Hello Sebastian and welcome to the Cow Audio Forum,
Ray’s right about wireless and hard wired. If the room is filled with cell phone, Blue Tooth, Blackberry toting folks, you can end up with swiss cheese for audio if you try wireless.
If you can get every one to power down (and not just go into standby) you may have a shot.
I like to mic presenters with a Countryman e6 and go wireless or hardwired to a mixer that feeds the camera or recorder.
Mic on the ceiling….hmmm well depends on how high the ceiling is and the ambient noise level. You can hear what I do by downloading the mp3 files in a folder called IPS on my Online Archive. These files have been processed to sound LOUD.
There are main and Q&A sections. That’s a 20′ x 40′ room with 8′ ceiling. On the main lecture, there’s an intro (ceiling mic..and getting them to stay under it is difficult.) and then the main speaker talks. He’s on a wireless Countryman e6. Great mic for presenters because even if they turn their heads to do a powerpoint, they are still right on mic. I try to keep the receiver close, but I still get some hash sometimes.
The Q&A is the e6 and one of the three lavs I have on the ceiling (depending on who’s talking) I’m mixing in real time to bring up the Q mics and then pulling them back down for the A. Leaving the three ceiling mics on full would sound pretty bad.
Regards,
Ty Ford
Want better production audio?: https://home.comcast.net/~tyreeford/AudioBootcamp.html
Watch Ty play guitar: https://www.youtube.com/watch?v=4RZJ9MptZmU