The IDS312-TIS is a column subwoofer designed to complement the ID84 column speaker system. Measuring 1160 x 380 x 350 mm and weighing 31 kg, this passive sub features three 12-inch neodymium LF drivers in a bass-reflex enclosure. With a frequency response of 40–120 Hz and capable of delivering 138 dB peak SPL at 1 meter, it extends the low-frequency capabilities of the ID84 system down to 40 Hz. The hybrid TIS version combines Speakon connectivity with a cloth-covered grille and achieves an IP2X rating. Constructed from 15 mm Baltic birch plywood, it includes M6 rigging points and can be stacked horizontally or vertically with or without the ID84 main speaker.