AV Receiver - Heart Of Your Home Theater

Audio Video Receivers are the heart of any home theater systems. They are basically amplifiers that can amplify sound from various sources. Most AV receivers have multiple amplifiers for best results. They can take input from various sources such as Blue Ray devices, DVD players, gaming consoles such as Ps3, TV boxes etc. They can route the video you want to your TV and process, amplify and send the audio to your speakers.
Difference Between Stereo and AV receivers
Stereos can send sound output to only two channels namely left and right and sometimes to the sub-woofer. Audio video receivers, also known sometimes by the name of 5.1 receiver, can send the audio output to five or more speakers. More advanced receivers can do up to 9 speakers.
The main functions of AV receivers are briefly discussed below:
Decoders They are known to have ability to decode sound i.e. process the sound. For example, a they can receive a 2 channel sound but send it to 5 different channels to produce surround effect.
DSP effect They can also manipulate sound to produce different effects, such as equalization and field simulations such as "concert", "hall" etc.
Video upconvertion This is usually called upconvertion or transcoding. They can convert videos from one format to the other. For example, a AV receiver can convert a 480 pixels video(480 lines per frame) to 720 pixels video(720 lines per frame and also change a component video to s-video. For people with incompatible devices, a AV receiver can be very beneficial.

Amplification Last but not the least, amplification. Audio video receivers amply different channels of sound that can be send to individual speakers. a 5.1 amplifier can send sound to a center speaker, left front and right front speaker, rear left and rear right speakers. All of these channels are amplified individually. High quality receiver offers very less distortion of sound offering as clear sound as possible. Thus while buying a receiver you should always consider its distortion level. Distortion less than.1% are really unnoticeable so try not to buy the ones with distortion level more than 0.1%. Louder the sound needed more amplification is needed, meaning more power is used by the amplifier.