ok i bought a used 2006 macbook pro a while back, works great except for the internal speakers, ear buds, usb external speakers, aux jack plugged into stereo speakers. ive tried everything i can think of to fix the really low volume, everything ive found on the internet for fixes. so i tried the audio hijack software, hey it really boosted the sound, and quality isnt to bad either. just wonder if it can hurt anything using it. also does it affect the ear buds or external speakers in any way. if i were rich id send it back to apple to fix, but not.