External mic for MacBook Pro

If you are going to external speakers, maybe you’ll have a much easier time with an actual physical mixer like this one.  

I use it to "mix" my official work laptop, my personal PC and my streaming music together before going to my amp and speakers.   This lets me hear both my computers, and stream music no matter if I’m working or doing personal stuff. The same applies to using a mic. :) 

By the way, I have one of those.  It works great but if you want to be an absurd audiophile geek about it you can upgrade it with an ifi power supply.  

I do like the idea of a physical mixer. In my case, the laptop and XLR mic can go to two input channels.
I need to output to four Bose S1 Pro units. Would I need some type of wireless (mic + 4 receivers) system, or could bluetooth still be feasible?

Thanks again!

Well I am aware that there are mixers with built-in BT outputs, and you can also buy BT transmitters, how well they would integrate with your 4 receivers I have no idea.  Worth talking to a pro shop about how/if this can be done., I still think your easiest path forward starts with a mixer.