muffled sound after exporting project from FCPX to QuickTime

Hello,

I have searched for an fix everywhere but can't find any solution. I really hope someone here can help me.

I have produced a song myself and now want to add some video clips to it and later upload the final product to YouTube. The music file I have imported to FCPX is 48 kHz, 16bit Wav. Everthing sounds good in the FCPX timeline. Also, the music file sounds good in iTunes.

The issue happens when the final product is exported from FCPX. After the export the sound becomes muffled. Also other things happens to the song. For example: In the intro I have an snare rolling. In the end of every bar I have a harder drum hitting. When that drum hitting, the volume of the snare is going down. That is not happening in iTunes. This destroys the sound and is a bit frustrating.

I have tried to export with all different settings I can find. The same issue occur in iMovie.

The sound level is not above 0db and are never in the red peaking area in FCPX.

I have also tried to put the level as -12 db and export the project. The overall volume is after that too low and the issue still persist.

Hope anyone out there have an solution.

(Sorry for bad English)

kind regards

Jonas