weird audio noise has nothing to do with dropped frames. I don't know what your problem is, but it has nothing to do with your drive arrays.
Apple ProRes422HQ requires about 30MB/sec from the drives, which even a single modern SATA drive can do. Two stripped RAID 0 will give you about 120MB/sec, which is more than enough to do ProRes422HQ. Your audio noise issue is an unrelated issue.
So now your question is "why do I get this weird audio noise when I edit in FCP ? ".