To achieve the best sound quality in a multi-channel home theater setup, proper speaker placement is crucial. Place the center channel speaker directly above or below your TV or screen, ensuring it's aligned with the seating position. Front left and right speakers should be placed at an angle of 22 to 30 degrees from the center listening position. Surround speakers should be 90 to 110 degrees apart, while the rear surround speakers (if present) should be located at 135 to 150 degrees. For Atmos or DTS setups, height or ceiling speakers should be positioned above the listening area.