Secondary network hubs are typically mounted to the deck or another approved structure within the ceiling. A loudspeaker is suspended from each one. Up to two of these hubs can be connected to each primary hub offering zones that are 1 to 3 loudspeakers in size. Each secondary network hub replicates the settings of the primary hub to which it is connected. Each zone offers 100 volume steps in 0.5dBA increments and 1/3-octave frequency control.