[MattTCG]

Just for giggles, I thought I might make for interesting conversation to contrive a list of preferences that would make up the perfect hp. Choosing your favorite aspects from different makers. There are no rules here so feel free to chime in with whatever.  For me:
 
1. He-400 bass
 
2. Hd-650 mids
 
3. Stax sr-007 treble
 
Wrap it all up in a Sony ma900 frame with a pair of lcd-3 leather pads. Oh course it would all amp perfectly from your phone. 

 
Alternately you could take the bass, mids and treble from the lcd-3 and put it in the hd650 frame and I think I'd be just as happy.  

 

[wolfetan44]

1. LCD-XC bass
2. Paradox mids & upper mids
3. HD650 highs
 
Put it all into.. hm.. a HD700(almost the same as the HD800, but the 800's cups are a little too big).

 

[MadMoxxi]

JVC DX1000 Victor Bass 
AKG K267 Mids and placement
Hifiman HE-6 Highs
Senn HE90 transparency
HD800 dynamics and separation/sound staging width and height
Stax 009 air and body to everything
phiaton ms400 frame and fit style
Ultrasone Edition 8 Metal materials for frame minus the squeaking 
Smaller but still circumaural mrspeaker Alpha Pads with a Shure 1540 style and look
Thinksound On1 Wood Cups
Hifiman HE-500 thin white cable ( or wireless if I can truly have anything )
apple ibud efficiency 
DBIpro 700 metal cable single sided
JVC DX1000 Victor wood Adapter ( but in a 1/8  style 
Planar Driver

 

[jerg]

My (ongoing) modded HE500s are getting pretty close to perfect for my ears. If they have just a tad tighter bass, VERY slightly more energy at 2kHz (I'm talking maybe 1~2 dB more), and better >15kHz extension, I'd call em perfect. I'm not too big on expansive soundstage so that part of HE500 doesn't turn me off at all.
 
So really, any planar bass with good extension, low distortion, and slightly warm tilt toward sub-bass is my thing. A hybrid between LCD2's low~sub-bass, and Abyss's mid~upper bass would be the best.
 
I don't desire another headphone's midrange tbh.
 
As for treble...I used to think that something with relaxed low~mid treble, and emphasized upper treble would be fantastic, but now I have to change my mind about that. Upper treble emphasis = tizziness. Something like my modded HE500's treble (almost linear extension up to 12~13 kHz then roll-off) with a tad more upper-extreme treble presence would be my ideal.
 
As for comfort, nothing beats HD800s. So planars with HD800-like construction? Really all we need is somehow being able to retrofit HD800's earpads onto Hifiman/Audeze cups to kind of achieve this in a practical sense.

 

[MattTCG]

Jerg...that's wonderful that you found a near perfect hp in the he500. I think that it all comes down to personal preference and what we're willing to live with. Possibly an he500 that was just a bit lighter weight would really be near perfect for you.
 
It would be foolish to think that hifiman was working seriously on a new product. It's just a question of when it will release and what it will bring to the table. I definitely look for them to offer a new full sized hp in 2014. Audeze is stepping up to the plate with some very compelling offerings and I look for hifiman to follow suit. 
 
If hifiman could offer:
 
*he400 bass
 
*he500 mids and treble
 
*he-4 weight
 
...then I'd be all over it. 

 

[Claritas]

My closed over ear recipe:
 
Sennheiser HD600 gentleness
Denon AH-D2000 comfort
AKG open sound
[spot reserved] clarity
Koss KSC75 weight
Grado SR225i speed
MB Quart QP805HS indestructible
Beyerdynamic DT880 2003 looks

 

[MattTCG]

^^ I like it. Closest thing to ksc75 weight...ma900?