In rooms where the lectern isn't close to the audience. To back up an installed sound system in case the equipment or power source fails. For traveling ministers, lecturers, and missionaries. These units are very transportable and can operate on batteries. For churches that can't afford a professionally installed system.
Portable systems can provide backup when the usual sound operator is unavailable.
They can also be used with music inputs and recorders, or as a monitor for installed systems. We'd like to start a handbell choir. Bells are grouped in octaves, with 13 bells in the first octave and 12 in other octaves, says Kermit Junkert of Schulmerich Carillons. Most handbell music is written for three to four octaves. You can have up to seven, but that's unusual.