7.1 Surround sound problem

Hi! 1 year ago i bought Razer Headphones, and in box there were a 7.1 Surround code that i have activated, and all was fine until a few days ago i saw a big problem: When i’m having a «Speakers (7.1 Surround Sound)» output, the sound is transmitted with glitches, BUT (!) when i’m having a normal «Headphones (Realtek(R) Audio)» output without 7.1 Surround Sound, i don’t have any glitches. Don’t you know why is this? I really want to play games with 7.1 Surround Sound, but not with glitches. If there is solution, please let me know and write down below . Thank you so much!