Some basics of mixing sound for live worship
The job of any worship leader (or perhaps church leader using a backing track) along with the guy running the sound is to work together to provide a solid, non distracting platform to aid their congregation in worshipping God. There are many mistakes that can be made from the mixing desk that can hinder (or even destroy) this.
A question to ponder: when setting sound levels in church, who should we treat as the 'lead vocalist'? My suggestion to this is NOT the worship leader nor in fact anyone else singing or leading from the front but it should be the congregation. The roll of the person at the front is to serve the congregation and to focus on enabling them to feel comfortable and sing their hearts out. For the sound guy, it's crucial to make sure the sound of the congregation singing as a unit together is blended in correctly with the sound of any singers, musicians (or backing track) coming from the front. Obviously you can't turn the congregation up or down so you need to make sure that the sum of everything else happening isn't too loud or too quiet in comparison.
You might occasionally experience a church service or large festival event where the music is so loud that you can't really hear yourself singing. Of course, there is a place for that and some love their music to be loud and will feel perfectly comfortable worshiping in that context. However, for the majority of people in a typical local church setting, they will engage more naturally when they can hear themselves singing and blending in with their fellow congregation members. This encourages everyone to feel involved as part of their community worshiping God together and to express themselves effectively.
If you are in a church where you use backing tracks or lyric videos, a really common mistake is to set the track audio too quiet. It's human nature that when we're mixing, we will often naturally (and perhaps even unconsciously) prioritise something that we can see. This means it's quite common to hear a backing track, which is invisible, turned right down with any live vocals or instruments much too loud in comparison. This has the effect of sucking the energy out of the room and can make the congregation feel uncomfortable with the result that the singing becomes weaker. It also increases the chance of the musician(s) and/or congregation drifting out of time with the music. It's really important when using backing tracks that the blend is exactly the same as it would be if there was a live band with any extra live instruments or vocals sitting in the mix correctly.
Once the sound of any musicians or tracks and vocalists is nicely balanced, the most important factor is to keep the sound of the congregation singing at the forefront. If the sound coming from the front is too quiet, they will feel insecure and begin to sing more quietly. If it's too loud, they will become distracted and will disengage. The aim should be to reach a place where the congregation are as comfortable as possible and when they are, the chances are they will be singing their hearts out to God!
Please do let us know any experiences you have of mixing sound in your church which may be helpful to others.