I never heard on the radio or noticed before I updgraded.
Hmmm, new speakers doing well for you I assume?

Other than your new speakers, what other upgrades have you made?
I've got a classical recording (somewhere), that you can hear papers shuffling in the background. It gives the impression the recording was done in a office setting. At one point, you can hear a pencil roll off a desk and bounce on a hard floor. Obviously it shouldn't be in the recording, but it's neat to hear things like that (but not very often).
There's several guitar tracks I've got where you can hear the guitarist breathing. A couple of them sound like they should have had a dose of nasal decongestant before they pressed [RECORD].

Hole Cole "Temptation" has a tremendous amount of "little hidden things" that can't be heard if you listen to the CD while driving. Every time I listen to this release, I hear a new "tidbit" of information I hadn't heard before.
That's all I can think of right now, but I know there's more.
Bob