The only small downfall to this is it has a tiny pinhole on the edge of the cone. It doen not affect sound!
More Bass In Less Space:
What is unique and amazing about the new Type-E subwoofer is not only the engineering behind the build, it's the new requirements for them to optimally perform. The new Type-E 10” specification requires 0.5 – 0.85 cubic feet air space for superior performance. That’s 34% less air space used in your vehicle!
Features and Specification
Power Range: 100W-250 Watts
RMS Power Handling: 250 Watts
Peak Power Handling: 750 Watts
Mounting Depth: 135 mm (5.3'')
Mounting Diameter: 228 mm (9'')
Displacement: 0.055 cu. ft. (Front Mount)
Added Volume: 0.061 cu. ft. (Reverse Mount, Magnet Out)
Frequency Response: 29Hz-1000Hz
For more info on it visit: http://www.alpine-usa.com/product/view/swe-10s4