I want to get rid of FMOD in order to ship games on Linux as the FMOD indie license only allows 1 title per year after which you have to pay $500 every time. I tried searching on how to swap out FMOD in favor of OpenAL but with some experiments in the CMake configs it doesn’t seem possible to do in linux builds?
I’m not much of a Linux build guy, but after some trial and error I was able to fully remove FMOD from cocos2d-x. I did this not because of the FMOD license, but because I’m not using CocosDenshion or the new AudioEngine at all. (Both exhibited issues for me in win32.) I’m now using SDL2 for audio across all my desktop platforms.
So, while I didn’t find it easy to do, it is possible. Good luck!
It would be extremely helpful if you could write a short tutorial or even just dump the (diff) CMake files you used to do it. 
I’m sure I can figure it out but as you said it wasn’t quick/easy so I’d love to save some time (and I’m sure there are others in this condition)
I don’t think I could write a full tutorial. Can’t remember everything I did! 
In short: I searched every file for FMOD and remove every reference I found.
okay thanks for the information, I guess I’ll have to hack at it myself 