Add a JL Audio powered sub to your car if you’re short on space but still want immersive sound. These compact subwoofer enclosures contain both a woofer driver and an amp that can be installed under the seat. OnlineCarStereo.com has both ported and sealed JL Audio amplified subwoofers in various wattages. There are also dual active subwoofers for maximum slam. We’ll help you find the right bass speakers for your car and can also set up certified professional installation at a brick-and-mortar store.