I will also be interested to hear the HD820. May be finally there will be an isolating closed headphone as good as the TOL open back headphones ??
I auditioned the 820 and a few headphones at a shop. Here is my preliminary thoughts on headphones ranked best to worst:
1. Beyerdynamic t5p: Reaches analytical levels of detail and resolution while remaining fun. The only headphones that allowed me to get lost in my music. Fun sounding, treble is sparkly but rolls off right before becoming harsh (perfect). Mids are absolutely lush. Full and thick and velvety with vocals. Bass is tight, controlled & punchy with excellent texture. Over-all detail is controlled, sounded the most musical of the lot. The angled drivers do give a sense of soundstage that seems to give air to lows, mids and highs. My ears are tiny so super comfortable as well. Isolation was the best with this headphone too: the shop owners were talking 3 meters away from me and I couldn't hear them at all. My music was enveloping me. And I was hearing things I never heard before. Also the only pair of headphones that made bad recordings sound musical and lively. I think I love this headphone?
2. Denon D7200: My second favourite sounding headphone, take everything about the t5p and add a little more rumble to the bass (gives the feeling it extends deeper) and wider sound stage. This comes at the expense of sound leakage with a more semi-open design. Isolates similarly to the TH900.
3. Sennheiser HD820: Large, thick sound. Detail retrieval is good but boring. Closed back brings in soundstage. More intimate, but also definitely more congested than the HD800 and HD800s. It lacks the air around the lows, mids and highs the t5p had, but sounded more fuller as a result. I found this headphone to be pretty meh, considering it's more expensive than the HD800s, which sounds better, even at the expense of open back design, because these don't even block out sound that well. These isolate similarly to the TH900 and D7200, i.e. the closed back is actually more 'semi-open,' sound will still leak in/out of the headphone.
4. Fostex TH900: I'm surprised this made it so far down my own list. I agree with another reviewer's opinion here - I don't understand why people love these headphones. I'm looking for cans for predominantly Techno/house music and these headphones seemed to be it. However the bass was too rumbly and deep for my liking (seemed inaccurate, but there was heaps of it). I definitely "felt" it but it was over-whelming. Too much. And the mids were very meh. Treble was OK. I found the headphone boring and uninspiring. Suffers the same semi-open problem as the D7200 and HD820.
5. Focal Elegia: I disagree with certain reviewers who claim this is a better purchase cost-price ratio and beats the t5p. I'm paying the extra 500 to get the t5p, because it's better in every way. The Focal Elegia in a word is boring. The detail is there, but it's not engaging. Though at the $600 mark, I'm not sure what other closed back options there are. Either way, I wouldn't buy it.
If anyone has any questions, I'll try my best to answer them based on my personal subjective experience. I've read reports the Ether Flow C is marginally better than the t5p in every way, so I will be auditioning that next.
