FPS Gamers, here are my results. My 3 headphones, k702, HE4XX, and AD900x have arrived. Please note that I am running them without an amp yet out of my laptop's built-in audio chip.
Game: Battlefield 1
Windows Sonic for headphones: ON
In-game settings: Headphones, Surround
No external AMP/DAC in this test
1. Imaging Short Range: K702 = AD900x = HE4XX
2. Imaging Long Range: K702 > AD900x > HE4XX
3. Separation of sounds: K702>HE4XX>AD900x. K702 has the cleanest distinction of sounds. AD900X throws all sounds at you in one lumped up package; sounds like a dirty mess.
4. Sound Stage: K702=AD900x > HE4XX. The AD900x has a hollow sounding stage, you can hear the air, hear echo, hear the emptiness, not clean.
5. Sound of my gun: Loudest and most immersive on AD900x, balanced on K702, acceptable on HE4XX.
6. Sound of footsteps: In BF1 is very low on HE4XX, not competitive, makes me lose. Will an amp improve it or should i use EQ to better hear footsteps (which frequency?)
K702 is clear winner without any amp. Wallhack can.