Can you share some of those WAV-files? Maybe then it becomes more clear what the problem actually is.
When you import samples for the creation of soundfonts, you have to know:
- Polyphone reads WAV-files and FLAC-files with a bitdepth of 16 or 24. 32bit floatpoint or anything else than 16bit or 24bit cannot be read and imported.
- 24bit audio automatically becomes converted to 16bit audio, despite the support of 24-bit audio with the 2.04 SF2 standard.
- Polyphone can import FLAC-files. Beware the FLAC-format doesn't support the storage of loop-points. (So before you want to convert WAV-files to FLAC to save data-storage you have to write down the loop-points somewhere, so you can insert them again after importing them into your soundfont
- Multiple loops can be stored into WAV-files, though Polyphone reads only one loop (one start point and one end-point).
To find out if your WAV-files contain multiple loops you can use free software such as
Ocenaudio or
Wavosaur to check that out.
When you use Windows than
foobar2000 is a good application for converting audio-files. For that you need to install the
FFmpeg source code as well.
Fre-ac is also a good application for that and can be installed within MAC-OS as well.