The JBL MTC-300BB12 Three-Cubic-Foot Backbox features extra-thick 16-gauge metal construction and a thick resonance-eliminating lining that also provides extra bass response. Made for the Control 300 Series 12″ Drivers, this backbox has a dual-mounting system for baffle and knockouts on all four sides.

Product Specifications:

External Volume: 3 cu ft, nominal

Internal Volume: 2.4 cu ft.

Knockouts: 22.1 mm (0.87 in) diameter openingFive (5) locations

Height: 308 mm (12.1 in) above ceiling324 mm (12.6 in) total height

Width: 587 mm (23.1 in)

Depth: 461 mm (18.2 in) cabinet505 mm (19.9 in) including side tabs

Ceiling Cutout Size: 378 x 378 mm (14.9 x 14.9 in)

Weight: 23.1 kg (51 lbs)