Does a budget ip hands-free system exist?

Question

Telephony

Good day! I ran into a problem...
I will describe the situation: There are 4 buildings (2 warehouses, 1 repair zone and an administrative block). It is required to make a public address system. What I put into this name: from adm. block, a person by pressing a button on the device can shout into the microphone and he should be heard in the room that he has chosen.
What is the problem?
Analog systems are not considered due to the fact that new (analogue) communication lines will have to be created.
I started looking towards ip solutions and gasped ... The cost of the loudspeaker is more than 30,000 rubles.
Maybe I'm not looking there?

Answer 1

UniFi AC EDU AP as one of the ready-made solutions.

Answer 2

Your task can be solved by Wireless systems https://habr.com/ru/post/404685/
loudspeaker-receiver-transmitter - an elementary way

Answer 3

maybe not there, I immediately googled the option for 7500 + the price of the "swearing" so there is only an amplifier: dev.benitex.ru/domofony-i-peregovornye-ustroystva/...
Collective farm option: you can take OrangePi Zero 700 rubles sd card 200 rubles and supplement it with the sip client program, an amplifier 600r with a spitting iron 1500 rubles, a total of 3000 rubles for everything.

Answer 4

As an option, there are IP video cameras with a microphone and a speaker or a connector for an external speaker