I have a Pioneer VSX20-11 and 5 8ohm speakers - JM Labs Chorus 715. I want to add 2 more speakers for the extended surround channels. Can the Pioneer cope with a 4ohm load? Will any amp capable of driving 4 and 8ohm loads be able to reach the same volume or SPL with all 7 speakers or will some channels seem to run out of steam? Are integrated AV amps generally less able to deal with tricky loads? I had been considering adding a Dynaudio Audience 82 to the front but some of the threads on this forum have questioned the Pioneers' ability to drive 4ohm speakers. Is it best to have uniform impedance all round? I have been thinking of using QED Silver Anniversary cable for the front 3 speakers. What cable would be recommended for the 4 rears - the Silver Anniversary is a little expensive as the distance is 10-11m? Any advice appreciated.