The A108 is two way passive line array system featuring high quality passive crossover network with built-in soft thermal protection circuit boasting an auto-reset feature for LF woofer and HF PDT. Biamp or full-range passive operation mode is user selectable from rear panel. The optional QUBE SP27 is digital signal processing controller programmed to optimize performance of total system and is recommended when using multiple QA108 line array cabinets. Other options include the SP22D, which is a plug in module Digital Signal Processor that is designed for use with the recommended QUBE PA360 power amplifiers, to optimize the sonic performance of a QA108 line array system. Designed for use as main left/right array systems in small to mid-size applications that demand exact throw and even coverage, QA108 line array systems open up new possibilities in creating extreme curvature arrays. That means they can be used as down-fills, front-fills, side-fills or as compact stand-alone units as well as ground-stacked on top of subwoofers.