Thanks for the comments guys!

@ Phil: I don't remember exactly, l think I used "aspect ratio" limit with "avoid smaller than".
I remember trying a couple of combination to get the right size/detail ratio.
Just one side of the microphone screen is a 27mb 3dm file!

@Micha: 5min for the first, 15m and a half hour for the last one, close-ups with dense mesh tends to take longer.

Marc