[DUPLICATE] external audio sync beep

[sim]

Hello Everybody,

would it be technically possible to send out a short and loud "beep" via the built in speaker, maybe one second after hitting the record button to have a precise sync-point for external sound recording?
This might replace a slate in some situations, if the camera and the external recorder would get the same specific sound at the same time. It would be easy to sync in postproduction.
And maybe there could be another "beep" at the end, when you press the button to stop recording. Could help to check if there is some delay between the two sources.
And maybe, only for this specific frame the iso could be altered in order to have a bright or dark frame with the "beep". This could make syncing faster.

Thanks for your work, Sim

[a1ex]

Duplicate of http://www.magiclantern.fm/forum/index.php?topic=1438.0 .

[Tired2]

I'm not sure this was a duplicate of the linked post.

What he suggests is a beep (probably out of the camera's speaker) that will reach both the internal mic and the external recording mic at the same time to help sync up the audio in post.

Maybe I need to read more on the mic power setting in ML, but they seem like different things to me. 

I could see a certain frequency beep being found by some post processing software in both audio tracks to give you the precise offset to set in the sync software.  I do not use an external mic currently, so I'm not sure what the other "easy" methods of syncing. 

[a1ex]

I see both of them as some sort of solution for audio syncing, so to me it seemed more appropriate to be discussed in the same thread.