[PurpleAngel]

I am interested in what the Hifiman velour pads would do for them, though, as was mentioned a while back.

The Hifiman Velour ear pads do help hold the A900X in place.
I'm not sure I had a noticeable improvement in audio quality.
But right now I'm using the A900X/Velours to listen to PF Welcome to the Machine and it does sound nice.

 

[elvergun]

I've seen quite a few favorable comparisons between the Soundmagic HP100 and the K550. Might be worth a look into.
I agree. In the <$300 range, you won't find anything that clearly outclasses the K550, although it's certainly possible you might find a headphone you like better because of the different sound.

This!!!
 
I think that if you want a closed, full-sized can that is superior (not a sidegrade) to the K550 you are looking at the Alpha Dog and at a price of $600.

 

[Claritas]

I think OP has made it clear that by "upgrade" he meant lateral move to something better-fitting.
 
DT770, SRH840, and SRH940 all fit fine.
 
DT770 is the most comfortable and built very well too.
 
I prefer the sound on SRH840 because it's not so extreme, but the headband might need some modding for comfort.
 
SRH940 is my least favorite of the three because the highs can be too hot and the build is a little delicate.

 

[chocolatewol]

  The Hifiman Velour ear pads do help hold the A900X in place.
I'm not sure I had a noticeable improvement in audio quality.
But right now I'm using the A900X/Velours to listen to PF Welcome to the Machine and it does sound nice.

For whatever reason I haven't had too many issues holding the A900x in place on my head, though I know lots of people have had slippage issues. If I ahd had the issues some people have, I would have been much less keen on these, for sure. I would be interested to get some velours or the W1000x pads someday, though. 
 
As for the HP100s... I'm not sure I want (what was described in a few reviews I quickly sifted through) a much brighter sounding headphone to go with these (and the others I have). I'd have to hear it to be convinced, I think. Edit: I don't mean that I necessarily believe or understand how they compare, but brief impressions (which I am ever trying to evolve) + redundancy would have me shy away unless demonstrated.  

 

[chocolatewol]

 
This!!!
 
I think that if you want a closed, full-sized can that is superior (not a sidegrade) to the K550 you are looking at the Alpha Dog and at a price of $600.

Well explained take! 

 

[Lorspeaker]

  For whatever reason I haven't had too many issues holding the A900x in place on my head, though I know lots of people have had slippage issues. If I ahd had the issues some people have, I would have been much less keen on these, for sure. I would be interested to get some velours or the W1000x pads someday, though. 
 
As for the HP100s... I'm not sure I want (what was described in a few reviews I quickly sifted through) a much brighter sounding headphone to go with these (and the others I have). I'd have to hear it to be convinced, I think. Edit: I don't mean that I necessarily believe or understand how they compare, but brief impressions (which I am ever trying to evolve) + redundancy would have me shy away unless demonstrated.  

 
take some doublesided window windprooftape...n tape to the size u need on the wings of the AD.
or any strings u can find ;P
 
ADs are on the comfortable side of headfones around. 
 
I find the k550 v comfy on my head actually..but it died on me .. haiz.

 

[elvergun]

  I think OP has made it clear that by "upgrade" he meant lateral move to something better-fitting.
 
DT770, SRH840, and SRH940 all fit fine.
 
DT770 is the most comfortable and built very well too.
 
I prefer the sound on SRH840 because it's not so extreme, but the headband might need some modding for comfort.
 
SRH940 is my least favorite of the three because the highs can be too hot and the build is a little delicate.

 
But the signatures of some of the headphones you recommend are completely different from that of the K550.  When someone wants to upgrade I assume that they want to retain some of the characteristics of the model they already own.  If a Sony MDR-XB500 owner wants to upgrade, I would never suggest the K701 unless they mention that they want something with less bass.  The DT770 is a great headphone, but it has to much bass for my tastes, and perhaps it will have too much for other K550 owners. 
 
There is not much out there with the same characteristics of the K550 (full-size, closed, balanced) for less than $300. 
 
Yesterday I forgot to mention the Mad Dogs (full-size, closed, balanced)...they are a worthy sidegrade to the K550s.

 

[Claritas]

But the signatures of some of the headphones you recommend are completely different from that of the K550.  When someone wants to upgrade I assume that they want to retain some of the characteristics of the model they already own.  If a Sony MDR-XB500 owner wants to upgrade, I would never suggest the K701 unless they mention that they want something with less bass.  The DT770 is a great headphone, but it has to much bass for my tastes, and perhaps it will have too much for other K550 owners. 

There is not much out there with the same characteristics of the K550 (full-size, closed, balanced) for less than $300. 

Yesterday I forgot to mention the Mad Dogs (full-size, closed, balanced)...they are a worthy sidegrade to the K550s.

That's a fair point. I figured it was unavoidable. So maybe the Shure 840.

MD isn't completely sealed; otherwise, I would certainly have mentioned ZMF.

 

[elvergun]

That's a fair point. I figured it was unavoidable. So maybe the Shure 840.

MD isn't completely sealed; otherwise, I would certainly have mentioned ZMF.

I owned a pair of MDs…they isolate pretty well…they pass the noisy girlfriend test. The 840s are also a good choice.

 

[Lilac1]

Bumping this due to a similar situation. Clear upgrade from the K550's, open or closed below $600, any ideas?

 

[chocolatewol]

Anyone have an idea on the comparison of the SRH1540 and K550? Apart from the SRH1540 having supposedly augmented bass, I wonder how they compare in terms of soundstage, instrument separation and mids/highs. I'd also like to not have to pay $500, but that's another story..

 

[tumtuter]

Hello Headfi'ers,
 
Please could someone with the knowledge/ experience tell me if upgrading from the K545 to the K550, would improve a lot on the soundstage & spatial detail.
 
The reason I ask is because the K545's soundstage sounds quite small to my ears. Primarily would be using the phones for gaming so need to have the best soundstage possible for positional cues.
 
Or is there a better closed can alternative. I've read that the K550 has the biggest soundstage for a closed back. Is this still true?. Also how much of a difference would the K550 be say compared to the K701. Would a open back headphone be necessary.
 
PS. please leave any recommendations below also. Budget ideally £100 or £250 max for any exceptional headphones which exceed in terms of soundstage & spatial detail.
 
Thank you.