How would you like big bass without a big subwoofer? Pioneer has developed an excellent solution for those who want power bass with a lot smaller place for the setup. The Shallow Series subwoofers by Pioneer are designed for audiophiles who do not have trucks, SUVs, or any vehicles with space large enough for a conventional setup.
The Pioneer Premier TS-SW1241D is a 12" shallow mount subwoofer that could be mounted virtually anywhere and virtually in any vehicle. Just because it's small doesn't mean that it will not perform as well as conventional-size subwoofer. In fact, user reviews have indicated how the subwoofer produced surprisingly hard bass:

"My friend just purchased two of these subs in the back of his truck and i have seen not many subs hit harder than his. Enough to have your chest feel it. I would defiantly recommend these, i am for sure getting some for my own."
--Kyle from Irvine, CA 4/23/2008, SonicElectronix.com

Size
The first thing anyone would notice about the TS-SW1241D subwoofer is its incredibly shallow mounting depth. Now remember, this is a 12" subwoofer-- a subwoofer that would typically require more than 5 inches of mounting depth; yet, the Pioneer Premier TS-SW1241D only requires a maximum of only 3" mounting depth. This means that the TS-SW1241D is incredibly versatile with its ability to be mounted virtually anywhere.
Construction
The cone is very, very rigid, capable of sustaining high-performance usage as well withstanding minor accidental abuses. It's made up of interlaced glass and carbon fiber reinforced injection molded polypropylene; where polypropylene synthetic plastic on its own would be mediocre at best with consistency and rigidity, the reinforcement material makes it extremely durable and allows it perform well under extreme stresses.
In addition to the cone material, the TS-SW1241D features a 3-layer interwoven radial surround that has the unique and patented M-shaped construction. It behaves much like an accordion, capable of moving around with better flexibility while maintaining great sound linearity.

Unique Air-Suspension System
There is one more unique feature that we want to cover that sets this subwoofer apart from the rest of the competition. We've already mentioned the obvious size, so we have to tell you about its air suspension system. With every subwoofer, you know that there are mechanical parts that move and react depending on the sound it needs to make. If there is too much movement and dis-alignments, the subwoofer's performance will degrade over time. Pioneer has developed an air chamber within the subwoofer construction that forces the air trapped in between the cone and the drive cone as a spring. This way, the cones will react and respond to demands in harmony, giving it much better performance and consistency while maintaining a tight and high-quality bass production.
There really wasn't anything we didn't like about the shallow-mount 12" TS-SW1241D subwoofer. For its size, it's really surprising how good it performs. It's even capable of 350 watts of continuous RMS power handling with 1400 watts max. It could respond to frequencies ranging from 18 Hz to 1000 Hz and has an above average SPL rated at 88dB (1W/1m). Once again, we'll say that the most impressive part about it is its ability to perform so well while only requiring 0.80 cubic feet of enclosure volume. Even the price is right, set at under $150!