[Annirak]

Full disclosure: I tried posting this question once already, though a bit differently and got no replies.
 
I have been frustrated for some time with my SRH750DJ.  There are a few things I don't like:  They squeak when I put them on, take them off, or adjust them.  They are not particularly comfortable.  They squeeze my head too much and they bend my ears.  They have a decent sound signature, but they seem to take a fair bit to drive at low frequency: neither my computer, phone, nor tablet seem to be able to drive them adequately. I don't like the plastic construction.  I have now both had a hinge break and had part of the headband crack.  The first under warranty, the second not, though it is apparently repairable.
 
Given my frustration with driving my headphones, I jumped on the Geek Pulse Indiegogo campaign (Pulse X with all the uprgades, but no LPS).  That fixes one problem, but there are still several more that can really only be addressed with a new pair of cans.
 
Here's what I want from my headphones:

1. Closed back; I use them at work and I want the sound isolation.
2. Comfy: I use them for long periods of time
3. Solid construction, preferably metal structural parts.  I don't want to deal with breakage in the structural components just from every-day use.
4. Removable cord--Ideally, I want this to be a 4-pin or a 2x2-pin cord, since that means I can re-cable them for balanced operation.
5. Neutral audio reproduction

 
I listen to primarily and in order:

1. Electronica
2. Rock
3. Pop

Some other genres sneak in occasionally.
 
I'd really like to be able to audition my next set of headphones, mostly for the comfort aspect; I live in the UK.  I hear that most of the large department stores (Slefridges, Harrods, John Lewis) will let you audition some of the high-end cans.
 
So far, I'm a bit drawn to Mr Speakers Alpha Dogs.  They're outside the range I've quoted, but they seem like the best bang for buck.  I'm also interested in the Sennheiser HD650, though while they are less than the Alpha Dogs, they don't have the option to ship with a balanced cable and they are open-back, which makes me lean a little more towards the Alpha Dogs.

 

[billybob_jcv]

I think there are some very good headphones in the $300-$500 range. Many of them will need an amp - including the Alpha Dogs.

Other closed-back choices include:
A-T ATH-W1000X
A-T ATH-A900X
Shure SRH1540
Shure SRH940
PSB M4U-2
NAD Viso HP50

 

[TwelveTrains]

+1 Shure SRH1540

 

[Annirak]

I think there are some very good headphones in the $300-$500 range. Many of them will need an amp - including the Alpha Dogs.

Other closed-back choices include:
A-T ATH-W1000X
A-T ATH-A900X
Shure SRH1540
Shure SRH940
PSB M4U-2
NAD Viso HP50

@billybob_jcv, there's a lot of good suggestions there.  I'm going to have to go through each of them.  Except the SRH940.  I'm not interested in anything with the same construction as the SRH750DJ.
 
Any thoughts on MrSpeakers Mad Dogs?

 

[billybob_jcv]

lol - I can't believe I left off the Mad Dogs! I think most people would call me a Mad Dogs fanboi. I think they are excellent headphones and an absolute bargain at $300. I'm not sure how they stack-up to the higher priced cans on that list. They do need an amp, and they are fairly heavy.

 

[Annirak]

I'm more and more drawn to the MrSpeakers Mad Dog.  I've heard that there are some competing Fostex T50RP mods, but MrSpeakers seems to be the most available and there's the Alpha Dog upgrade option.  I really need to find someone in Cambridge/London who will let me try their Mad Dogs once my Geek Out arrives.

 

[xFairyxTailx]

I loved my Mad Dogs but the allure of the Alpha Dogs was too much, I highly recommend either of these.

 

[billybob_jcv]

The Mr. Speakers Mad Dogs just seem to hit the sweet spot of price vs sound vs availability for the T50RP mods. If you think about it, just about anyone could start a business based on modding the T50RP - and many people have. There are other guys out there, but none of them are as quick, easy, quality consistent and inexpensive as Mr. Speakers. He added value where it was needed the most - a good implementation of the cup mods, excellent pads, a better headband and a good quality cable. You can argue that that there are better sounding, or prettier or cheaper T50RP mods - but I think you would have a hard time saying anyone else is all three. I get no kickbacks from Mr Speakers - I have met Dan once, briefly, and he doesn't know me from Liberace - I just happen to think he has done a great job and I'm proud he's in the head-fi community.

Now - with all that said - if you have some patience and a decent ear, you can do the mods yourself. The BlueMonkeyGlider (BMG) instructions and modding guides are clear, concise and easy to follow. BMF, Smeggy, LFF and the rest of the T50RP Modders have my utmost respect and thanks - IMHO, they are really what head-fi is all about!

 

[Annirak]

The more I hear/read the more the Mad Dog sounds like the right set of headphones for me, with the possibility of upgrading to the Alpha Dog later on.  The problem I have now is that the last set I bought was not particularly comfortable and had some build quality issues.  While everything I read says that the Mad Dog are really comfortable, solid, and have a great sound, I'm still a little leery of buying a set of headphones I've never even seen in person...

 

[Annirak]

I found a second hand pair of mad dogs I was able to audition. The sound, to my ears anyway, was a bit better than the SRH750DJ. It didn't blow me away, but it was better. The comfort and construction were miles better. I bought them.