With subwoofers, size matters. If you want big bass in your system, and you've got plenty of room in your vehicle, it's a good idea to start with a large sub. But subcompact cars and trucks present a dilemma when you want to build a system with great bass. With these vehicles space for bass is at a premium.

I've experienced this first hand as the owner of a small pickup truck - I've only got room behind the seat for an 8" sub in a truck box. For my listening tastes that's fine. But if you're looking for more bump in your ride, you may be looking for more. But since I added the sub into my system a whole new range of special, shallow subwoofers have come onto the market. The slim profiles of these subs, and the small enclosures they fit into, have opened up a variety of subwoofer options for vehicles with limited space.

These new slim subwoofers sport some innovative technologies. JL Audio's Thin-Line subs use a Concentric Cone Suspension system that places the spider outside of the magnet.

In contrast, Pioneer's Air Suspension Control System -- used in the Pioneer Premier 12" sub (right) -- support the woofer cone on a thin cushion of air. This results in subs that are much shallower than conventional subwoofers.

And these subs, along with other shallow-mount models, are optimized to work in small sealed boxes, saving even more space when you're mounting in tight location.  

The benefit is clear. If I wanted to upgrade from my 8" subwoofer, I could put a couple of these Bass Slammer S120S enclosures with a pair of shallow 12" subs in the space I have available. That's more bass than I need, but it may be just right for you!