Give your songs full impact. Sub1 Powered Bass Module combines with virtually any portable PA to deliver low end down to 40 Hz. Sub1 offers powerful bass, an optimized center of gravity, and an easy-to-use system for packing, carrying, and setting up. Stack two Sub1 subwoofers for even more bass or to unleash Cardioid Mode for focused, directional performance that negates rear-firing bass energy, steers the bass out front, and reduces feedback.