I would keep in mind, even though placement is very important, if you have to put a sub tight in a corner, or have your fronts at different angles close to walls with a glass sculpture in front of them, it isnt going to make them un-listenable... Its not like you are going to move a speaker 6"s and say Oh my god that sounds absolutely terrible!!! I would rather listen to the tv speakers....
Room placement can help sound a lot and with room treatments and you can make a really nice system, but these are our homes, and we need to make compromises for comfort, cost, asthetics, traffic, safety, ect...
Im sure eggcrate noise foam all over my room with the speakers pulled out another couple feet, the coffee table gone, My couch a little higher and off the back wall, and corner treatments in every corner and on every ceiling would make my theater 20-30% better...
But then I would be tripping over my front towers, wouldnt have anywhere to put my drink, and my wife would be *****ing about the foam everywhere.... So its not worth it...
Start with decent well reviewed components {if you cant audition them} and set them up as close to optimal as you can, then test any changes that need be... Although 7. may not work for everyone, I havent seen a setup that wouldnt allow for 5. ,
We just set up my sisters house with a jamo 426 5.0 and her couch is along the back wall and fit right into two side walls so no side sapace to fit the surrounds, I mounted them about 48"s off the couches arm rest {seated they are about 30" overhead}, on omni mounts with a slight pitch down and pointed at each other... and even when sat next to the wall with the bottom of the speaker inline with the top of your head, you hear the surround effect perfectly... Its not the best place for them, but I wasnt going to cut a whole in her wall to make them work and it is better than not havig them, because we tried it both ways, it sounds better with them....
