These beauties arrived on May 31 and I have barely been able to take them off since. <3
I will say upfront that I am by no means a pro-level audiophile; more like I'm a music lover first, audiophile second. But I do appreciate fine details, especially in sound & music, and my god -- these headphones just make everything SPARKLE.
I listen to a fairly wide spectrum of music -- rock, jazz, jam bands, blues, funk, electronic, metal, punk, hard rock, some hip-hop, etc. -- and everything I try just sounds amazing through these.
(For reference, my first real dip into audiophile-quality headphones was the AT-M50x; these are still in use today at my desk at work. Then came the K7XX, after I'd been bitten by the Massdrop bug; I mainly use them for vinyl listening these days. Then I discovered the unique little Romanian company Meze and their beautiful 99 Classics -- these have become my favorites for closed-back use and are WONDERFUL for electronic music, in particular; I also have the 12 Classics earphones for my commute).
So, personally, the HE4XX was the next logical step for me. I had tried a pro/reference-level set (M50x), a superb open-back dynamic set (K7XX), and a really fun and unique closed-back set (99 Classics). I was very curious about planar magnetics, but obviously most of the planar cans out there are quite expensive. But then these come along from a big name like HIFIMAN, from a community which (generally) knows their stuff, and for a sub-$200 price tag? How could I say no?!
Well, I'm happy to report that I am just delighted with these gorgeous pieces of audio engineering. If you haven't heard the difference between dynamic and planar yet, these are the perfect entry point. Amazing clarity in the highs, water-tight mids, and deep, DEEP, accurate, fast, satisfying bass. ALL THE BASS. (Now I know what people mean by "that planar bass SLAM"! Outstanding). And I think I should note, too -- I wouldn't say these are really "basshead" headphones; in fact, the 99 Classics are much more bassy (but also closed-back, so that's part of it). This doesn't mean you won't get some nice, big, fat waves of bass if you are listening to tracks that have it -- you most certainly will, so make sure you're wearing clean undies -- but even in tracks that don't have a huge amount of bass, you'll still hear all the bass there is to hear in whatever you're listening to. These headphones just cover every possible spectrum in human hearing, so you're going to hear it ALL.
(Provided you're listening to lossless goodness with a setup that doesn't get in the way, of course).
For that reference, I'm typically listening to FLAC when I can, or at least high-quality mp3 (usually V0 or 320) thru the JRiver Media Center (PM me if you're curious -- incredibly powerful software), out to a Schiit Modi 2 DAC, to a Schiit Magni 3 amp, delivering it all to my ear holes via bit-perfect WASAPI connection.
Oh, and they're also very, VERY comfortable.
My only complaint, honestly? Cable's a bit too short. Would like to have a longer option, though I'm sure that's easy enough to acquire. I just haven't looked yet.
Overall, I absolutely love these headphones. They have once again rejuvenated my love of my favorite hobby, which is simply listening to music. See for yourself.