Hello TGP, new poster here! I apologize if this has been asked before but I was wondering if anyone has had a chance to compare these two side by side? Using the same settings on my HD500, I compared the K8 and K12 today (the store didn't have the K10) and the K12 sounded significantly louder. I'm not sure why that is since they're both 1000w. The K12 also seemed to have a little more bass though I was impressed with the bass response of the K8. Is the K12 also louder than the K10? Any other differences? Thanks!