MartinLogan Dynamo 700 10-inch Wireless Ready Subwoofer (Single, Black) (Discontinued by Manufacturer) Built-in wireless receiver offers extreme placement flexibility when used with the SWT-1 subwoofer wireless transmitter (sold separately) High-resolution low-distortion 10-Inch woofer pairs a high-power magnet structure with a 10-inch diaphragm to deliver huge excursion Front-firing or down-firing configuration easily converts without need of tools to maximize performance when installed inside of a cabinet The Dynamo 700 comes with custom ETC spikes which can be used in place of the feet to enhance stability on thick carpets