AKG K701/2, K712 and Beyerdynamic DT990 gaming comparison.

[EsaT]

If I was to go for something like the AKG702's do you think I would get the best out of these running them with 5.1 surround, or using Direct HP (stereo)?

My only gripe with the card is that Direct HP is the only way to set the headphones to stero but as a result this disables everything, for example the equalizer

K701/702 are among absolute top headphones for gaming with binaural sound.
If game itself has good sound engine you could pretty much locate other player walking inside smoke (using it as cover for getting close) well enough for decent chances to hit him by "spraying" that direction.

Disabling Surround and any unwanted effects and at the latest switching Windows Playback configuration to 2.0/stereo gives stereo playback.
If Windows audio stack doesn't do own "upmixing" you could leave Windows Playback setting configuration to 5.1.

 

[EsaT]

How would these stack up against a a pair of Sennheiser GSP 500s?

I'm assuming that a pair of 702s and a mod mic would be the better option (I plan on running them for the time being off the on-baord audio from a Asus Crosshair VI).

As closed design those have likely not much of chances for even half the sound stage of DT990.
And that's generous estimate.
For standard closed design gaming trinket its this: Head in bucket under water.
Superlux HD-330 whose sound stage is step below DT990 sounds like top level headphone compared to typical cheap closed stuff.
So even if directionality works you won't get much depth/distance feeling.

Asus has its Sonic Studio which should have some kind binaural simulation.
Just haven't found really good comparisons videos.
Though I guess it should avoid Dolby Headphones strong echo.

 

[EsaT]

I was slightly concerned by that, I have a couple of pairs of headphone break where the overhead band meet the ear cups and don't want to buy an expensive pair only to have the break after a couple of months *cough TurtleBeach cough*. I was looking at a pair of DT990s as they have the a similar headband system to my current QH-90s, but i'm guessing i would need some better way of driving them than the motherboard's onboard amp.

If having bigger head automatic adjustment of AKG can certainly stress those elastic straps/rubber strands.
Though overall design is better than in Sennheiser HD5xx serie.

Beyerdynamic again scores really high with that simple and robust design with lots of adjustment range.
Which also keeps cups well positioned, if having smaller and downward narrowing head, in which situation AKGs might try to slip down.
Just like Superlux HD-330/660 those Takstar made QH90s seem to have little smaller headband than Beyers:
https://youtu.be/wyXiW77qve0?t=4m44s
QH1339 is custom coloured MMX300 which is DT770+mic.

250 ohm Beyers are actually easier to drive than AKGs.
While they need about same amount of power they draw lot less current lowering stress on output.
Something like 30% volume setting already gives good volume.
I once tried that with very basic motherboard with ALC892.

 

[EsaT]

It is funny how I’ve read so many people across many forums how they don’t like their sound signature. I thought they’re fantastic. As it seems most people are bass thundering junkies.

The other great thing about them, they’re so light you don’t really become aware they’re on your head. Sometimes they remind me of the days being a child wearing earmuffs during the winter.

I guess most consumer stuff is seriously bass heavy with bad everything else.
So when headphones have actual mids and treble people think bass is bad.
I mean some say even DT770 isn't bass strong!

Any headphone you don't keep on head even when not listening anything lacks comfort...

 

[EsaT]

Would x-fi surround 5.1 usb pro with a magni be alright for testing? (with cmss-3d headphone)

Despite of that "X-Fi" sticking in there X-Fi Surround 5.1 Pro comes with SBX Pro Studio software.

Old genuine X-Fi/EMU20K chip based card would be likely only way to get CMSS-3D algorithm.
(or Audigy Rx)