JL Audio - 12 Volt Tuning

The cone for the W6v2 is also similar to the W7 cone. JL Audio uses a two part polypropylene cone: a shallow profile oversized dust cap (this finishes the front of the speaker) with a W-shaped cone (profile) adhered beneath. It is this shape that gives the cone its name, the W-cone. The combination of these two results in a very light and extremely stiff cone assembly. The lower, W-shaped cone also has a trough indentation that gives the voice coil lead out wires a little more room to move.

Providing compliance and cone control is a foam surround that measures 30mm in width by 15mm in height. The remaining compliance is supplied by the nearly 8-inch-diameter, progressive roll, poly cotton-impregnated spider. The distance from the spider mounting shelf to the top plate is a substantial 151/48 inches, which allows plenty of clearance for long rearward excursion.

Attaching the spider and voice coil to the cone is accomplished by yet another proprietary system called Plateau-Reinforced Spider Attachment. This is a variation of the JL Audio VRC attachment collar that increases the stiffness of the neck joint so that the cone does not deform on long excursion strokes. The company claims this allows for better alignment of both parts and is called FCAM, for Floating Cone Attach Method.

Driving the cone assembly is a 2.75-inch-diameter, four-layer (two, two-layer coils) voice coil wound on a high temp Kapton former with round aluminum wire to keep the mass of the cone/voice coil assembly as low as possible. This dual voice coil version with two 4-ohm voice coils is the only version available on this model. The lead wires from the voice coil are also non-conventional in nature. While the entire industry uses tinsel lead wire, JL Audio got innovative and went to a flat insulated four-conductor (two leads for each voice coil connection) co-extruded ribbon wire. The ribbon wire connects to a new type of terminal jumper system. This terminal block has two color-coded push terminals to connect to an amplifier, but also has four output lugs that are the connecting points for each of the two voice coils. Using the two supplied 4.5-inch jumper wires, a user can easily configure the JL Audio 12W6v2 with either both voice coils in parallel or series. Last, the W6v2 series includes a removable trim ring that can be painted to match any installation theme and an optional mesh grille.

In The Lab
This section is divided into two parts, Klippel analysis and LEAP analysis. Using the Klippel analyzer (on loan from Klippel GmbH) Pat Turnmire, CA&E reviewer and CEO of Redrock Acoustics, performed the analysis of the JL Audio 12W6v2-D4 woofer and provided the Bl (X) curve shown in Figure 2 (below). The dark curve is the Bl curve and shows the motor strength of the woofer as it moves in both directions from center. The lighter curve is a sort of displacement curve - if both curves lie on top of each other, the motor system would be perfectly symmetrical. Ideally, the Bl curve would be centered on the 0mm point (where the cone is positioned when there is no signal). When a woofer shows an offset, which is the result you get from most woofers, it means that the magnetic and mechanical systems have not been completely optimized and motor strength will decrease faster in one direction (usually the outward direction) than the other, and this means more distortion at high operating levels than if it were operating perfectly symmetrical and providing equal motor strength in both directions. Looking at the JL Audio 12W6v2-D4 Bl(x) curve, all I can say is that this is about as close to perfection you are going to get this side of Nirvana (the spiritual high plane, not the band). In our conversation regarding the 12W6v2's performance on the Klippel machine, Pat commented that this was hands down the most linear woofer he had examined to date. So what does all of the techno speak mean? It means the JL 12W6v2-D4 should maintain its sonic integrity and have only minimal changes in its subjective sound quality throughout its operating range - and that's a good thing.