My speakers are connected to receiver, but only front left and right get sound

Set up a home theater

How to connect your speakers
In order to deliver surround sound, home theater systems require 5, 6, or even 7 speakers--and that's not even counting the subwoofer. Connecting all those speakers together can be quite a challenge, so here's a quick overview of the basics.

If you don't have an all-in-one, home-theater-in-a-box system, you'll probably need to supply your own speaker cables. There are several different types available--they vary in terms of wire size (or gauges) and termination types. Make sure you pick cable that's a good match for your speakers and receiver. And make sure they're long enough; the rear-channel cables in particular will be stretching all the way around the room.

Once you've selected your system and have all your speakers ready to set up, begin by placing each speaker at or near its intended location. Then, attach the cables to them one by one. After securely fastening one end of the cable to the speaker, connect the other end to the appropriate speaker output on the back of the A/V receiver. Be sure to connect the cable to the correctly labeled output.

For instance, the front-right speaker wire needs to go to the terminal labeled front-right. Also, make sure that each speaker connection is in phase, meaning negative to negative and positive to positive. Otherwise, your system's sound will sound out of whack. Repeat the process for every speaker in your system. Note that the subwoofer uses a coaxial-style RCA cable instead of standard speaker wire.

Once all the wires are connected, you should test the system with several DVDs and CDs, to ensure that everything is in working order.

For our first example, we used an elaborate 7.1-channel system, so it may have 1, 2, or several more speakers than your system. Some systems even employ wireless rear speakers, or virtual surround-surround modes that simulate multichannel experience from 3, 2, or even 1 speaker. And some listeners still prefer good old stereo sound from 2 speakers. No matter what type of speaker setup you prefer, however, the wiring basics remain the same.

How to position surround-sound speakers and a subwoofer
To get the best performance from a surround-sound speaker system, you must install each speaker in the correct location. There are three basic types of surround-sound speaker systems.

• The 5.1-channel system has five satellite speakers and a subwoofer.
  
  
• 6.1-channel systems have six satellites and a subwoofer.
  
  
• And 7.1-channel systems have seven satellites and a subwoofer.
  
  

Start by placing the center speaker either directly above or directly below your TV. The center speaker can be perched atop a direct-view TV or mounted on the wall. Aim the center speaker at ear level.

In most cases, the front-left and front-right speakers can be wall mounted or placed on stands. However, if your speakers have rear-panel bass ports, they should not be wall mounted. Space your front-left and front-right speakers the same distance apart as the distance between your center speaker and your listening position. Position the front-left and front-right speakers no more than two feet above or below the front-center speaker. The tweeters in the front-left and front-right speakers should be roughly at ear level relative to your seating position.

Ideally, the surround-left and surround-right speakers should be mounted on the side walls of your room, slightly behind or parallel to your listening position. If your speakers have rear-panel bass ports, place them on stands instead. If installing the speakers on the side walls isn't practical, you can mount them on the room's rear wall or place them on stands behind your listening position. The surround speakers can be installed up to two feet above the front speakers.

Also, 6.1 surround systems have a back-center speaker. You'll typically mount this on the rear wall of your room, centered behind your seating position. Position the back-center speaker no more than six feet behind the surround-left and surround-right speakers. If your speaker has a rear-panel bass port or if the rear wall is too far behind your seating position, place the back center speaker on a stand instead. The back-center speaker should be installed at the same height as the surround-left and surround-right speakers.

Instead of a single back speaker, 7.1 surround systems use a back-left and a back-right speaker. These, too, are typically mounted on the rear wall of your room. Position the back-left and back-right speakers so that each is approximately aligned with the left and right edges of your listening position. Place the back-left and back-right speakers no more than six feet behind the surround-left and surround-right speakers. If your speakers have rear-panel bass ports,or if the rear wall is too far behind your seating position, place the speakers on stands instead. Install the back-left and back-right speakers at the same height as the surround-left and surround-right speakers.

A subwoofer is the last component of a 5, 6, or 7.1 system. Because bass frequencies are nondirectional, you can place the subwoofer in various locations. You may get the best performance by installing the subwoofer in the front of the room, approximately six inches from the wall. If you want more bass, try placing the sub near a corner in the front of the room.

Connect your DVD player to your A/V receiver--digitally
To hear a movie's soundtrack in surround sound, you must first connect your DVD player to an A/V surround-sound receiver. You'll need to make what is called a multi-channel-compatible connection.

The easiest way to do this is to use a cable that carries a digital signal. There are two digital options: optical and coaxial.

An optical digital connection, also called TosLink, uses pulses of light to deliver a digital signal. According to some experts, one advantage of optical digital connections is that optical cables don't pick up noise, while lower-quality coaxial cables can. Many, but not all, DVD players have an optical output. Most A/V receivers have at least one and usually multiple optical inputs. Plug one end of the optical cable into the DVDs player's optical-out jack. Plug the other end into the receiver's optical input.

Finally, you need to tell your receiver to use the optical connection whenever you switch to the DVD input. This is called assigning the input. Information about this simple process can be found in your A/V receiver's manual.

A second option is a coaxial digital connection. This type of connection is also used for cable TV, but the connectors are different. This type of coaxial cable has an RCA connector. Coaxial cables are less expensive than optical ones. In fact, you can use any old RCA cable to make a coaxial digital connection, and you won't lose any audio quality.

Most, but not all, DVD players, have a coaxial output. Some have coaxial and optical outputs, so you get a choice. Audiophiles argue over which connection is better, but it's very hard to hear the difference. Most A/V receivers have at least one and usually multiple coaxial inputs. Plug one end of the coaxial cable into the DVD player's coaxial-out jack. Plug the other end into the receiver's coaxial input.

Finally, tell your receiver to use the coaxial connection whenever you switch to the DVD input. Again, your A/V receiver's manual will have instructions for assigning an input.