[AtomicAnt]

Hello guys'n'gals! newbie here!
 
Recently I have purchased these Denon AH-GC20 headphones and now Im having a strange feeling. When I was trying them with my iPhone6s via BT and wired they sounded (and they still do) pretty good. But when Im plugging them into my PC... all i hear is bass... Its like the only thing that is there on the stage is the BASS! All mids and highs seem to be somewhere there but far... far away.
 
Now...My PC has an ALC1150 (Asus X99 Deluxe) audio chip and I've tried and installed different players and equalizers and I've tried to tune them in accordance with my iPhone's eq settings, but none of them seem to help much.
 
Please don't throw rocks at me I was looking for decent BT/Wired headphones and my choice was either Sony 1ABT or Denon AH-GC20... and I've chosen the latter because they were the only ones available for try-before-you-buy
 
So, what do I need to make them sound right using my PC and cable? another headphones? a better soundcard? another head? better ears? an amplifier? Im out of ideas. That's why Im here
 
Thank you
 
P.S. Of course you can throw rocks at me I'm a newbie after all