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: BOSS Audio Systems CH10DVC 1500 Watt, 10 Inch, Dual 4 Ohm Voice Coil Car Subwoofer : Everything Else
CocinaCo 40mm 4Ohm 5W Full Range Audio Speaker Bass Loudspeaker: Amazon.com: Tools & Home Improvement
Amazon.com: Pair of E-12 V.3 D4 - Sundown Audio 12" 500W RMS Dual 4-Ohm EV.3 Series Subwoofers : Electronics
Amazon.com: MakerHawk 2PCS 4 Ohm 3 Watt Speaker for A rduino Single Cavity Mini Speaker Full-Range Cavity Mobile Portable Advertising Machine Speaker with 11mm Line Length JST-PH2.0mm-2 pin Terminal : Electronics
Amazon.com: Gikfun 2" 4Ohm 3W Full Range Audio Speaker Stereo Woofer Loudspeaker for Arduino (Pack of 2pcs) EK1725 : Electronics
Amazon.com: PRV AUDIO 4 Inch Midrange Speaker 4MR60-4, 60 Watts Program Power, 4 Ohm, 30 Watts RMS Power Pro Audio Loudspeaker (Single) : Electronics
Amazon.com: Skar Audio EVL-15 D4 15" 2500 Watt Max Power Dual 4 Ohm Car Subwoofer : 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: 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