Just got X2 after many years of owning HD590.
They are definitely much heavier, not as comfortable. Bass and treble seems over exaggerated. Smoothness and details is not there as in HD590.
I will probably return them and give HD600 a try. I've read a lot about how comfortable they are, but that's not what I am experiencing so far.
I got X2 for 20days, listened to them extensively before returning.
After a bit of use the clamping force is less pronounced and they are quite confortable. But not AS confortable as HD600/HD650, that's for sure!
Look down for other answers/opinions of mine about these cans.
You haven't stated how long you've had your X2s? As many here have noted these cans need a considerable bit of burn-in. Give 'em some time and I think you may change your mind. I'm a long time HD540 owner and at first I didn't care for the X2 either. The pads were itchy, clamping force too strong, the extra long fabric cord is funky & microphonic and the SQ wasn't that impressive right out of the box but I've since come to love these HPs after sufficient burn-in. The bass will settle in and becomes very appealing. I like to add some EQ using Foobar and the sonic result is sublime.
I did experience a bit of driver burn-in within the first ~10-20hours or so, after that I got only brain-in; I say that because I burned them for around 250hours before returning and before 200hours I just listened them for something like 10mins per times, then some burn-in, then hearing them again, etc and to me they sounded all the time THE SAME as when they had ~20hours of use.
After around 200hours of burn-in I listened extensively to them with many different music genres, different quality of mastering and different source materials.
After a while my brain was settled (brain-in) and I honestly enjoyed them more compared to the beginning, but that was only cause of brain burn-in, not driver burn-in like many are saying!
The main sonic quality of these cans is in the bass region. The sub-bass is present. The bass is present. The medium bass (male voices) is present.
The sub-bass is a bit too much in quantity for a neutral can, so this isn't a neutral can, whatever people says.
The bass and the medium bass is really top notch, male vocals are really well presented and engaging, on pair with HD600/HD650.
The main minus of these cans is in the medium-high frequencies (female voices). Female voices are quite thin and recessed and sometimes just weird sounding, not for sure natural/neutral and well presented. Compared to HD600/HD650 here is the biggest difference: Sennheiser just defeat these X2, there isn't really too much to argue about this if you compare both matching volume.
The highs region isn't that bad to me, maybe not the top quality of this cans but not bad at all, I could easily live with it if I had too, without many complaints!
The soundstage presentation (depth and width) is quite different from HD600/HD650 but I think this is only a factor of personal preference here. HD600/HD650 has a sort of intimate and more forward presentation where vocals are taller compared to X2. This one has a more distant presentation like if you were sitting in back raws at a concert but the soundstage seem to me more large in comparison.
That said, I don't mind to put X2 in the same league of HD600/HD650 because those for me are above, without a doubt.
I 'm saying this in a HIFI point of view, where high-fidelity means neutral and natural and those X2 are not, mainly in the sub-bass and the female vocals areas.
I could easily suggest these cans to someone which likes more "fun" headphones, to those looking for a good videogame/movie pair of cans and to those with medium budget which don't mind to buy an headphone amplifier later.
A good pair of headphone for sure, but not a must-have as many says, to me!
