There is a known issue with SMPX export from Finale 2014.5 on Mac that causes about 20 seconds (time varies) of silence prior to beginning playback of the file in SmartMusic. Our Developers are aware of this issue and will be working to fix it for future versions of the program. There is a workaround for the issue that can be used for the time being...
- Open the original Finale file in Finale 2014.5
- Click MIDI/Audio > Human Playback > None
- Click the MIDI Tool
- Click MIDI Tool > Apply Human Playback...
- Select the Style you would like to define and click Apply
- Click Close
- Export the file to SMPX (File > Export > SmartMusic...)
This should create a normal SMPX file with all the Human Playback settings applied to the file, but without the errant silence.