Amazon.com: Gikfun 2" 4Ohm 3W Full Range Audio Speaker Stereo Woofer Loudspeaker for Arduino (Pack of 2pcs) EK1725 : Electronics
Amazon.com: Kicker 43DSC504-RS DS Series 5.25-Inch 70W 4 Ohm Coaxial Car Audio Speakers - Refurbished : 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: 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: Gikfun 2" 4Ohm 3W Full Range Audio Speaker Stereo Woofer Loudspeaker for Arduino (Pack of 2pcs) EK1725 : Electronics
Amazon.com: Rockville RVW1800P4 1800w Raw DJ Subwoofer 4 Ohm Sub Woofer 107OZ Magnet, 18" : Electronics
CocinaCo 40mm 4Ohm 5W Full Range Audio Speaker Bass Loudspeaker: Amazon.com: Tools & Home Improvement
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: 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: SAVARD Speakers HiQ Series 6.5" inch Dual 4 Ohm Subwoofer : 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: Pyle 12" 6400W 4-Ohm DVC Car Stereo Power Audio Subwoofer Set, 4pk | PLPW12D : Electronics