My mains are JBL 120Ti (89 dB/watt/meter). My center is JBL 4410 (91 dB/watt/meter). For music, I'm going to use Sansui AU-7900 and Dynaco QD-2. For computer games, I'm going to use Yamaha RX-V663 AV receiver. I also need a DIY 5 channel speaker source selector to switch between the two...