Amazon.com: Car Vehicle Subwoofer Audio Speaker - 6.5 Non-Pressed Paper Cone, Black Plastic Basket, Dual Voice Coil 4 Ohm Impedance, 600 Watt Power, Foam Surround for Vehicle Stereo Sound System - Pyle PLPW6D : Electronics
Amazon.com: Granvela 20W 3-inch All Frequency Range 4-Ohm Speakers Pair of Flax-Fiber Cone for DIY Multi-Media Speakers | Computer Speakers : Electronics
Amazon.com: Kicker 43DSC504-RS DS Series 5.25-Inch 70W 4 Ohm Coaxial Car Audio Speakers - Refurbished : Electronics
Amazon.com: Pyle 6.5 Inch Mid Bass Woofer Sound Speaker System - Pro Loud Range Audio 300 Watt Peak Power w/ 4 Ohm Impedance and 60-20KHz Frequency Response for Car Component Stereo PLG64 : Electronics
Amazon.com: Gikfun 2" 4Ohm 3W Full Range Audio Speaker Stereo Woofer Loudspeaker for Arduino (Pack of 2pcs) EK1725 : Electronics
Amazon.com: Massive Audio MB8 MB Series. 8 Inch 400 Watts, 4 Ohm Pro Audio Midrange/Midbass Speaker for Cars, Stage and DJ Applications. Sold Individually. : Electronics
Amazon.com: BOSS Audio Systems CXX8 8 Inch Car Subwoofer - 600 Watts Maximum Power, Single 4 Ohm Voice Coil, Easy Mounting, Sold Individually : Electronics
Amazon.com: 5 CORE Car Subwoofer Audio Speaker - 8 inch 4 Ohm, 100 Watt Power,1” Voice Coil and Foam Surround for Vehicle Stereo Sound System 110mm Magnet Loudspeaker Woofer Replacement WF 8110G : Electronics
Amazon.com: SAVARD Speakers HiQ Series 6.5" inch Dual 4 Ohm Subwoofer : Electronics