Hi Semion, we have same questions when I first setup my HT and thanks to this forum and I was able to setup my HT properly. So I am just returning the favor...I want to share it to you...
First start on this link (c/o chessero)--> http://www.soundandvisionmag.com/SoundAndVision/Article01/Features/SetupSpeakers0501/SetupSpeakers0501p01.html
Next is to answer some of your question:
for surround speaker, the standard height must be 2 to 3 feet above from your listening position, but like all the people who uses QSx series as surround in this forum, it doesn;t matter where you place the surround due to the quadpolar design of the speaker.
For Receiver speaker settings on, if you have a Sub, set all your speakers to small (front, center, surround). So that any sounds below 80-90Hz (THX i believe 80Hz) will go to your Sub.
Sub connection: Use your receiver Sub pre-out (RCA connection) and connect it to your Sub Low level RCA input (either Left or Right doesn;t matter). You only need the two channel on your sub if you have 2 subs (L & R), and using a Y-cable.
Hope I was able to help you.
