12:18 Michael - nooooooo ! “Dynamic mic’s are better quality than condenser mic’s” - is a statement that’s so horribly wrong in so many ways that I’m puzzled where to start.
Different designs of mic’s serve different purposes, so you cannot ever say that generally a dynamic mic is better or worse that a condenser mic UNLESS you specify the use case, and even then there are exceptions to every rule.
What I think Michael might be referring to is a cardiod dynamic mic’s tendency to what is called ‘proximity effect’ where some bass frequencies will be accentuated, sometimes in a way the human ear hears as desirable. This is the root of your ‘eating the mic’ line, but to say this makes dynamic mic’s “better” is plain wrong.
For the use case described another type of mic is perhaps worth considering - this is called a boundary mic because it is typically placed on a flat surface and picks up sound from all around it. Think of a hemisphere with the mic at the centre.
By contrast an omnidirectional condenser mic is going to pick up a spherical pattern around it, while your typical dynamic mic will have a cardioid (as in 'cardiac or roughly heart shaped) pick up pattern and tend to reject sounds that aren’t directed directly into it. This is very useful for podcasts because with several people, each with their own mic pointing at their face, each mic mostly picks up speech from the person it’s pointing at, but not the other people. Oversimplification but close enough.
So you probably want a dynamic cardioid mic for the teacher or child presenting - it will pick up their voice, but not the classroom noise. Actually it’s not true that it doesn’t pick up ANY other noise, just that it’s more sensitive to the louder, higher amplitude sounds, right in front of it. You might then consider two boundary mic’s one for each group of students.
They are often used in board room meeting type situations: and so long as everyone is roughly the same distance from the mic they will perform well against a reasonably quiet background level of noise. For example if two students are having a conversation it will pick up both voices, but it can also pick up the the kid tapping their pen on the desk because theyre bored. At some point however simply put across, the students have to get some education about what any mic can and can’t do - for example encouraging softly spoken children to speak up and louder students to be quieter.
Because they have this hemispherical pattern they can go in the centre of a table or on the ceiling above depending on the height of the ceiling and whatever noise sources might be coming through the ceiling. For example, if there’s a classroom on the floor above with students running around or aircon ducting noises etc, then the mic will pick those up - though much less so than an identically placed omni condenser mic. That’s why they’re called boundary mic’s after all.
As with all mic’s they range in price from cheap rubbish through decent value to prosumer and professional grade gear. I don’t know the age of the students but there might even be an argument for using a more low budget option if they’re going to be chucking paint and soda about?
Lastly you should be able to set up something like Carla to handle plugins to deal with noise gates/limiters to deal with some of the room noise without thinking you have to spend more money on hardware compressor/limiter/noise gates. That’s a rabbit hole you don’t want to go down - not for this use case anyway.