Solved Game Audio Crackling (and crashing) - Constant Static buzz

Hello! I saw plenty of helpful replies here so I was hoping you could all help me with my issue.

System Specs:

Processor: Intel i5 2500k (o.c. to 4.2 GHz)
Mobo: Asus P8Z68 M-Pro
Graphics Card: ASUS GTX 680 superclocked edition
Soundcard: Asus xonar DSX 7.1
PSU: OCZ ModXStream 700W 80+ certified
OS: Windows 8.1

Keyboard: Corsair k70 RGB
Mouse: Razer Mamaba 2012 Edition
Headset: Razer Tiamat 7.1

Background information:

I've noticed recently that there is plenty of audio buzz/crackling in my headphones when I'm doing nothing intense. It's not super intense so I thought it may just be because of my headphones (Razer....). But it seems to always be occurring. I did some research and I noticed that the USB used to power the headphones should be plugged into an external USB power supply. No luck there. I left it for a while but more recently I've been having even weirder audio issues.

A long time ago I bought hitman: Absolution (IIRC I was on windows 7 at the time). It was playing fine at the time with no issues. Recently there was a humble bundle for Hitman: Absloution and that peeked my interest to go and play the game again, only this time when I went in all of the audio in the cutscenes was lost and the main menu audio was messed up. Hovering over a menu button caused a popping sound. This is the first instance of weird audio/game bugs. However once i get past the main menu and cutscenes the ingame audio is fine. So I thought this may be due to the games integrity, but steam said the files were fine.

The next strange, and more annoying bug I've recently encountered is regarding terraria. First I should say that about 1 month ago I was able to play Terraria fine. Now I should mention between the last time and this time, the only things that changed on my system were: Graphics card driver update and Corsair K70 RGB keyboard (from Razer blackwidow). Yesterday I went to play terraria with my friend and I would get about 3 FPS in the menu if I was lucky. Sometimes the fps would go up to about 60 FPS for like 3 seconds and then the game would lockup for a minute or so before allowing me to move the in game cursor again. I was never even able to make it past the main menu. Hovering over a menu item it would cause the audio to sound "Laggy" and by that I mean as if the sound was playing over a couple of seconds being chopped up and popping in and out. (hopefully that makes sense).

Finally the last and weirdest issue. My new keyboard has the option to change the LED colors of the keys. I noticed when I change the colour of all the keys from blue to red lets say that the static noise in my headphones changes, it either gets louder or quieter and crackles more or less.

What I've tried:

I use the unofficial unified ASUS Xonar drivers: UNi Xonar Drivers official page - MaxedTech I've been using these drivers for the longest of time without any issue so I do not believe they are the source of the issue. I ran a CCleaner registry clean and system clean. After that I ran the "sfc /scannow" command and it did not find any issues. I've tried disabling Nvidia Shadow play. I tried uninstalling and re-installing Terraria along with all of it's components (.net 4.0 and XNA).

What I plan to try:

1. Try a different keyboard
2. Roll back video card driver (Is this even possible?)3. Remove the sound card and revert to onboard sound (just to see if that is the issue)

Solution - Reformatted PC and it works again

Thanks in advanced. Let me know if more info is required.

Fixed it by reformatting -- Guess the time was due