The MX650-CCX 6.5-inch coaxial speaker is designed around the standard marine 6.5-inch speaker format and features a wide mounting flange with a six hole mounting pattern. The long excursion woofer design and excellent power handling make your music come through loud and clear at speed, or at anchor. The woofer design is optimized to operate with a large volume of air behind it (at least 2 cu. ft. / 57 l). Operating this coaxial system in less space will compromise its low frequency performance. A 0.75-inch pure silk dome tweeter, specially treated to withstand the marine environment, handles the high-frequency duties. Silk has been chosen for its lightness, excellent damping properties and smooth response