2.1 StepArray system exampleStepArray columns use external electronics. They are controlled by the UT26 digital signal processor (DSP) andpowered by the MPA6150 6-channel amplifier. Having external electronics has the following advantages:• Possibility to use a single UT26 processor controling several columns, yielding a large cost reduction(see section 2.3 on the next page).• Possibility to use several amplifiers for a single column in order to increase security: failure of one amplifierwould only affect some of the channels, but the column continues to diffuse messages. For example, whenusing 2 columns and 2 amplifiers, amplifier 1 can be connected to channels 1, 3, 5 of both columns, andamplifier 2 to channels 2, 4, 6 of both columns.• Easier maintenance: all electronics can be easily accessed in the technical room.• Electronics can be placed in a fireproof room, with uninterruptible power supply (UPS).The operating parameters of the UT26 processors are tuned with the SAdrive software through RS232 serialcommunication. UT26 processors feature filtering functions such as the control of directivity, equalization, delay,and high level functions.In addition, the StepArray system features a set of options such as subwoofer output (SUB), active gain control(AGC), and security system supervision (SSS).2.1 StepArray system exampleFigure 5 is an example of a complete StepArray installation.The audio signal is fed into the UT26 processors which then supply DGRC compatible signals to the MPA6150amplifiers. A UT26 can also provide sub-bass output when equipped with the SUB option. The settings are madewith the SAdrive software through an RS232 serial bus.RS232BAN2x UT263x MPA6150Audio inputSA12-SWASA250PSA250P4x SA100PFigure 5: Example of StepArray system10