HELP! I have Final Cut Pro and overtime i upload it to youtube the sound is distorted?

I have Final Cut Pro X the new one that just came out and every time I upload the video i am doing to youtube it sounds horrible and distorted like my speakers blew. But when i play it in FCP or on the video that i exported directly to my mac it plays fine. Has anyone had this problem? or have a solution? I love this FCP but this issue super sucks! Thanks!