Side speakers?

At this stage of my system i agree with slappy. At one time I had a 10 channel system with 3 sets of Polk SRT s two extra SRT sub enclosures and 4 top of the line Polk bipoles ; two in the very back spaced 4 feet apart and two above my head for height illusion . Each speaker had an Adcom 555 11 in mono for 600 watts . The Lexicon MC 12 ran it all. For theatre it was a visceral experience i will not forget. I now focus on a natural , effortless musical mulltichannel environment and have found 5.1 works best , for me at least . The meridian 861 was a real eye opener and i discovered a simpler more rewarding path.

Maybe its a case of semantics here but here is my understanding. In the post Dolby surround era the 5.1 means mains , center , and surrounds { commonly refered to as rears }. The .1 signal sends the lfe to a dedicated sub. Im not getting into THX specs .The most respected theory was postulated by the team at Widescreen headed by Gary Reber and challenged the THX camp and has in reality been adopted by about everyone now. All monopole { preferably all speakers identical or at least the same in timbral character } , equidistant from the sweetspot using equal amplification and speaker cable legnths. The info was discrete. The coming of 7.1 refered to side "surround " speakers placed directly to the sides of the listener . Again equidistant if possible , if not , the delay feature could compensate somewhat. This configuration was at the heart of the lexicon processors and they led the way with some exciting white papers backing their position that a side image was a necessity.They still make some of the top theatre processors on the market . This signal sent to the " sides " was not discrete but matrixed. Enter DD EX and DTS ES . Theory was that the back of the soundstage needed filling and processors as well as software were trickling in a discrete single back channel that was to be placed at the same tweeter level as the others , equidistant once again with equal amplification and ideally be again , of the exact same model as the others. Ideal world indeed . I can not comment on what specifically commercial movie theatres do .