It's amazing what a low noise and low distortion signal will do for a pair of speakers. My Fortes never sounded so sweet. The bass is very well articulated now, it has better texture and detail. The tweeters have something to do now too, cymbals have sizzle and ring with a nice decay. Detail is amazing, I can hear background sounds on some recordings, players breathing and moving. This amp is dead quiet, absolutely black background at full volume. I think maybe the better upgrade for old Klipsch speakers isn't new crossovers or caps but using a really clean amplifier instead. Compared to the six watt tube amp I was using it is a major improvement. I think my love affair with tubes is over.