So here are my more elaborate impressions of the FSC, comparing them to the Sony 7520 and from memory the B&W P7.
Overall the FSC has a slightly warm presentation, certainly not bright. I feel like a bit of burn in (it hasn't been much though, forgot to leave them overnight) has improved the sound a bit, almost like the drivers have loosened up a bit.
Anyway the bass is well controlled and present. In terms of quantity not nearly as much as the P7, in terms of quality it's quite good though. But not as good as the 7520, which is very tight and well controlled and I'd say has the perfect quantity of bass. On some songs the P7 overdid it a bit, in retrospect. The sub-bass of the FSC is actually quite nice, you can definitely hear and 'feel' it, perhaps not as much quantity as the P7, but certainly of similar quality. The 7520 also performs nicely on the sub-bass, but perhaps slightly less quantity than the FSC. The sub-bass is something I didn't hear on the first spin I gave the FSC, but now I do hear it so in that sense I'm somewhat relieved (my first reaction was: really? 300 bucks and no sub-bass? really?)
In terms of soundstage it can't beat the 7520 or the P7. The instrument separation is fairly good though, you can hear all the individual instruments and it doesn't seem to jumble them all together. Would have been nice if it had a little bit more highrange sparkle. But yeah, inspite of pretty good instrument separation, they are place much closer together than the 7520 and P7 do. And in that way I definitely prefer the 7520 and P7 over the FSC.
The midrange is slightly recessed, but otherwise well defined and smooth sounding. Vocals sound pretty good, but again a bit recessed against the rest of the spectrum, but still very smooth and good and you can hear most of the subtleties in the vocals. I guess this is a matter of personal preference. I guess I like it a bit less recessed than how it's presented on the FSC. I think the 7520 strikes a nice balance and the P7 is good enough. The KEF M500 was a bit too forward in that respect. Piano's and guitars are nicely rendered, although it's missing that last bit of detail to make it truly stand out.
The treble is quite present and so far hasn't gotten sibilant with vocals. A little bit more sparkle would have made it even nicer and would have improved the sense of detail. A song I use to test this is the song Cicadas by Cowboy Junkies. You hear all the cicadas in the background and in headphones that miss that last bit of sparkle you barely hear the cicadas. Well on the FSC you can hear them pretty good, but the 7520 does a better job of it (but from memory, the Philips L2 which I had for a short while performed superbly in this area). I'd say the treble is a bit better done than on the P7, which already was quite good. It just can't beat the 7520 which I'd say performs well throughout the whole frequency range.
In terms of detail, not as good as the 7520. And I suspect the P7 is not as good as the 7520 either in that respect. The 7520 is an extremely detailed headphone, but I guess it was designed that way since it's marketed as a professional studio headphone (it also can't be found on Sony's consumer website, only on their Pro website).
So overall, my conclusion is that it's a pretty good headphone. The sound is fairly balanced, although the mids are slightly recessed to my ears and compared to the other headphones I've heard. Overall it's a pretty fun headphone to listen to and the warmish balanced presentation will please a lot of ears I suspect. And the bass is certainly not overdone, but is there when the music calls for it and there is enough highrange sparkle to please most ears. Could a few things be better though? yup! And I think the P7 sounds better if I remember correctly, and I'm sure the 7520 does. It's a world of difference, no matter how you put it, the FSC sounds a bit veiled compared to the 7520 (but the 7520 is a very clear, open and detailed headphone so I suspect a lot of headphones will sound veiled by comparison. I think the P7 would also sound veiled compared to the 7520, but would need to an A/B to confirm).
Otherwise, did I already say I hate the comfort? Seriously, try these before you buy because I suspect they will be uncomfortable for many people. I have very average ears (they're 65mm long, and the average earsize for males is 64mm). These could have been headphones I could have ended up liking, but I can't bear listening to them for more than 5 minutes straight because of the extreme discomfort I experience. Switching back to the 7520 feels like heaven by comparison.
The build qualty is quite good and there is plenty of soft leather used in the construction. It feels very sturdy. The earcups also fold inwards, so they can be made significantly smaller for putting in your travelbag. Otherwise it's a combination of metal and plastic. So, that's that, now they're going back in the box and will ship 'm back tomorrow. Unless someone wants to buy them from me at full retail price (€ 299)
Now, here are some pictures