I did listen to some classical, mainly two Brahms piano concertos, a modern digital recording, and I found the CD780s to be absolutely breathtaking for those recordings. I didn't find it screechy, but I think it will depend on the recording, particularly on how brightly they recorded the violins, which can vary quite a bit.
I've done a lot more listening to my CD780s. Truth be told, they are bright. Not as bright as V6s or D66 eggos. In the treble, they're very close to the brightness of the HD280s, but the mids of the CD780s are brighter than the HD280 mids. I think it's an area where some people like it and some people won't -- a matter of taste. For me they have a breathtaking realism that is unique among the headphones that I have. But I must concede, for the benefit of people who would think about buying them at full price, that they are on the bright side of neutral.
For the rock music I've listened to on the CD780s, I found them exuberant and engaging -- again, it's going to be whether you enjoy the elevated but silky smooth highs or if it's too much for you.
I did have one recording where the CD780s were just too bright -- a latin jazz big band (Ray Barreto) with tons of percussion. Both my Sony CD580s and my Senn HD580s handled it better. The CD580s have a balance much closer to the HD580s, but a bit more forward than the HD580s, but with less pronounced bass and upper treble, but more low to mid treble, than the HD580s. The CD580s have more bass than the CD780s, but it does not go as deep and is not as tight. If you are really into hearing the bass, the Senn HD580s are the best for that purpose.
So, my beloved Sony CD580s (which cost me $40 refurbished!) and Senn HD580s will still have a prominent place in my main rig. The CD580s are siginficantly less bright than the CD780s, by a substantial margin, again striking a balance pretty close to the Senn HD580s. The CD580s are extraordinarily well-balanced phones.
The Sony CD580s are actually a bit more comfortable in some ways than the CD780s, they are lighter and the material doesn't get as warm. It's the same concept with cheaper materials and a different driver than the CD780s. The CD580s look really goofy too, even more goofy than the CD780s. The CD580s don't give you immediate eargasms like the CD780s do, because the padding and the materials are not quite as soft or cushy.
I notice the manual (the CD580s and CD780s share the same manual) describes the CD580s sound as "high fidelity, high resolution sound," and the CD780s sound as "dynamic sound," and I think there's something to that. I think those phrases were well-chosen by Sony. The CD580s I believe are ultimately more accurate. Though make no mistake, they do not have the breathtaking smooth mids or "you are there" realism of the CD780s. I am thrilled that I walked into bargain basement deals on both phones. I consider them both major quality players in the headphone market.
The smoothness of the mids of the CD780s I find really quite astonishing.
I think I'll be using my CD780s for many recordings, but I still have a strong place for the CD580s and HD580s. As D-EJ915 said, if you have a pair of CD780s and a pair of Senn HD580s, you're pretty much set to be able to enjoy any recording or any type of music, IMHO.
For a first hi fi headphone, I would tend to recommend the Senn HD580, since it's more, well, normal. That was my first great headphone. Now, using it as a benchmark, it tells me that my CD580s and CD780s are different flavors, but very legit (and cheaper and easier to drive!).
But if you don't have the money for a Senn HD580 and the additional gear that you may need for it, the CD580s are a very, very nice place to start. I just went back and listened to them and they are no shrinking violets, no joke, they play with the big boys. As I have said many times, I prefer the CD580s to the HD580s for most recordings. That's not meant in a bad way at all. It may well be that I end up preferring my CD580s to my CD780s too.
I think the CD580s may be the best balanced of the three headphones.
Based on these baby CD3000s (which is really what the Sony CD780s are), I think there may be a pair of full-grown CD3000s in my future!!!!!
Seriously, if the CD780s are your cup of tea, the CD3000s will give you more and better.
Looking at the FR graphs I suspect that the MDR-CD580 was designed as a baby Sony CD2000.
Well if you read my meanderings, thanks. It's actually very exciting for me to share the Sony CDX80 experience with everyone, and I'm glad everyone spent just $31, so the debates won't get too heated. In any event, it's just headphones, and I certainly don't mean to step on anybody's toes. I just like to relax and have fun here.
And thanks to head-fi in general, without which I wouldn't have had the information to get any of these fine phones, and at tremendous bargain prices to boot. And thanks to BrooklynRick and BlessingX for pointing out the CD780 deal. Okay, Steve, STOP typing, STOP editing, STOP STOP....