hi there! i have a pentium 4, windows 2000 xp pro, onboard sound card Realtek AC 97. i'm using a Dj music mixing software called VirtualDj. i have a splitter connected to my line out, leading the sound both to my headphones and to a stereo amplifier. when i try to use the "pitch" option - instead of making the wanted differentiation between the headset to the speakers - all it does is splitting the sound into right and left speakers/headphones (which means i can hear 1 track in the left ear/speaker and the 2nd in the right ear/speaker). what am i doing wrong? or what ain't i doing? also, soon i want to upgrade myself to a laptop. what should i concider, when i'm looking for one, regarding the same issue i mentioned (model, processor, memory, sound card etc.). THANK YOU.