My Grado SR 80's came today. They sound good, but not as good I expected from all the rave reviews out there. However, I've also read that they require a 30-40 hour break-in time before they show their true colors. How much validity is there to this statement? I bought the SR 80's over the 60's because of the improved bass performance, but from what I'm hearing, the bass is actually lacking in some of the jazz settings, such as in the Bela Fleck & the Flecktones' albums. Will these things open up or am I losing it?