Large spaces and metal walls give sounds ample opportunity to bounce. This reverberation becomes an even greater problem when you add fancy microphones to the mix. You may have noticed large panels suspended from airport ceilings or projecting out from the walls. These acoustic baffles do more than offer visual appeal. They are composed of reverberation-reducing materials.
Several manufacturers offer acoustic baffles for churches.
Send a diagram or schematic of your sanctuary or gymnasium to the sound engineers at NCPG so that they can determine the exact sound path of your pastor's words. The engineers will then recommend the size, shape, and composition of baffles for your space. The engineers will also suggest where to place the baffles, keeping in mind both the visual appeal of special furnishings or architectural details as well as the need to direct your pastor's sermon to everyone's ears. NCPG sells the Sonex panel manufactured by Illbruck. That solution will work fine for a congregation that is in transition between a gymnasium and formal sanctuary space.