You need to make two microphone preamp circuits that match the type of microphone you have.
You need a mixer circuit with a line level output and an output to three power amplifiers.
You need the circuit for three power amplifiers.
The circuits are on the internet and can be found by a search with Google.
thanks alot
i have to test it on proteus samulation
but i have some qestion
1 - i want to use the simple mic like it use with pc
2 - what is frequency and if mixed the tow input from mic it is clearly signal or crash
3 - what value of resister must i have to put in the input and outpu
4 - can u tell me the site give this circuit