Case - Fractal Design R3 Motherboard - MSI P67A-GD53 Graphics Card - Sapphire 6850 HD Dirt 3 Edition Sound card - Asus Xonar DX The problem I am having is as follows: The microphone works perfectly until I launch a graphically demanding game. At which point the microphone data my friends are recieving starts to buzz in Mumble and TeamSpeak. It sound like a small scooter engine! I can hear no issues at my end. I am attributing this problem to EMI either created by the twin mounted fans on the graphics card or the large amount of current the graphics card is using which is creating the interference. What I have tried so far: 1. Having moved both cards the maximum physical distance away each other, there is still a faint buzzing. It is impossible with this particular motherboard to move the two cards any further apart. 2. Enable AEC in the Asus Audio Centre software. Makes no difference. 3. Ensured the on-board sound is disabled in the BIOS. 4. Tested the on-board sound, which is working correctly with no buzzing for the receiver on the MIC. Can anyone give me a cost effective solution which will enable me to continue use both the graphics card and sound card I have listed above? I realise that what I have made, is a poor buying decision. In hindsight I should of purchased a shielded sound card but I had thought the Asus DX was suitable for a moderate gaming rig? Thank you for your thoughts and suggestions in advance, Steve.