All I'll say is, I bought the Impact for the sound blade(the included sound "card" they give you)and today I'm returning it. It's garbage for driving good headphones. You can't use the rear line out if you have decent headphones because they blew it on the design and only dedicated one amp to the rear out. They gave 3 amps to the front panel audio which is retarded in my opinion, so you have to plug in that ugly HD Audio front panel header and use the front jack.
Once you do that, you can get access to amplifier settings in the garbage skinned Realtek(themed in red/black RoG skin)control panel, however changing the amp setting to anything other than what it defaults to doesn't do anything and there is no indicated fix coming. The sound card can barely power my ATH-M50 headphones.
Let me just say that between my X-Fi Titanium and this PoS, the X-Fi is astronomically superior in every way and I'm glad to be using it again.