Soundcheck is one of the most important parts of the audio mix. If you skip or spend a little time on it, it can ruin the entire event. When doing a sound check, you must spend enough time to set the mixer's input gains and fader adjustments. You must make sure all instruments and PA equipment are properly wired and they are working. During the sound check, take the time to tune up the PA system by following all the necessary steps. Check for feedback and other noise issues.
Check all microphones, speaker and subwoofer connections, monitors, and other equipment. Make sure they are working. If any issue is found, take the necessary actions to correct it.