I went back to Cubase and got a wav file of the song. Put it in Flash. But when I export to a Quicktime mov
file the sound quality is still bad. It sounds very sibilant. Sounds great as a fla file. I set the properties as they should
be for export.
Sibilance would be noticeable if you were using the default settings of MP3, 16kbps. In the dialog I showed, you would need to set both Event and Stream audio like that, to make sure you're exporting both kinds in good quality:
Also, checking the Override box is worth doing, in case you've already set some sounds in the library to be lower quality.
When you have done the export, are you listening to the MOV file, or are you sending that to Adobe Media Encoder to make an MP4? If you are, what are your compression settings like? If your plan is to do more work on the export in Premiere or After Effects, and if you're ok for drive space, you should use the MOV version in the other program.