After purchasing a pair of CAL!s for my desktop PC, I wanted to obtain a portable set of cans as well (CAL!s are way too delicate). After some searching I discovered the JVC HA-S500, which has received many positive reviews from fellow Head-Fiers; I liked what I read in their multi-thousand post appreciation thread, so I decided to pull the trigger. Honestly, I'm not hearing what all of the forum hype is about.
Compared to the CAL!s, the JVC's bass overshadows its mids, and the upper mid-range / lower treble is almost nonexistent. Sure, the bass hits harder and has a bit more texture than the CAL!s, but the mids are just so veiled...I hope that the burn-in process will bring the mids a few steps forward, else I will use the 5-band equalizer on my Sansa.
I will note that the JVCs are VERY easy to drive...to get to my listening levels, they require roughly half the power that the CAL!s do.
I am no professional audiophile, so the S500s may actually have the more neutral sound signature...but not to my ears, not by far. That said, I look forward to reading Joker's opinion of the set.
And Joker, thank you for the time and effort you have put into this shootout / guide...I refer to it almost daily, and link it to anyone who is looking for headphone-purchasing guidance.