Reply to S4 pops and drobouts, please help!!!

My problem is that my S4 makes pops and drop out sounds all the time!

I just started up my S4 up, after a year with not working on my HP envy15 at all (the pc is not what i want to DJ with and its very bad, i tried to fix it but cave up after 2 months), but with my dads Mac book pro 15" i7, i just tried today, but now there is a new problem; when i start a song i hear massive pops and dropouts in both speakers and headphones, this does not happen when i use the built-in sound card.
The controller itself works fine and can communicate with the computer. I have tried working on the latency in tractor, but its the same on all Hz and all the way down and up... i'm really lost..

I'm using T2, some cheap headphones and a set of 240w speakers with phono lines.
please help, i am very desperate to get it fixed!