Every church can't afford to hire a sound engineer HOWEVER every church can afford some training. If you're limited to your Deacon, Trustee or volunteer operating the sound board then the least you can do is pay for some training. Additionally it pays to have a competent professional choose and install your sound setup. This will insure that things are done properly and will prevent your ministry from spending more on fixing problems you could have avoided by trying to do it yourself.
As a sound engineer and a church musician, it can be frustrating to play in churches where the sound is comprised. It's frustrating because I have to stay in my lane. I'm not there to be the sound engineer but rather the musician even though I can clearly articulate most of the problems that are going on in worship. Sound plays an important role in how the music turns out in many houses of worship. When the sound isn't right, the effectiveness of the music is comprised in many instances.
I challenge every musician, choir director etc to try and work with your sound ministry to solve critical problems. I try to communicate with my respective sound ministries on a regular basis to work out the sound settings for every worship service. When you build that relationship things do get better. I also challenge every musician, worship leader, choir director etc to get some training on sound, sound boards, microphones, acoustics etc. The more you know, the more you are able to adjust in critical situations.