Pros: imaging, clean sound
Cons: no carrying case included
I have been using AKG K550 for past few weeks and enjoying them pretty well. This is my first foray into mid fi and I think its a solid contender for getting into mid fi sound especially as it has very low barrier for entry (whole setup). I am driving it with Audinst hud mini, entry level dac/amp and it drives it with authority and good clarity.
I have been using Sennheiser HD518 extensively, and have auditioned HD595 as well as HD650 before this. So thats my reference point here as HD5XX series is rather popular and what you can expect to get if you go for K550.
First some sound signature differences between sennheiser and akg. k550 requires you to be engaged to music instead of being half asleep to enjoy. k550 has this comparatively thin sound that changes very fast according to notes being played, thus conveys note level information with much more clarity. this clarity improves dramatically in hd650 but still k550 is clearer. For me, I need to actively listen to music and be engaged to enjoy k550.
So is one inherently better than other? I don't think so. both sounds are usable according to mood. (its not that I am feeling sleepy all the time, so why Sennheiser only collection?)
So now about K550. First some observations about K550 that are striking:
Great isolation without any clamping pressure whatsoever. No seal issue for me. I would attribute this to ear pad material. Its most certainly is something special that blocks sound very well. It must be in contact with your skin to achieve seal.
Very forgiving for low bit rate material. my much lower hd518 is almost un listenable out of phone with lower bit rate tracks as I could see some holes in music. k550 polishes it and makes it listenable, I think. It might have something to do k550 being easy to drive, not sure why it does that.
Very clean sound. no grain whatsoever. hud mini is inherently grainy and with grainy old recordings of the old like led zeppelin, it was almost un listenable on hd518. (all three recording, dac/amp, headphone are grainy making too much of it). on k550 its pristine.
Now I would describe frequency response a bit:
Bass: awesome. Goes very deep, is tight and reasonably textured. Exactly what I wanted.
Mids: Rich, detailed, not upfront. very enjoyable.
Treble: Now I am terrified of sibilance or bright sound. But k550 sounds exactly like I wanted it to. I don't think its dark sounding, but its got this peculiar way of doing treble. Treble extension is good but detail is very less thus to my ears sounds perfect. (better safe than sorry. won't cut any points here cause of my preference. I am looking for enjoyable headphones than perfect ones).
A word on soundstage:
Good sized. Its a closed headphone and has good width and depth with that limitation. Most impressive part has to be imaging. Pin point imaging if its present in recording, even if two same instruments are playing, it places them very well in sound stage.
Comfort is very good as it exerts very little pressure on head, but as its a sealed design, it gets sweaty. Ear pads don't allow a lot of breathing.
Build quality is good mixture of metal and plastic. not built like tanks and I intend to take good care of them. especially i don't want to change alignment of cups and thus affecting seal.
All these things make them a worth can but what makes them 5/5 special is, well they are very enjoyable. Even with their relatively thin sound, they have this deep and satisfying bass thus make for a very convincing presentation. Their sound stage is wide but they don't have diffused presentation like my HD518 that renders each component of music completely separate. Instead it presents a good mix of music, instruments often inter lapping but still sounding separate with note level detail, harmonious with each other. If you think about it, that is how you hear music when in a hall with musicians. Not completely separate from each other.