Alpine SWX-1243D

MSRP: $500
Exactly three years ago (Feb. 2005), CA&E put the first-generation Type-X 12" subwoofer through the wringer. Our evaluators were enamored by this driver's feature set and the sheer amount of technology implemented in its design. The listening test revealed that "Alpine has done an incredible job in creating a wonderful sounding subwoofer." With such accolades and glowing praise, why change a good thing?

Rest assured Alpine did not start from scratch, but instead built on the shoulders of its predecessor. In fact, looking at the second-generation Type-X, it's hard to distinguish any changes at all aside from the obvious difference in color of the two-piece, cast-aluminum frame-now a semi-gloss black. But dive deeper into the technical side of things and the real story unfolds.

Scott Neill, product education and training administrator of Alpine Electronics of America, says one of the primary goals in reinventing the SWX 12 was to improve efficiency. Initiating this meant addressing the issue of weight, starting with the three-layer the cone. Tipping its hat to the original, the new gen SWX uses a parabolic-shaped cone with a carbon-fiber layer out front and a Kevlar-reinforced paper layer at the rear. The big difference, however, is the core material in this sandwich that has changed from an aluminum honeycomb to Rohacell-essentially, a foamed acrylic polymer. This strong material is extremely lightweight, thus lowering the moving mass of the driver, and thereby improving efficiency. Rohacell also benefits the cone by adding more bonding surface area with the other layers (compared to the aluminum honeycomb), improving rigidity. Additional stiffening comes from Alpine's "force transfer assembly," an eight-armed injection-molded polycarbonate and glass fiber structure that supplies attachment and support to the rear of the cone and a collar at its base, which connects to the voice coil former.

The second step in bettering efficiency was to address the motor components. While the new structure still uses a three-magnet stack, most of the metal components have been altered to fit the larger 80mm (2.83"), six-layer dual voice coil (VC). Size is not the only thing that changed with the VC. Interestingly, three of the six winding layers reside inside the VC former while the other three wrap around the outside in a traditional manner. Dividing the layers up in this fashion helps maintain cool VC operating temperatures by doubling the wire surface area in contact with the surrounding air. The design also doubles the area in contact with the "Twin-Wall" aluminum former, the latter helping wick heat away. This is particularly important since the VC wire is now made of aluminum (instead of copper as in the previous generation), which is less tolerant of heat than copper. While your first inclination may be to question this decision, it actually benefits the driver by lowering the mass of the moving parts. These design elements also allow the driver to maintain its impressive power handling numbers listed as 1,000 watts RMS and 3,000 watts peak.