Ok this is my set up. Mac Notebook 13.3 inch 2.2GHz 2GB 120GB Core 2 Duo Processor Behringer EURORACK UB1202 12-input, 2-bus mic/line, 4 (IMPs) 3-band EQ. Logic Pro 9 and Garage band. No matter if im recording or just have my headphones on setting up a channel, there is a constant buzzing or hissing going on. Ive used compressors, limiters, de essers, de-noisers, everything you can think of and nothing seems to be working. Can someone please help!