"The sweet is never as sweet without the sour."
Very important quote. And I just realized how true it is. I've been listening to my HD650's everyday for so long that it's become the norm to me.
Now compared to "non audiophile people", ATH-M50's are pretty good headphones. They were my temporary headphones while I searched for a replacement for my HD595. Now they're my wife's headphones she uses for gaming and music on the computer.
I just did some side by side testing between those and my HD650's earlier for fun. MAN. The difference is very large. It's surprisingly larger than I thought it would be. I know with headphones, and most things in life, you get diminishing returns after a certain point. But apparently the HD650's are heavier hitters than I originally thought. The M50's sounded tiny. Claustrophobic.
Also, the top end of the scale sounded too harsh. That could merely be me being used to the slightly rolled off highs of the HD650's, but it just sounded like the highs were reflecting around inside the closed cups of the M50 and were straining my ears. (example: finger snapping on Lorde - Royals) On the HD650's, the high pitched finger snapping sounded subtle, which to me, sounds like a background layer to the song, like it was probably meant to be. On the M50's, it was so overwhelmingly loud that it was distracting me from the mids. Where WERE the mids? The strong bass and harsh highs were possibly distracting me from the mids. Upper mids and lower highs were good. Bass is good, being a closed can. Can't really knock the can comparing it to itself, or other cans in its price range, but when you compare them to the HD650's... there's no competition. (and wearing other cans makes me really appreciate the lightness and comfort of sennheiser headphones)
I went back to my HD650's and it was such a relief. The open cups give me that open airy sound I like. The soundstage was MILES larger. Airy and spacious. Not bad spacious, as if you're in a large echo-y room, but spacious as in I don't feel crowded. Everything across the board sounds balanced to the point where one voice (not necessarily human voice, can be instrument voice, etc) doesn't distract or wash out other voices. I can hear every layer and instrument and voice in very clear crisp detail. The word crisp might make it sound like these cans are analytical, but they aren't. They're warm. Best mids I've heard. Perhaps the HE-400's that are in the mail will convince me otherwise? By crisp, I meant each instrument/voice isn't melting into one another like on cheap cans, where can hear the different instruments/voices, but can't hear where one ends and the other begins? It's terrible wording, I know, but I'm hoping you get the gist of what I'm trying to explain. The bass isn't really that bad either for being open cup. I have the very bottom end of the EQ bumped up a TINY bit, and it's just about right for me. I'm not really a bass-head. Bass is, to me anyways, often distracting from the delicious detail in the rest of the scale.
It's hard not to gush about these headphones. They're great. I'm probably going to eventually move up from these, but something tells me anything above the 650's will suffer from diminishing returns since the 650's seem to be at a good price point for the performance you get.
And everyone who owns a pair already know all of this about the headphones. This was more of me just contributing to user impressions for future owners who're searching for this sort of stuff.
ASUS Xonar Essence STX > Blue Jeans Digital Coax Cable > Schiit Bifrost w/ Uber DAC Upgrade > Blue Jeans Interconnects > Schiit Lyr (Russian tubes) > HD650