I don't recommend using Sine intensively : you will break it.
I don't expect mine - used VERY carefully- to last for more thant 2 years. This is the most fragile headphone i ever owned since over 40 years. INTERNALLY AND EXTERNALLY.
Using Sine with a phone means while stressing i.e. : you take them on and off to grab papers ... you will very soon destroy them.
Using Sine while walking is also a non-sense : they are not stable on you head and when exposed to external elements ... you will very soon destroy them.
Sine are dedicated to sedentary use - as they are small you can bring them with you while you travel providing you buy yourself a proper travel container like i did.
When I unpack and start to work they are -together with Conductor Air - like being at home listening my larger HiFiman 400i on my larger Burson Conductor.
I know Sine have been designed to become the light portable version of it's bigger brothers. BUT they failed manufacturing a robust yet high quality portable headphone.
Such headphone does not exist on the market. Oppo PM3 are lifeless and awful treble. So i use different headphones for different circumstances.
BEYER T51i is the one that is the most versatile : for the last 2 years i used them for music and phone nearly everywhere and they are still intact almost like new. I certainly could not achieve this with Audeze Sine. When taking a plane nothing better that Bose QC15 noise cancelling.
I like the audio quality of Sine ( not as good as my Hifiman 400i but close ) I thing they have no competition in the category of small transportable headphone. But I am sure someone will do better and more reliable soon. I am expecting Oppo to better its PM3 series ...the trick is just a little more life and a better treble...
You know, I really don't want to agree with you. However, with a certain amount of regret, I do.
I've bought quite a few audio and headphone related items this year, and, despite the SINEs overall sound quality (assuming you keep your head still), quite frankly it is the worst purchase I've made this year.
Basically since June, they've been sat inside the EL8 case. Essentially they have too many problems to be of use to me in any of my normal headphone listening situations.
Ok, there's no doubting the overall sound quality of the SINEs, but I really don't like it when the volume and left right balance briefly changes every time I move my head. Then there's the slight crinkling sound that accompanies that. Add to that, that they're all but useless on my commute due to the lack of isolation - I have to put the volume up so high to overcome the ambient noise that I fear for my hearing.
I guess the problem is that I have is that I have a number of other headphones at around the same price point, or considerably cheaper, that either have a better sound quality, or they are not very far at all behind the SINEs in terms of sound quality, but simply work far far better in environments where the SINE just falls apart.
I'm known as a bit of a headphone junkie in my circle of friends and I've been asked a couple of times if I recommend them, and my answer has always been that even though the sound quality is good, I cannot, in good conscience, recommend them because of all the other issues that they have, especially given their price point.
All in all the SINEs have been a somewhat of a disappointment for me. However, having long since forgotten cost, I'm not upset or angry as I fully accept that sometimes in this hobby you'll end up buying a duffer, and at least the SINE is a relatively good duffer.