Like the motor system, the cone assembly of the KFC-XW1300DVC is proprietary. The cone, a 13" rather than 12", is actually a two-piece type with a non-pressed pulp-type rear cone combined with a PBO cone pressed into what Kenwood calls the "Tornado" shape. PBO, also known as Phenylene Benxobisoxazole (yeah, I can't pronounce it either), looks like aluminum but is a woven fiber that has a tensile strength greater than Kevlar and carbon-fiber. It's extremely stiff and provides a rigid pisto -the goal for every subwoofer. The PBO cone is also a single piece cone so there is no dustcap. Coupling the cone to the motor is an 80mm-diameter (3.14-inch) voice coil wound on an FPR (Fiber Resin Plastic) high temp former that has two separate, two-layer voice coils. Each layer is wound with flat wire, like the edge-wound voice coil mostly used in high SPL pro sound woofers.
Suspension for the KFC-XW1300DVC is provided by a 1.25-inch-wide rubber NBR (a compound of rubber and plastics) surround and two oppositely positioned 8.5-inch-diameter linear conex spiders, one mounted above the voice coils and one mounted behind the voice coils. Lead wires from each voice coil pair were woven into the top spider to prevent noise and connected to a pair of color-coded, gold-plated, five-way binding posts. Just below each binding post set are sockets with 25-amp car fuses. If you blow these, either your car just got caught beneath a falling high voltage power line, or your girlfriend just twisted the volume control up to 10 with her knee while reaching for her purse.
In the LabParameters for the Kenwood KFC-XW1300DVC were measured using the LinearX LMS (with the Windows LMS4 software) analyzer, the new Windows version of LEAP (LEAP 5.0 Enclosure Shop software) and the LinearX VIBox. Tests were comprised of both free-air and added mass (delta mass) impedance sweeps done using the current source (admittance) method. This means the woofer was connected directly to an amplifier (not through a 600-1000-ohm resistor) and the voltage and current measured separately at a series of successively higher voltage levels, with each two-curve pair (voltage and current) divided to produce an impedance curve. Measurements were taken a 0.3V, 1V, 1V with added mass, 3V, 3V with added mass, 5V and 10V. I was not able to use higher voltage sweeps on the XV1300 as in free-air it begins to exhibit non-linear behavior that data cannot be derived from. This data was copy/pasted into the LEAP 5 software and the curve fitting parameter derivation menu used to produce the T/S parameters and computer box simulation data provided in the Data Chart.
T/S parameters depicted in the Data Chart were used to perform computer box simulations. The KFC-XW1300DVC was designed for high SPL performance in small sealed boxes, so I set up LEAP 5 to simulate the woofers operation in a 0.55ft3 and a 1.0ft3 sealed enclosure, each with 50 percent fill material (fiberglass-note that while fiberglass isn't necessary to damp high frequencies in the box, it does minimize the box Qtc for a given box volume).
In the 0.55 cubic foot closed box, the KFC-XW1300DVC produced a low-frequency rolloff of 55.2Hz with a box Qtc of 0.83. The graph curves in Figure 3 show the SPL at 2.83V (blue curves) in half-space, at 2.83V in a small 154-cubic-foot car compartment (black curves), and at the SPL at a power level required to get maximum linear excursion (red curves). The 0.55-cubic-foot sealed box curves are solid lines and the 1-cubic-foot box curves are the dashed curves. Increasing the voltage input to the computer simulation to 56V pushed the woofer excursion to Xmax +15 percent and yielded a respectable 117dB.