One recent project was for the retrofit of a small Methodist Church in Madison, Alabama. It was being remodeled to become a campus of a larger existing congregation, complete with AV set up for team preaching between pastors at both locations. The original builders had not taken acoustics into consideration, and the sanctuary for the new campus was a very wide rectangle with completely hard surfaces. AEC calculated the existing reverberation time, measured the flutter echo, and recommended sound absorbing treatment to achieve a better environment for amplified music and speech, as you can see here: RT calc chart. The church worship leader was able to source the materials affordably, and partly through donations, so this congregation could enjoy their worship without distracting echoes and muddy speech.