i need a list of Public Address Equipment i need for an audience of 50 000people.?

Answer 1

Actually, you need to employ an Event Manager .. (I do not think you stand any chance of doing it yourself ..)

Hints: Most venu's of this size will have PA kit already built in (Stadiums etc) - if you have a 'green field' site then issues such provision of power, weather proofing (wiring runs etc), insurance etc etc will be paramount ..