JL AUDIO 12TW1-4 - 30cm Subwoofer

12TW1-4
TW1 12-inch Subwoofer Driver (300 W, 4 ohms)

• Built on JL Audio's patented thin-line subwoofer technology, the 12TW1 delivers a powerful combination of shallow mounting depth and excursion capability, while operating in insanely small enclosures (0.65 cu.ft. / 18.4 liters). This, combined with a special cast alloy frame design, makes the 12TW1 capable of operating in extremely tight spaces. These include under-seat installations in trucks, 2-seat sports cars and many other creative applications requiring a compact, low profile subwoofer design.
• JL Audio's patented thin-line woofer technology compresses the architecture of the 12TW1 using a "concentric tube" structure built into the injection-molded cone body. This structure supports the voice coil and a full annular spider, while permitting the placement of a large motor structure further forward in the speaker than with conventional designs.
• The 12TW1 also features a clever frame design that minimizes the frontal clearance required for the excursion of the driver. This is accomplished by recessing the suspension attachment surface, so that most of the forward excursion occurs within the frame's dimensions. Thanks to this feature, the 12TW1 requires only 0.87 inches (22 mm) of frontal clearance, even with its grille installed. This allows for more efficient use of space and increased enclosure volume within a given overall depth.
• Even though the 12TW1 is optimized for an enclosure much smaller than any other JL Audio twelve-inch subwoofer driver, it never sounds like a big woofer struggling in a tiny box...instead, it delivers all the rich, deep, controlled bass you have come to expect from a JL Audio subwoofer system.
• Very shallow mounting depth (4.62 in / 117 mm)
• No pole vent: permits mounting close to rear wall of enclosure
• Extremely small sealed enclosure volume requirements
• Long linear excursion capability (0.40 in / 10 mm, one-way)
• DMA-optimized motor design
• Patented "concentric tube" architecture
• Patented "floating cone attach method" technology
• Cast alloy frame with flat edges for tight driver grouping
• Injection molded, mica-filled polypropylene cone
• Rubber surround
• Steel mesh grille included with each driver
• Precision-built in USA at JL Audio’s Miramar, Florida factory with global components

General Specifications

• Continuous Power Handling (RMS): 300 W
• Recommended Amplifier Power (RMS): 75 - 300 W
• Nominal Impedance (Znom): 4 ohms

Physical Specifications (Pict.4)

• Nominal Diameter: 12.0 in / 300 mm
• Overall Diameter (A): 12.375 in / 314 mm
• Mounting Hole Diameter (B): 11.0625 in / 281 mm
• Bolt Hole Circle Diameter (C): 11.7 in / 297 mm
• Motor Outer Diameter (D): 5.71 in / 145 mm
• Mounting Depth (E): 4.62 in / 117 mm
• Front Grille Protrusion (F): 0.87 in / 22 mm
• Driver Displacement: 0.072 cu ft / 2.04 L
• Net Weight: 16.5 lb / 7.5 kg

Parameters

• Free Air Resonance (Fs): 32.35 Hz
• Electrical “Q” (Qes): 0.555
• Mechanical “Q” (Qms): 11.066
• Total Speaker “Q” (Qts): 0.529
• Equivalent Compliance (Vas): 1.189 cu ft / 33.67 L
• One-Way Linear Excursion (Xmax)*: 0.40 in / 10.0 mm
• Efficiency (1 W / 1 m)**: 85.15 dB SPL
• Effective Piston Area (Sd): 67.608 sq in / 0.0436 sq m
• DC Resistance (Re): 3.514 ohms

* Xmax specifications are derived via one-way voice coil overhang method with no correction factors applied.
** Efficiency (1 W / 1 m) is not an accurate indicator of a subwoofer’s output capability and should not be used as a comparison to other subwoofers to determine which one is “louder”.

Sealed Enclosure Specifications (Pict.5)

• Wall Thickness: 0.75 in / 19 mm
• Front Baffle Thickness: 0.75 in / 19 mm
• Volume (net int.): 0.65 cu ft / 18.41 L
• External Width (W): 26.50 in / 673 mm
• External Height (H): 14 in / 356 mm
• External Depth (D): 5.50 in / 140 mm
• F3: 45.44 Hz
• Fc: 54.41 Hz
• Qtc: 0.89

Ported Enclosure Specifications  (Pict.6)

• Wall Thickness: 0.75 in / 19 mm
• Front Baffle Thickness: 0.75 in / 19 mm
• Volume (net int.): 1.125 cu ft / 31.86 L
• External Width (W): 31.75 in / 806 mm
• External Height (H): 16 in / 406 mm
• External Depth (D): 7 in / 178 mm
• Internal Slot Port Width (SW): 5.50 in / 140 mm
• Internal Slot Port Height (SH): 2.25 in / 57 mm
• Internal Slot Port Length (SL): 22.625 in / 575 mm
• Port Extension Length (EL): 20.75 in / 527 mm
• Tuning Frequency (Fb): 34.0 Hz
• F3: 31.79 Hz

Enclosure Notes
* The enclosure recommendations listed above are external dimensions which assume the use of 0.75 in (19 mm) thick material. If you are using 0.625 in (16 mm) thick material, subtract 0.25 in (6.5 mm) from each dimension. Do not use any material with a thickness of less than 0.625 in (16 mm) as this may compromise the rigidity of the enclosure.
* All enclosure volumes listed above are net internal volumes! Driver displacement, port displacement and brace displacement must be added to obtain the final gross internal volume. All enclosure dimensions above have already taken this into account.
* When using multiple subwoofers in a common enclosure you will need to recalculate the enclosure and port dimensions. For assistance please contact your authorized JL Audio dealer or JL Audio Technical Support.
* We recommend the use of this speaker in a bi-amplified system using high-quality satellite speakers and a high-quality amplifier. We do not recommend the use of this subwoofer with a passive crossover (coil), as this type of device will adversely affect performance.
* All specifications are subject to change without notice.

Safety Notice
Prolonged exposure to sound pressure levels in excess of 100dB can cause permanent hearing loss. This high-performance speaker can exceed this level. Please exercise restraint in its operation in order to preserve your ability to enjoy its fidelity.

When installing a subwoofer in your vehicle, it is extremely important to secure the enclosure firmly. We recommend bolting the enclosure through the metal of the floorpan or the frame of the vehicle with large diameter washers for reinforcement. If an enclosure is not firmly attached, it can become a projectile in a collision. This is particularly important in a hatchback, station wagon, sports utility vehicle, or van.