So take a good look at your boot and make the 1 decision that your addition of a sub revolves around. how much space are you giving up for the enclosure?. Then choose from the 6 options i have produced that cover all aspects.
eBay
8In 12V 600W Car Sub-woofer Car Audio Modified Speaker Portable Car Sub-woofer Active Subwoofer Bass Speaker Car Woofer
Aliexpress UK
The correct enclosure for your woofers is crucial for good bass in your car. From a single 6" to 18" and anything in-between, we have the right combination of quality style and performance. Bottom Depth: 38cm.
eBay
Sennuopu T6 6x9 Car Speakers Automotive Audio Underseat Subwoofer Auto Carro Active Amplifier Sub Woofe Under the Seat for Car
Aliexpress UK
Constructed with High Quality MDF Hardwood. 15mm MDF Face. New Sealed Enclosure. The sizes are approximates and could change without notification. Product Images are for illustrative purposes and could change without notification.
eBay
Audio Car Loaded Enclosures Underseat 12inch woofer speaker enclosure Professional Build 300W
Aliexpress UK
GZIB 2.30BR. IRIDIUM subwoofers with EFP front bass channel and angled rear wall. 2x 30 cm / 12?. Wooden enclosure. Power Handling (RMS)700 Watts. Warranty: 12 MONTHS. Subwoofer GZIW 30. Condition & Warranty.
eBay
2Pcs Black Car Speaker Grill Mesh Enclosure Net Protective Cover for Car Audio Subwoofer 2/3/4/5/6.5/8inch
Aliexpress UK
(Amplifier is built-in and cables are included). Woofer size 30 cm. Woofer material IMPP Composite Seamless Cone. The TS-WX300A features a strong and lightweight IMP (Injection-Moulded Polypropylene) Composite speaker cone that provides solid and rhythmical bass.
eBay
5inch Car Active Bluetooth Subwoofer Portable Speaker 12V 24V 110V 220V Motorcycle Auto Truck Home Speakers Sub Bass
Aliexpress UK
Alpine - SWT12S4 1000 Watts Bass Reflex Tube. Pod Speakers. Alpine - SWT12S4 Specifications Stitched Alpine Logo. 12” (30cm) High-Performance Subwoofer. Heavy Duty Subwoofer Grill. Subwoofer Boxes. Subwoofer Grilles.
eBay
BOMGE 9-Band Car Graphic Equalizer EQ W/Front, Rear + Sub Output, 8V RMS Line Driver, Adjustable Audio Output for Car, Boat
Aliexpress UK
Constructed with High Quality MDF Hardwood. 15mm MDF Face. New Sealed Enclosure. The sizes are approximates and could change without notification. Product Images are for illustrative purposes and could change without notification.
eBay
Car Underseat Slim Amplifier Subwoofer Speaker Audio Sub Bass Box 8 in 600W Auditory Feast for cars, vans, jeeps, SUVs
Aliexpress UK
Woofer Series: Punch P3S (P3SD2-10). Nothing fits behind your truck seat?. Rockford Fosgate has the solution to your problem with the Punch P3S-1X10 shallow 10” loaded enclosure. Wired exclusively with Rockford Fosgate speaker cable.
eBay
1 Set 6/6.5 Inch 165mm Car Audio Wooden Box Modified Subwoofer 150W Paper Cone Blue Foam Edge Speaker Passive Enclosure
Aliexpress UK