Hi Evergrey, thanks for the tips. I tried replacing the centre speaker with one of the rear 601 surrounds, which also sounded quiet. I'm not sure how much can be wrong with the cable, but it's either the cable or the receiver. The cable has four terminations at the speaker end. I have tried switching red for red and black for black. I haven't tried switching entirely to test. I'm hoping it's not the amp. I could try hooking the LCR600 speaker to the left or right front channel to test that. I'll tinker this weekend.
The same problem exists with my PS3 as source.
The same problem exists with my PS3 as source.