The SUBLINE series consists of 12Sa, 15Sa and 18Sa subwoofer models, built-in birch plywood and aimed to extend low frequency response to a wide range of FBT speaker systems. Created with aim to maximize SPL/SIZE ratio, they have class D amplifiers, switch mode power supply and digital signal processor with presets to match any other FBT speaker. With in/out stereo connectors, it is possible to use only one subwoofer with left and right speakers. Optional wheels, ergonomic integrated carrying handles and plywood cabinets allow an easy transport. Active SUBLine 15mm (5/8") Baltic birch plywood cabinet with scratch- and scuff-resistant paint finish. M20 (20mm) top mount speaker stand socket, two aluminum carrying handles. Provides additional low frequency reinforcement when used along with Verve, EvoMaxX and Jolly speakers.