In X3
If bouncing tracks to a new track (combining tracks together) ...
1) In the Track View select the tracks you wish to bounce (highlight the track numbers of tracks you want)
2) In the "Tracks" menu above the Track View select "Bounce to Tracks"
3) In the dialogue box that pops up, it will default to the next empty track number
4) In source category Channel Format of "Stereo" will give you one stereo track, "Mono" will give you two tracks (L and R mono respectively). Choose options you want, and click OK.
5) You will get a new track from the selections you have chosen
To export audio is similar... you
must chose the track(s) you want before opening the export dialogue...
1) In the Track View select the tracks you wish to export
2) File -> Export -> Audio...
3) A dialogue will open allowing you to name the file and select option you want. Select these and click "OK"