Place on-screen dialogue in the center front speaker. This speaker is aligned most directly with the audience and should be outputting all of your primary sound. Because you want the audience to focus on what is being said between actors in a scene, their sound is of utmost importance.
Place the film’s score in the left front and right front speakers. On-screen sound that is not major dialogue should also be directed to these speakers. On-screen sound refers to any sound being produced by a source that is visible in a particular shot. If a car has to stop abruptly towards the left of the screen, pan the screeching sound of the brakes towards the left front speaker. Panning is accomplished by increasing the volume in a particular speaker to create the illusion that the source of the sound is coming from that direction.
Place ambient sound in the left surround and right surround speakers. Ambient sound refers to background or atmospheric sound, such as the din of conversations in a packed restaurant or rain hitting the ground. Sound effects that take place off-screen should also be placed in the left surround and right surround speakers. For example, if the car mentioned above is intentionally left out of the shot, but a character in the shot is reacting to the abrupt stop, the sound of the screeching brakes should be placed in the left surround speaker.
Pan sounds from moving objects from one speaker to another. This can often be the most challenging part of mixing surround sound. For example, if the car above begins braking off-screen, but ends up stopping two inches from the main character on-screen towards the right, you should pan the screeching sound from the left surround to the left front to the right front. You do this by simultaneously decreasing the volume of that sound in one speaker and increasing it in the other as it travels.