
I've got the Black Dragon on my HD650's and really enjoy it. It opened them up a bit across the range but they've ben on for so long that I really don't remember what the stock cable was like. I did have the HD25's with the Silver Dragon IEM v1 and it was really nice. Tried the silver on the HD650's and it was awful. Lost all bass impact and sounded very hollow.
For the HE-400, I wanted to go a different route and went with the Q cable. This cable is so light you don't even know it's there. I really disliked the feel of the stock HE-400 cable. Again, it opened the HE-400 up across the range and made the sound fuller. Just my opinion. Is it worth the $$, probably not. If I were to do it again, I'd probably go Toxic for half the price. All in all, I'm pleased with the cables but its a lot of bucks for a bit of improvement.
I'm liking what I've bee reading about the Lyr in driving both the HD650 & HE400. That will probably be my next purchase.
BTW.. between this thread (thanks for the great review Matt!) and hearing the LCD-2, I decided to sell off my HD25 & Silver Dragon to get the HE400. No looking back, I love the HE400.
Edit: just ordered the velour pads.. looking forwards to trying them.
Thanks for the info on your experience with cables....you may have set my HD650 decision to Black instead of Silver (once I get my replacement drivers...) That sounds more the direction I'm looking for (I'm uncertain that I'd ever like silver on any headphone....) Nor do I want my HD650s to stop being HD650s by turning them into Beyers 
I'd probably stick with Dragon for the HE400s. I am astounded at the Q Cables pricing, and dislike a little of their snaky rhetoric. Not that ALL cable vendors aren't selling some level of snake oil, but at least with Moon, there's pretty much a "here it is, take it or leave it" approach rather than endless self promotion and shaky pseuo-science justifications! But honestly, despite disliking the feel, to me the HE-400 sounds great just as they are, I'd be almost afraid of ruining the magic with either velour or a new cable!
HE-400 is indeed pretty special. LCD-2 is the only other headphone at this point that really interests me. I get tempted by the "perfection" that is HD800, but I think the treble would drive me off the deep end. The weight of LCD-2 concerns me, and the $1k pricetag ($1500 for HD800? Sheesh), is frightening compared to a collection of different cans with different sounds. I'm not sure I could get myself to pay full price for them considering every time I listen to HE-400 on Lyr I always think to myself "what could LCD-2 do for music that this can't do?" Despite the lectures of "headphone x is superior" that mentality always holds for me until I put them back on my head, and then I'm still left wondering what exactly "better" means. There are no issues I wish to correct, other than maybe weight or soundstage. And LCD2 won't help the first and will marginally help the second. It's all too easy to get sucked into "this headphone is technologically superior so I want it." I won't dispute Audeze's build superiority though. And the HiFiMan soundstage could be EASILY fixed with some deep angled cups if they ever make them.
Be sure to report back on your experience with velour. And also how easy/difficult it is to install them. I still can't get a feel for how to go about a pad change. I'm still not sure I'd change...the pleather is so darn comfy!
By the way, your comment earlier about having heard the LCD2 and finding that they're far better and worth that price, once you're up to the $1k level (plus HE-400 and HE-500), it's all subjective. There are people that prefer HE-500 to LCD-2, most consider them equals. There are some, thus that prefer HE-400 to HE-500 for the sound signature, such as Matt (though it sounds like that opinion may be changing?) So if a $700 can is equal to the 1k can, some prefer it more, and some prefer the $400 can to the $700 can, is the LCD-2 really worth $600 more? Probably not. If they were all the same price, the opinions would probably be evenly split, or maybe only a slightly smaller portion picking 400. I still stand by the opinion that HE-400 is a hard to categorize because it costs less than HD650, but has more in common with HE-500 & LCD-2 than it does with HD650 in terms of performance. It's what the HD700 should have been, for less money. The only thing that keeps HD650 in the game at those prices is that its sound signature is entirely unique and you can't get get it anywhere else.



























For $100 a foot, that stuff better make breakfast.






