First off, you don't need that expensive of a sound card for those headphones...not in the slightest. An Asus Xonar DG would be fine with the Razer headset if that.
Second, Razer headset is just bad for actual audio quality
Third, 7.1 on a headset is a gimmick, it's pretty much impossible to get 7.1 in headphones. I have heard they do exist but they cost a lot of money and I know for a fact Razer is not one of them.
Fourth, the mic's on these headsets are cheap, you could get the same quality from a $5 logitech.
Fifth, you mentioned beats and good in the same sentence...Ultrasone HFI-580's blow them out of the water at close to half the price.
I would recommend returning said items if you are able and doing some reasearch.
The Dr Dre Beats are good for music on a ipad, iphone or laptop and thats my opinion i know there are better headphones out there and im sure i would only be able to buy them from a hifi shop not the local electronic shop or computer store.
I cant see how its a gimmick the 7.1 its says its the worlds first 7.1 headset set. and when i done the setup test i could distinctly hear the different drivers and you can see them too. but i do understand the drivers and the rest of gear is not the best but there is not any other true 7.1 headset available. so what do you do if you want positional awareness with gaming and not rock the house to death.
I have a Sony Muteki 7.2 hifi system is that any good? it cost me 900 aud and more than happy with it. i went to a hifi shop near me and they put a 5k hifi setup on for me and there is no comparison the 5k smashes mine and even sounds better than my local cinema lol. but where do you draw the line?
So you know what i have recommend the best headset for me. I dont care for music or movies on my computer.