Got a Brand new PX4 PIXHAWK 4 Holybro, 
ESC is Turnigy MultiStar BLHeli-S Rev16 ESC v3
motors rctimer sl2212 920kv 
3s tattu lipo 10000 mAh

using QGC and went with Hexa x build

On powering with battery, tone is 
beep beep beep ----- beep beep beep ----