Blown 2000w speakers

Hi, have a friend with same A9 mixer that blew one of his QSC 2000W speakers. Told him to ensure normal trim is somewhere between 10-12 o clock. The volumes are just in the orange lights at worst and never go into the red. The LOW is at 12 o clock, but max 2 o clock. Speak volumes are set to 12 o clock. Unfortunately it was someone else who blew the speaker, so is there anything else on the A9 to check to ensure the levels are not too high into the speakers. Thanks for any help