I use Firefox Quantum 62.0.3 (64 bit) on OSX 10.9.5 Mavericks, mac mini late 2012, I7 quadcore, 16GB ram;
This morning a colleague of mine at school tried to open the app on a macbook pro running OSX Sierra and a message appeared: "Audiotool only supports Chrome"or something like that; I could actually run audiotool on Chrome but my cpu suddendly warmed up until 100°C and activity monitor showed a 450% usage... (I wrote another post about this...)
I'm afraid I'll leave audiotool aside until they won't fix this issue... :-/
I have the same heckin problem