An audio/video receiver (AVR) is considered the center of a home theater system. It is this device that receives signals from the input devices you decide to use, such as VCRs, DVD players, or satellite dishes. The AVR's job is incredibly important as it interprets and transmits the necessary signals to your television and audio equipment.

AVRs can be costly. Purchasing a quality AVR brand new could cost hundreds of dollars. To reduce costs, many choose to purchase used AVRs instead.

Much like purchasing a unit brand new, buying a used AVR requires the consideration of a few factors. The first thing to consider and look for in a unit is connectivity. Think about what you plan to hook up to your AVR, now and in the future. It is rarely a mistake to look for a used AVR with multiple inputs. If you are into high-definition television (HDTV), you may find it beneficial to look for digital video input (DVI) or high-definition multimedia interface (HDMI) connections. Likewise, you may want USB connectivity if you plan to enjoy an MP3 player with your system or a FireWire port for use with a DVD-audio player.

If you want to set your system up to allow you to enjoy audio in more than one room, search for a used AVR that works with remote zones. There are actually AVRs available that allow the user to listen to music in one room, while others in the same house enjoy a movie, complete with sound, in another room. By purchasing a used AVR that has amplifier channels set up for multiple zones, you can avoid wasting money on another AVR for a second set of speakers.