ESS Factory Replacement Speaker, 10" Woofer, 689-1012 ESS AMT Speaker Woofer Part # 689-1220 Original factory ESS Part Size: 10.625", Cut-out: 9.375", Depth: 4.5", Magnet: 35 oz Impedance: 4 ohms, Re: 3.4 ohms Le: 1.2 mH, Fs: 27 Hz, Vas: 1.75 cu. ft., Qms: 4.1, Qes: .54, Qts: .48, Xmax: 4mm