There's no need to "chime in", the only logical explanation is K267 is vented while K167 is fully closed, alpha10, maybe you can look for where the openings are positioned? Maybe the at the "ring" at the adjustable bass setting or maybe on the outer shell somewhere else?
The bass adjustment is like earlier said 99% likely down to how much it's vented (more venting = more bass = less isolation).
However I would be suprised if alpha10 doesn't notice an even better soundstage on K267 as a result, from my experience vented cups always beats fully closed design (if all other factors would remain the same, ie same design, drivers etc) and now the cups are exactly same shape so the vents should show their advantage in a better comparable way. All headphones I've tried with openings in the cups gets significantly worse soundstage if covering up the openings.
Would be nice with a more detailed sound comparision as I doubt it sounds exactly the same due to vented design and different drivers (40mm vs 50mm). Getting the same frequency response out of different drivers, especially when different size, is already a big challenge.
EDIT I'm guessing the openings are probably around the "turning circle"
Probably as you turn it, new opening(s) are exposed which you can easily determine if putting the ear next to it. It should be of a more bassheavy sound leaking.
