Nope, could very well be that you aren't hearing things. That things HAVE changed.
From what I know and what I think I know; speaker cables will either not change the sound at all(good cables), or, change different parts of the overall spectrum,(bad cables, but "good" if they modify the parts that you "like")
Lots of folks spend lots of money trying to get their speakers to sound like what they wish their speakers would have sounded like in the first place. And sometimes it even works!! Perhaps your old cables attenuated parts of the sound spectrum that didn't agree with you! Congratulations if it helps!!
At the very least just changing the wires will give you nice clean connections to pass the signal even better!
At any rate, it's kinda like the reason I want to get tubes for M3s in my diningroom system. I know the tubes will modify the sound cause the tubes and the speakers will chase each other round and around and change the sound in ways that I think I'll like for the "music only" system!!
