Wiring: Three Wires Must Be Connected 2. Car Underseat Slim Amplifier 600W Subwoofer Audio Amp Sub Bass Box Speaker 8". 600w Bass, the 68mm Thin Subwoofer Is Directly Installed Under the Passenger Seat.
eBay
50W*2 High-power Audio Speaker D42 Fever Desktop Hifi Passive Bookshelf Speaker TV Surround Front Guide Wall-mounted Speaker
Aliexpress UK
KANTO YU4 SPEAKERS. Never have we had speakers that do so much from a compact stylish cabinet ever before! Throw on your latest vinyl with a built-in phono preamp, or sit back and stream your carefully curated playlist via Bluetooth™ 4.0 with Qualcomm aptX.
eBay
New Bathroom Waterproof Wireless LED Bluetooth Speaker Large Suction Cup Mini Portable Speaker Outdoor Sports Stereo Speaker
Aliexpress UK
Multiple inputs and outputs: support Bluetooth / Coaxial / Optical / USB(PC-USB/U-disk) / 2 groups of Stereo RCA inputs, compatible with phone, computer, TV, CD player, MP3, etc., can greatly improve the sound quality for them. U-disk input supports lossless formats such as APE, FLAC, WAV etc., Besides the speaker output, the 6.5mm headphone jack can easily drive 16-300Ω headphones, easy to enjoy HiFi music. High power output: Rated 35W+35W output, easily drives most home passive speakers, and reproduces the details of the sound well. Specially designed with a low-frequency output to connect an active subwoofer to build a 2.1-channel audio system, providing high-quality music for audiophiles.
eBay
2Pcs/lot 2 Inch 4 Ohm 15W-20W Tweeter Speaker Super Audio Speaker Silk Membrane HIFI Mini Loudspeaker DIY Home Theater
Aliexpress UK
Max Output Power: 600w / RMS: 90W. 1 x Active Subwoofer. 1 x Subwoofer High Level Input Line. Bass Boost: 0to+18db. 68 mm Slim fuselage, installed under the seat. Low Level Input Sensitivity: 300mV. High level Input Sensitivity: 0.9v.
eBay
M1 Portable Bluetooth Speaker Music Stereo Surround Mini USB Outdoor Subwoofer Speaker Audio Player Speaker Microphone
Aliexpress UK
The Phoenix Gold ZB8P subwoofer is designed with maximum yield in a space at a competitive price. Phoenix Gold Car Underseat Subwoofer. Subwoofer Boxes. Subwoofer Grilles. Subwoofer Accessories. CD Changer Leads Magazines.
eBay
Portable Speaker Car Mount For JBL Flip 6/Flip 5/Flip 4/ Wingman Golf Speaker Mount Strap Speaker Holder Storage Rack
Aliexpress UK
The OptiSound enclosures are perfect for those looking to add bass to their system but want a stealth install or don’t have the space to spare for a large enclosure. Type enclosure. Characteristics tight bass.
eBay
11 Colors LED Speaker Cover For BMW G20 New 3 Series High Pitched Loudspeaker Speaker Decorative Lights Surround Sound Refit
Aliexpress UK
T178.636 - Power Dynamics PDY212SM Active Stage Monitor 12".
eBay
Boombox 3 High Power, High Volume Wireless Bluetooth Speaker Outdoor Camping Sports Bluetooth Speaker Home KTV Party Speaker
Aliexpress UK
Don’t fret though; I got you. The best place to install a small powered subwoofer would be under the driver’s or passenger’s seat, behind the back seat or in the back seat. This will depend on your type of car.
eBay
DIY Audio Modification,6.5-inch(146/168mm)Maze Speaker Empty Box, Car/Home Full Frequency Speaker Box, Speaker Wooden Housing
Aliexpress UK