playback louder without turning up your speakers.

When Is It a Good Idea to Get a Home Audio Amp?

The key thing to remember is that amplifiers do much more than add volume; they also give you a boosted measure of control over your system's overall performance. Because an amplifier increases the current in an audio signal, fine variations are more easily reproduced in your speakers. Thus, if you add an amplifier to your system, you will hear more detail in the playback and enjoy generally improved sound quality. All you need to do is listen to your audio at the same volume level with a home theater amplifier and without one to realize what a difference an amp can make.

Generally, you can benefit from a home cinema amplifier if you want to improve the richness and detail produced by the system, or if you want boosted volume capabilities. Generally speaking, you're better off choosing a wired amplifier than a portable amplifier whenever possible. Portable amplifiers generally deliver inferior sound quality for a comparable price; the only time you should choose a portable amp is if you have a real need to move the amplifier from place to place.

When looking at amplifiers, you need to consider a wide range of performance capabilities, including:

• The number of channels; make sure this is compatible with your intended application
• Output power; this typically varies, depending on the number of ohms being used in playback, but larger power outputs signal superior performance and flexibility
• Frequency response -- 20 to 20,000 Hertz is ideal
• Signal to noise ratio -- lower is better

Amplifiers are highly recommended for home theater systems of all sorts, and for music lovers who want to enjoy their favorite music with enhanced texture, nuance and detail.