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: Rockville RVW1800P4 1800w Raw DJ Subwoofer 4 Ohm Sub Woofer 107OZ Magnet, 18" : Electronics
Amazon.com: Gikfun 2" 4Ohm 3W Full Range Audio Speaker Stereo Woofer Loudspeaker for Arduino (Pack of 2pcs) EK1725 : 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: GRS 3FR-4 Full Range 3" Speaker Driver 4 Ohm : Electronics
Amazon.com: Pair of E-12 V.3 D4 - Sundown Audio 12" 500W RMS Dual 4-Ohm EV.3 Series Subwoofers : Electronics
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: SAVARD Speakers HiQ Series 6.5" inch Dual 4 Ohm Subwoofer : Electronics
Amazon.com: Skar Audio EVL-15 D4 15" 2500 Watt Max Power Dual 4 Ohm Car Subwoofer : Electronics
Amazon.com: Fielect 2Pcs DIY Magnetic Speaker 3W 4 Ohm Full Range Audio Speaker Stereo Woofer Loudspeaker Replacement for Arduino, 52mm Diameter : Electronics
Amazon.com: 6.5 Inch Car Woofer Speaker - 300 Watt High Powered White Injected Polypropylene Cone Car Audio Sound Component Speaker System w/ High-Temperature Kapton Voice Coil, 4 Ohm, 40oz Magnet - Pyramid
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: BOSS Audio Systems CH10DVC 1500 Watt, 10 Inch, Dual 4 Ohm Voice Coil Car Subwoofer : Everything Else
Amazon.com: Gikfun 2" 4Ohm 3W Full Range Audio Speaker Stereo Woofer Loudspeaker for Arduino (Pack of 2pcs) EK1725 : Electronics