This can be a line level system or 70 volt system. With a good quality full ear cup head-set, you have the best signal to noise ratio. Drawbacks on the system are obvious, you must sit at only one location. Therefore, you have to provide many seats with input boxes which drives the cost up. Churches with concrete floors or closed basement ceilings can not use this option.
Installation is labor intensive.
Cost of the system varies. At 12 seats, a wireless system becomes more attractive. A popular system in the 60s and early 70s, the loop system almost disappeared in churches. In recent years, loop systems have been very effect in simultaneous translation systems, school classrooms and business meetings. The design of the system begins with an amplifier, a coil of wire around the area people are seated and various types of receivers.