Intel Mac :: 21.5" Speaker Damage Due To Feedback?

I transferred some Garageband files from my old iMac to my new one. I opened up a song to listen (it had been about 4 months) to it and I forgot that the monitor was on. I am assuming that feedback protection was on, as there was nasty and extremely loud feedback for about 2.5 seconds before the "feedback detected" message popped up. The volume on the Mac was at between 60 and 75 percent up. 

I am slightly concerned about damage to the speakers. Everything sounds ok, but I noticed a slight tinny, feedback sound (on the highs) on certain songs. It could have easily just been part of the songs I listened to, as some were self-recordings of not great quality. Others (acoustic) did not seem to have that problem. 

I understand feedback can be dangerous, but the fact that Garageband caught it fairly quickly, there was no pop or buzz, and I still have working speakers makes me feel a bit better. In short: am I just being paranoid, or does this warrant a trip to the Apple Store to have them take a look?

Info:
iMac, Mac OS X (10.7.3)