I am having the same issue as Ollie.

I can’t get this to work for an MP3 stream. I was able to get it working with a static MP3 file stored on my server. This problem exists only on Safari.

createMediaElementSource() seems to be buggy in Safari. Specifically, the frequencyBinCount() returns just an array of zeroes.

Is anyone else experiencing this? I will try using the adapter.js shim, but I was hoping for a native Safari solution.