These sound really good out of the box.
I've used Grado SR225 for almost 9 years now and they have been my reference headphones.
I'm trying to find a place for my Grado's in a specific genre where I would prefer them to K7XX but so far I can't.
Sound Stage
-The sound stage is not as great as my brothers K701 but still pretty good.
-Better then Grado SR225 hands down.
Ease of listening
-They are also not as analytical as K701, so easier to listen to for longer period of time.
-I can listen to these and Grado SR225 for a very long time at moderate volume level.
Comfort
-More comfortable then my SR 225 because of the soft ear cushion.
Sound Isolation?
I can't hear as much outside noise with these as I can with the Grado SR225.
-I had my brother come in today and I didn't hear it at all with the K7XX.
--Never would have happened had I been listening to my Grado SR225.
--The Grado SR225 are great if I need to pay attention to my surroundings and want to enjoy great sound.
Bass
-Better then K701
-Better then SR225
-Not as good as M50x
--M50x is a closed can, the AKG K7XX have a nice bass feel for open cans.
Rattling issue:
Rattling Issue confirmed on right side
Left side is at
(~80% Fiio e12 & 85% Windows Volume)
Right side is at
(~80% Fiio e12 & 60% Windows Volume)
@ 60HZ and 70HZ
https://www.youtube.com/watch?v=E_Sf7rSOU78
https://www.youtube.com/watch?v=7VQ_vtFkXHk
-Normal listening is at 80% e12 and <10 Windows Volume
-Max I would ever listen to is at ~50 Windows volume for only a few minutes at a time...
I think it's fine though, I tested my Grado SR225 at similar volume at those frequencies and also I get rattling sound.
I guess any headphone is going to start rattling at enough volume.
Only real issue I find is that the right driver is weaker then left driver.
These are a very good value @ $200 USD
Update-
When I said right driver is weaker then left driver
I just mean that rattle starts on right side easier then left side.
I did not mean that right side sounds quieter. So far I have not noticed any sound imperfections at normal listening levels.
The volumes at which phones started to rattle are pretty high. I doubt I would notice any rattling even if I was listening at ear bleeding volume. Unless the song is entirely in those low ranges there should not be a problem.