I came across this thread because as an audio guy who is only getting more into video, I know that my .wav files are the best. Upon import though, I have had to bounce them as .aiff files instead because once I put a .WAV file in fcpx it distorts across the entire track. I tried different sample rates and nothing would fix this. I cannot figure this one out. I keep finding other FCPX bugs the more intense projects I do.