Hi friends, I'm about to replace my surround speakers. I need smaller and with small depth. After moving to new house : 1) I can't use the side walls to place 'em 2) Rear wall the only option 3) Rear wall is right behind listening position (couch). What speakers will work better? Conventional or Bipolars? How high do I have to place 'em? Budget : $250 ( Eltax HT-2, Mission m7ds, Tannoy mXR ) My system: Yamaha A5 driving B&W CC3 (central) Mission 760 (rear) REL Q150E (sub) Musical Fidelity Rainbow preamp & 2xTyphoon monoblocks driving B&W 805 matrix (front). (Yamaha A5 main preout connected to MF Rainbow).