Originally Posted by RCA Dimensia
So how does it sound good anywhere in the theater, if the middle sounds good how does the corner not sound bad and how does the front sound good, too.
Theatrical mixes rarely carry discrete, localized audio designed to tightly synchronize with sound from the front. If there's forest ambience or water dripping or distant gunfire in the surrounds, it doesn't really matter if it reaches the front rows a tiny bit later than the back rows; it's not really synchronized with the front channels anyway.
Most of the time, surround mixes on home video function similarly. But sometimes surround systems are used for things like multichannel music, where timing and balance among the speakers is more critical, and so those settings in the setup menu become more critical.
In a home theater, using bipole/dipole speakers is a common method of compensating for how small the room usually is. You prevent the problem of having someone so close to a surround speaker that they can't hear the other ones by using speakers that "smear" the sound along the side or back walls. Using multiple direct radiators, or aiming direct radiators away from the listeners, can have a similar effect.
So can going with 7.1, which when using 5.1 source material and a processor with Dolby Pro Logic IIx will spread the surround information amongst the four surround and rear surround speakers.
This is usually satisfactory for movies with their ambient surround mixes, but of course the better it works for movies, the poorer the results with discrete multichannel music where often the five full-range channels are treated equally in the mix.