How many FIR channels make sense for my system?
FIRmaker can work on any level: FIR processing can be applied to individual transducers in a cabinet, to groups of transducers, to entire cabinets or to groups of cabinets (e.g. pairs).
For many practical applications one FIR-channel per cabinet seems to provide a good compromise between improved sound quality and required processing power. In principle, the optimized performance of the line array is determined by the spatial resolution of the sound sources to which FIR processing is applied.
For example, the performance of an array of 4 cabinets cannot be improved much when driving 2 pairs. However, an array of 16 cabinets can easily be enhanced by FIRmaker when driving those cabinets in pairs as long as the distance between individually controlled sound sources does not become too large for sufficient HF control.
For increased control at high frequencies it might make sense to employ one FIR filter per HF transducer.
More FIR filter channels per cabinet would also be necessary to provide steering and control of the horizontal opening angle of the array.