A friend of mine has PSB 1000 floorstanding speakers he bought about 5-6 years ago. He is looking into expanding his stereo setup into HT, so he is asking what center channel speaker would be a good match. Also, there appears to be a very small dent in the tweeter, but he didn't hear it and didn't know the dent existed until he removed the grill. So, first of all -- what would be a good center/surround speaker to match for a 5.1 setup? Second, does anybody know if it's easy to replace the tweeter and what the replacement can cost/where to buy? And he can't find any specs, so maybe somebody knows what the tweeter type/size is? And the last but not least -- what sub would be a good option? Any info would be appreciated.