What I do notice on my HE4 is that the Mixamp+E9 has like literally no hiss. I've only experienced that with the HE4. Everything else has hiss.
I have zero issues.
OH YES, try it without the Y cable/mic and see if it still sounds bad. I had ONE occasion where doing this really effed up the sound. I took out the Y cable and the problem went away.
I'm not the only one to do this setup, but you're certaimnly the first that has complained about it. Dunno what to say. All I know is that it should literally add or take away nothing from the Mixamp's sound. Positioning, directionality, everything sounds the same. Even did it with my easy to drive cans. NO issues. I'm quite anal about my game audio, so saying that there's no issue, I mean it. The E9 literally is just a needed volume boost/amping for hard to drive headphones.
Again, this is for CONSOLE GAMING. I can't guarantee anything on PC. You might wanna try another cable... if not, you're SOL. I enjoy my HE4 for gaming with this method, and have zero complaints. They are stellar gaming cans.
Edited by Mad Lust Envy - 6/17/11 at 2:57am