| No, not the plugins.
If it sounds right when played in your DAW, and it doesn't after being bounced to 2-track, there must me something wrong with the export settings in your DAW. (at least, that's what feels like logical to me) So we're (I'm) interested in those settings.
And, again, the mix is not mono at all, it's just very narrow.
@alehoe: what's the difference between 'normal' and 'joint' stereo in this case?
Edit: saw you added info about the export settings. Is the mp3-converter part of your ProTools workflow or do you apply it afterwards? |