Several friends asked me about AV Receiver can do. I said I would answer in my blog. AV Receiver is a main part of home theater system. AV receiver control all signal processing in home theater. There are two kinds of signal in home theater, audio signal and video signal. AV receiver process both signals to produce theater or entertainment atmosphere.

Radio reception

Receivers usually have a built in tuner for AM and FM radio reception. Satellite radio tuners are also found in many modern receivers, allowing reception with just an external antenna (and a satellite radio subscription, if necessary).

Dolby and DTS

When Dolby Labs and DTS introduced technologies to add a rear center surround channel, these technologies found their way into AV Receivers. Receivers with six amplifiers (known as 6.1 receivers,) will typically have both Dolby and DTS’s technologies. These are Dolby Digital EX and DTS ES.

Dolby introduced Dolby Pro Logic II to allow stereo sources to play back as if they were encoded in surround sound. DTS introduced a similar technology, NEO:6. These decoders have become common on most current receivers.

As the number of playback channels were increased on receivers, other decoders have been added to some receivers. For example, Dolby Labs created Dolby Pro Logic IIx to take advantage of receivers with more than five channels of playback.

DSP effects

Most receivers offer specialized Digital Signal Processors (DSP) made for handling various presets and audio effects. Some may offer simple equalizers and balance adjustments to complex DSP audio field simulations such as “Hall”, “Arena”, “Opera”, etc. that simulate the audio being played in the places through use of surround sound and echo effects.

Amplification

Stereo receivers have two channel of amplification, while AV receivers may have more than 2. The standard for AV receivers is five channels of amplification. These are usually referred to as 5.1 receivers. This provides for a left, right, center, left surround and right surround speaker to be powered by the receiver. 7.1 receivers provide for two additional surround channels, left rear surround, and right rear surround. The ‘.1′ refers to the LFE (low frequency effects) channel the signal of which is usually sent to an amplified subwoofer unit. 5.1 and 7.1 receivers don’t usually provide amplification for this channel. Instead, they provide a line level output.