You can't use both.
In Primus you can select only one transformer, listed above by V1, but if something doesn't work, you can just switch it with a single line of code. No rewrites, no need to learn a new API.
This is not a bug in the library, it is a browsers security feature. Audio files can only be played from the same domain that you are trying to play them from because an XHR request is used to fetch the audio file.