Featuring the most bass from one box in the industry, the Seismic Audio Quad 18 revolutionizes low end at an affordable price. Four premium 18” subwoofers in a single cabinet become more than the sum of their parts to the benefit of DJs, musicians, and audio enthusiasts everywhere. Arrayed in a cone-to-cone configuration, this innovative design effectively doubles the power handling, lowers distortion and requires only half the air volume per speaker cabinet of traditional designs. The coupled drivers act as one single unit with exceptional low frequency response. Seismic Audio then doubled down on this design by including a second coupled pair of subwoofers in a single cabinet. The result is the Quad 18 and it must be heard, or felt, to be believed. With your purchase, you will receive one 4x18 inch Subwoofer Cabinet pictured and described.