OK, spent some more time on the graphs:

Green is what I have now - I knew there was a fairly high 'bass boost', but wasn't really aware if the inaccuracies at the top end (they all seem to suffer from this, but not as much as mine!)
Beyerdynamic DT990 (orange) was another one I was considering that seemed to get good reviews in the price range - but they would appear to be very little improvement over my current ones? (So maybe my Senn's aren't as 'bad' as I thought!)
Red is the AKG702 (one of my original choices), and Blue the Sennheiser HD558 (recommended above) - remarkably similar in bass/mid ranges, with only minor differences in the top end...
 
So without moving up to more expensive ranges (AKG K712 / Q701, Senn HD650 / HD800 etc) these seem to be my preferred options. I may have to look to see if I can find anywhere nearby that I could try them, but I'm not sure that's feasible....
Otherwise, I'll just make a choice and order one and see how I get on.
 
Thanks all,
Paul

paulf707
 

interesting chart, never bothered to look before but explains why I did not like the DT as it sounded too HiFi (which the bass boost on the chart explains quite clearly)

Don't worry too much about the wild swings in the high end. They are typical for all headphones and not necessarily showstoppers. Look for two things: hyped bass and flatness through around 3-4 KHz. The hyped bass you can compensate for with EQ as long as it's fairly smooth from 60 Hz on up. A flat response in the midrange is going to have a greater impact on mix portability. You can see why the AKG 702 is a studio standard.
 
However, I don't know how important it is to obsess over minor weaknesses in cans. Have a look at the graph for the very popular ATH-M50s - ugly! Yet they are widely used and, IMO, a good value for editing. Personally, I am a fan of open-back headphones. I've been using those Sennheisers for a few years now and they remain my favorite, although 702s would be a suitable replacement if I ever lost or broke them.

Thanks bitflipper... which Senn's do you use?

Newbie question here (I apologize if I'm hijacking this thread but it seems to fit to me):
 
I've been looking at the AT R70x which appears to be similar to the Senn HD600 but with extended bass response. It's considered very polite, pleasant to listen to, very comfortable, but doesn't expose details very well, which lets you use it for extended periods with little ear fatigue. Some call this a "veil" over the sound. The Senn HD600 appears to share these traits as well. The sound is considered well balanced.
 
Then there's something like the AKG702 or DT880 which exposes everything. You hear the details, which could be great for editing but causes ear fatigue after ~1hr or so. And it's considered not as comfy. And many consider its treble hyped.
 
I have the AT-50x (closed back) for tracking but I'm looking for an open back for editing. Which is considered more important: exposing hyped detail or being able to sit a spell in comfort w/o ear fatigue?
 
Anything else to consider? I don't have the ability to audition these so I'd like to estimate as best I can to get something I'd like. Style of music: acoustic, folk, Americana, classic rock, pop. No jazz. No metal. No hip-hop. Not yet anyway.
 
Thanks.

Welcome to the discussion! - and thanks for bringing more options into view....
I couldn't find the AT models you are looking at on the graphs site, but here are the frequency responses for the others:

From what I've read K702's are considered 'flat' and show the most detail (as you mentioned) - but are possibly a little 'light' on bass response (although slightly better than K701s)
Based on that description the HD600 seem to have similar frequency response. The bass is slightly lower below 40k (but I doubt that is noticeable), but slightly higher above 70k - which I assume would translate into 'more bass'. They do appear to have slightly difference peaks in mid/treble (2k-3k vs 3k-4k) - not really sure how much difference that would make to listening?
The DT880 would appear to have more bass (and DT990 significantly more). They both seem to have a peak around 8k-9k so I assume they would sound considerably different to the other two.
 
Not sure if that helps....??
 

Thanks paulf. If you read some of the Hi-Fidelity headphone forums you'll see a general consensus that those freq response graphs are largely meaningless. The various headphones sound different in ways the graph does not address - soundstage (left, right), 3D (front, back), how much punch (some compressive effect?), etc. Then there's the whole "burn-in" aspect. Some phones need it (like the K702) while others don't (R70x). Not sure I buy into any of that, but I also can't argue against people swearing they hear a difference. I'm a big, big believer in frequency response being THE major determination of how a headphone sounds, but I'll be using Sonarworks compensation so the frequency differences should largely be calibrated out. That leaves the other issues such as fatigue, loss of detail, unrealistic soundstage, etc to look out for.
 
On the one hand, I hate uncomfortable headphones. I wouldn't want to sit with them over an extended time period. On the other hand, I'm not supposed to sit and mix over an extended time period or my ears will lose the ability to listen analytically. It's not really a comfort issue but the loss of ability to distinguish what sounds good (I tweak and tweak and tweak but when I compare to what I started with my tweaks sound horrible). So maybe I don't care about comfort? But I want to mix in an environment that is a joy to work in. Comfortable headphones is part of that. So, it seems I'm back to choosing between comfort with a pleasurable listening experience (AT & Senn) vs one giving me more analytical/detailed editing but somewhat uncomfortable experience (K702 & DT880).

Seeking any opinions and insight from users of both. Who knows, maybe I'd be happy with both.

I have looked at a number of articles / reviews on head-fi and similar, and I wonder if their needs / requirements etc are different to those we look for (from a mixing perspective). From a logical point of view, I'm also sceptical about the 'burn in' issue, but (as you said) there are far too many people discussing it for it to be completely irrelevant.
I'm coming to the conclusion that while my Senn HD25-SP headphones have their issues, they are not 'that bad' compared to some others. I think I will look at getting some 'open' headphones as I'm keen to see the difference. I'm thinking that if I make sure that the ones I get are significantly different (from a frequency response perspective) to my existing HD25's, then at least (if nothing else) I will have 'different options' for listening / mixing etc. I can use the two different headphones to compare mixes, and also vary the sound (which may help with 'mix fatigue' and similar).

Avantone has a new set of headphones on the market that's been getting a little buzz.  You might want to look into those.  They're made especially for mixing and have several settings on the headphone.
 
http://www.americanmusica.com/Item--i-AVN-MP1-LIST

Yep, saw those in the last SoundonSound.... not really sure..... They're a bit above my budget (but if I was that impressed by the idea I'd probably find a way to increase the budget!) - I think I'm discounting them because a) they're closed (I think I want open backed), b) I don't think a 'mono' switch is a particularly great benefit and c) I'm not sure that emulating 'mixcubes' are of particular use/interest to me....
But I have to say I love the design / colour :)