Export file in H.264 and upload to YouTube --> Audio overdriven and too loud

Hello,

when I export in FCPX a video with the integrated H.264 exporter and load this video up to YoutTube, the sound will be overdriven, too loud and not usable anymore.

I level the loudest sound in FCPX shortly before 0 db (-3db) with a headroom of nearly 3 db.

I know that YouTube change the video and audio file and that it gets louder. But here is the difference 6 db! In FCPX I have to level the sound know to -6db to get a working video in YouTube. This is strange because the same project edited in FCP7 with the same audio file, leveld to 0 db works fine in YouTube.

Another strange thing: whe I export the video DIRECTLY to YouTube without the step of exporting into a vide file, it works fine!!??

I don't understand...

-6 is where digital video should be. FCP 7's meters weren't that accurate. And look very closely at FCP X's meters, they show way more above 0db than FCP 7 did. I have seen folks "assume" things until they actually look at the numbers on the meter. You shouldn't let you audio get anywhere close to 0db, actually. Never let it go over -3db mostly.