Just bought myself Rokit 5 (powered) monitors to use on my laptop and plugged them into my mixer via XLR (from Rokit) to quarter inch cables TRS into the Main output of my mixer. I have the Behringer 1202 mixer

Plugged into my comp using the normal red/white cables into the appropriate place. My result was the sound playing very low and unable to turn up the volume. When I did try increasing the gain on my mixer, the only volume that increase was this hiss noise.

I just thought, its a old mixer and its probably broken or something. Just got back from guitar center and bought a brand new Behringer 502
Pretty much the same with less inputs. hooked it up the same way and i'm getting the same exact problem..

Dudes at guitar center said this mixer was fine with hooking up monitors and the Rokits are powered so they dont need any additional amplification. . no idea what's going on and its frustrating.