I can try to answer your questing regarding the Zoro's vs the JVC S500, all IMO of course. First of all, the Zoro's are much more efficient and thereby they are much louder at a given volume compared to the S500. This factor gave me a slight volume matching issue when I compared them directly.
Starting at the bottom. The bass level of the S500 is much more pronounced than what's coming from the Zoro's that I feel presents almost the perfect amount of bass.
The midrange is pushed further back on the S500 when compared to the Zoro's, but they do sound very clean and they have somewhat of an addicting presentation in this particular area. But the major problem to me at least was that I constantly wished that there was more of it! In particular when I focus on vocals where I felt that the width of the vocals is only around 2-3 inches wide out of around 10 inches of soundstage, if this makes any sense? If I could get one inch or more added to the "width" of vocals then I believe that they could sound really great. Maybe bringing down the bass a notch using EQ could help, but I haven't tried.
The treble of the S500 are not on the same level as the bass, so I feel the balance is skewed towards a stronger bass presentation than treble presentation and when I compared them to the Zoro's these sounds to me to have a better balance. I also noticed one thing when listening to the S500. On certain tracks and/or albums I experienced a veil. I'm yet not quite sure what's causing it, but I most certainly heard it. Listening to the same tracks with either the Zoro's or V-80, then the veil wasn't there.
Anyway, I believe the S500 in particular sounds at it's best when used when listening to trance/electronica/dubstep, but I did find the Zoro's sound signature/presentation to be more versatile and they basically sounds great with almost any other type of music that I just mentioned.
The price of the S500 are hard to beat and maybe the best portable headphone with a V-shaped signature that I have heard below $100.
But I do prefer the Zoro's much better due to my own personal preferences which favor a more flatter balance and more forward mids.
Now the funny part actually is that I don't have Zoro's anymore ;-(( Our oldest teenager, just left for college and yesterday I let him pick out one this trio CAL's/S500/Zoro's to take with him so he had a decent portable headphone to use in his room. He's majoring in music, vocals, so his ear for music I would very much assume are very good, otherwise I do believe that his college wasted almost a full scholarship on him!
He was not acquainted with the terminology used on HF to describe how headphones sound or he was not aware of which one of the three headphones I liked the most, he's also not the typical teenager who wears Beats and as a matter of fact he believes it's ridiculous that his peers are wearing headphones outside etc. so the design factor was pretty much ruled out as a factor in his choice as well.
So he ended up choosing the Zoro after comparing the three headphones for an hour or so, using an iPhone as his source and with four songs that he had chosen and that represented the music he prefers. His conclusion was that the Zoro's was the most natural sounding to him. I found this very interesting! Unfortunately for me, he took my Zoro's!
Edited by Jupiterknight - 8/18/12 at 9:46pm