zazex
Headphoneus Supremus
It's quite easily actually. From my experience in particular, I had 3 years of Planar Magnetic listening that my ears were accustomed to. The closed, resonant and high distortion of the bass of the Z7 was an instant alarm when first hearing the Z7. I'm sure you could picture how stark of a difference that is, when you're used to linear bas with no distortion and fast decay of an open planar for so long, and you go right to the Z7.
I really like the Z7's bass response.
However, I do have a lot of experience with Sony headphones, and their new house sound in particular. So I'm used to this kind of sound.
Going back to a planar magnetic like the Oppo PM-3 is a downgrade for me!
Edit: I you have ever heard the Sony MDR-10R with that extreme bass response, the Z7's are very neutral. Also, in comparison with the Fidelio X2, the bass is better on the Z7. And the soundstage is more or less the same, and that for a closed headphone! It's quite something.
I also think that Sony did a great job with the Z7's bass.
IMO bass is not "better" solely because a driver is planar.