With appropriate system setup, the addition of a subwoofer allows your smaller main speakers to be free of the burden of reproducing low frequencies. This allows your whole system to play louder and to sound cleaner at all listening levels. Purpose-engineered and built for real marine duty, the M-Series infinite-baffle woofers are designed to operate without a dedicated enclosure. Long excursion capability and rugged suspension systems help produce deep, powerful bass response that will transform your boat's audio system