Actually, the si versions are much better.The tweeter and mids are where the improvement occured. A lot of fussing re. placement pays off.If you have the manual, their recommendations are spot on. 10years ago when a friend and I had similar (he had plain 1s;I had 3sis)we both had almost the same gear and ics. He was always jealous. Your old style can not be upgraded to si status.
