I'm trying to record both what's happening on screen and the audio being played by the applications. To my surprise, QuickTime did not record the sound. I believe it worked before in previous OS X releases, but that is not something that I use often so I have not bothered to try earlier.
What is the current situation on El Capitan ? Have I messed with something that prevents QuickTime from capturing the sound, or has it never worked ?
Here is my view of Quick Time / New Screen Recording on a Mac Mini:
On my Macbook Pro, I have the option select None or Internal Microphone. Internal microphone actually records the speakers of the Mac Book as heard from its own microphone, which obviously sounds terrible.
This is a MacMini 7,1 (late 2014) and there is nothing in Input Sources.