Impressions are almost always glowing on every headphone reviewed wherever you go. Headphone reviews almost never border on the negative side. Negative reviews tend to be from people who whine about the headphone breaking on them, and not about actual quality.
I haven't had an extensive time with the A900x, but all I know is that for the price... I'd easily go for cheaper headphones which definitely sound better to me.
We do all hear things differently, but I like to believe my impressions tend to fit the general impression of headphones, when it comes to sound signature and overall quality.
The A900x came off as rather boring and overpriced. It lacked energy, impact, and weight. It sounded rather flat and just.... there. There was nothing engaging about it's sound. Not the bass, not the mids, not the soundstage, nothing. If I wanted something bland, I'd have paid less than $100 for something else that isn't going to inspire me in any way.
I found the Audio technica's own ESW9 to be much more engaging and lively, with better impact, better interpretation of vocals, and a great tonality. Yes, it's on ear, but it trumps the A900x in everything but sheer size.
As for the K550, I won't even go there. It seems so ridiculously sensitive to seal and placement, I call it a fail in design. I literally had to press the cups to my ears to hear anything remotely worthwhile. If I let it sit there... it was... just not good.
I tell you what, I'll go to a few different stores and demo both again, and take my E17 again. I'll give them a longer demo. I don't expect my impressions to change, but I will at least attempt to hone in on the specific qualities of it (or lack therof). it's been awhile since I heard them. All I know, is that they did nothing for me every single time.
OK, MLE. That would actually be awesome.
But I find that impression... I dunno, strange.
Every review is subjective of course but if you search for them here on head-fi, there are like 4 reviews and I went pretty much through countless google searches and read many review on them and the words "boring" or "bland" or "not lively"... They just don't fit there. They ain't there.
Treble - extended, detailed, beautiful
Midrange - full, luscious
Lows - punchy, tight, sometimes a bit too pronounced, roll-off bellow 50hz, so not very extended I guess, EQ helps there if problematic
Soundstage - awesome for a closed can, more wide than deep but very well defined
Instrument separation - great, easily pin-pointable
Great for music, gaming & movies...
That's pretty much what pretty much every review said.
Energetic, fun but still close to balanced, slightly south of neutral.
It's just the polar opposite of what you said, that's what bothers me.
SAID THAT, there have been quite a few defective pairs. Maybe the one you demoed were? I know two batches were defective, or at least a good bunch of these [namely 03 and 05-2012 I think].
These might exhibit such flaws. Don't really know...
I am not questioning your ears. Perhaps, you have different preferences? My reference headphone is the HE-6.
But a guy here has a similar setup to me and found the A-900X very good for their price [in comparison to the HE-6 for instance] so... I just dunno.
I guess. Yeah, if you could demo them once again, that'd be great :]
