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: 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: BOSS Audio Systems CH10DVC 1500 Watt, 10 Inch, Dual 4 Ohm Voice Coil Car Subwoofer : Everything Else
Amazon.com: Audiopipe 6" Woofer 150W Max 4 Ohm DVC Sold Each : 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: 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: Skar Audio EVL-15 D4 15" 2500 Watt Max Power Dual 4 Ohm Car Subwoofer : Electronics
Amazon.com: Kicker 43DSC504-RS DS Series 5.25-Inch 70W 4 Ohm Coaxial Car Audio Speakers - Refurbished : Electronics