Answer
QSC ALP design employs a combination of FIR, IIR and all-pass filters to address a number of phase-related shortcomings found in many loudspeakers. Used across a range of QSC loudspeakers, ALP design provides consistent phase response allowing easy combination and coherent deployment of loudspeakers within the same sound system. It eliminates typical phase issues occurring when crossing over from subwoofer to top box as well as comb filtering problems when mixing top boxes that do not share the same phase response.