Well, these are my first owned open back. There was none before, because - a) I listen at office, b) I listen in non-quiet room (I have 2Y old daughter), and c) I was very satisfied with Oppo PM3, V-Moda Crossfade, and Sony WH-1000XM2. Then one day I decided that if necessary, I will reserve some empty room in my university and I would listen HD 6XX, and I would definitely listen to it. But a little problem was its high impedance and lack of a good amp. I have only FiiO Q1 MKII and E11K. And right then I discovered that there is a sibling exists and it is HD 58X - with half impedance. I heard that there was differences but they have their own pros too.
So, I ordered it and received via third party shipping (Sennheiser doesn't ship it to Singapore or other Asian country). My first impression was - "WoW! What am I listening, too... everything is so natural!!" Music with acoustic guitars are simply amazing.
People complains its treble. For me, its treble is super smooth. No harsh point at all and simply comfortable. It may not be super critical but super enjoyable. I want to say, it has most natural sounds for all kinds of instrument including all kinds of percussion I know. They are definitely airy, too, for being open back.
Bass is exactly the right amount to be both fun and natural. It is punchy that I enjoy very much and very deep. But of course not bloated at all. But with some music with lower quality recording of current pop genre, bass is lacking and not good.
Vocals are delicate and just amazing, too, I should say excellent. But I enjoy more with Westone UM PRO 10 (2G) for that.
Imaging and soundstage:
Imaging is definitely excellent. But it does not have space around the head - I mean I expected more soundstage but at the same time it may have destroy the intimacy of the vocals. Is there a headphone that moves instruments far away but keeps vocals really close (with price below $300)? For that purpose, I ordered HE4XX and waiting for delivery.
Usage, Isolation, Leakage:
Oh! in reality, I use it both in my office and home. In my office, I listen lowering the volume and it does not leak (despite of being open back) enough to even disturb my closest neighbor colleagues. Moreover, at low volume, it is still enjoyable and clear unlike my other headphones. Funny that I have even use it in bus, and it sounds just fine - very natural - like - "I am in a bus and also listening some musics" - not like "I'm in an isolation chamber" (very untrue) with WH-1000XM2. Treble is clear and bass is enough to be heard in this situation, too. In home, I use it when everyone sleeps for critical listening. When they are awake, I still use it so that I can also listen if my wife and baby is calling me. With low volume, I can also listen to my wife without pausing the music. That gives me a very natural life.
- Xiaomi Redmi 4 Prime needs 70%-80% volume and still not very crystal clear but enough for casual listening.
- IPad gives better sound with these with 60%-70% sound. Better DAC but low in amp.
- My PC - Acer Aspire S13 can deliver enough power with 40%-50% volume. High on amp but not a very good DAC.
(None of them are for critical listening - bass is a bit bloated and treble is not very airy and sharp - an amp is necessary with a DAC)
- FiiO Q1 MKII is enough for crystal sound with 50%-60% volume. Very nice sounding.
- E11K is just fine and requires only 25%-35% of volume.
Build and confort:
Its build is solid. I do not care much if my daughter play with it - tries to wear for fun.
Initially it had some clamp pressure, but with a small mod, it is very comfortable now.
I enjoy it so much that I do not use my closed back and wireless cans anymore.
If I use them, I come back to it soon. I just find myself inside a waterfall.