250W RMS 8" Enclosed Subwoofer System
With MicroSub+™ systems, the power is built right into the subwoofer system. Housing a proprietary Class D amplifier, this incredible subwoofer system utilizes our exclusive DCD™ amplifier technology to extract maximum output from its specially engineered, ultra low-impedance W3v3 driver. By combining direct power conversion with an ultra-high current output section, DCD™ amplifiers are free of conventional switching power supplies, enabling them to generate remarkable power with unprecedented efficiency.
Key to the enclosure’s performance is its efficient slot-ported design and precise tuning of its 8Wv3 Subwoofer. Extensive interior bracing permits the use of thinner wall material that maximizes the enclosure's internal volume relative to its exterior volume. The port wraps around two walls of the enclosure to produce the necessary low tuning frequency that ensures excellent extension and response smoothness. The flared port entry and exit further enhance sound quality by minimizing air-flow noises through the port.
Integration to OEM and aftermarket head units is a snap thanks to a variety of input options and automatic turn-on capability (via signal sensing or DC offset sensing). Also included is a variable frequency low-pass filter (50-200 Hz), along with output polarity control switch. Adding an optional RBC-1 remote level control (sold separately) lets you control subwoofer levels directly from the driver’s seat. A quick-disconnect power connector makes it easy to remove the subwoofer when you need the extra space. As with all MicroSub™ systems, these amplified versions produce the kind of output and extension normally associated with much larger systems.
Note: DCD™ amplified systems use very specific components. Never use a DCD™ amplifier or its companion subwoofer(s) with incompatible, non-DCD™ products. Doing so will void the warranty and may cause severe damage.
Finish: Black, high-grade automotive carpet with silver “JL AUDIO” embroidery on front baffle. A steel mesh grille is included to protect the Subwoofer. Construction: CNC-Cut High-Grade MDF.
DCD™ Amplifier Technology
The most efficient subwoofer amplifier technology on the market delivers impressive power with minimal current draw and heat.
The conventional way to get high power in a car amplifier is to use a switching power supply. This increases the battery voltage from its nominal 12V to something higher–the more powerful the amplifier, the greater the required voltage. This power conversion is never perfectly efficient–about 10% of what goes into the amplifier is wasted and ends up dissipating into heat.
JL Audio's Direct Conversion Class-D Technology (DCD™) innovates by eliminating the need for this power conversion step entirely. Because we are still bound by the laws of physics, the lack of a step-up power supply means we have to extract as much power as possible from the vehicle's 12V supply. If we were to connect a DCD™ amplifier to a conventional 4-ohm subwoofer with this limitation in place, we would only achieve about 25 watts, and we all know that powering a subwoofer requires a lot more power than this.
To overcome this obstacle, the DCD™ amplifiers have been designed to drive extremely low impedance speaker loads–as low as 1/4-ohm (0.25 ohm)! With these very low impedance loads, we can deliver up to 500 watts of clean power, subwoofer power. Those who know Ohm's law and that nothing is free realize that this will require a lot of current to flow, and that's exactly what DCD™ is engineered to deliver...over 50 Amps peak into a speaker!
To deal with these high current amounts, the special, very low-impedance JL Audio Subwoofers used with DCD™ amplifiers are engineered with unique voice coils and tinsel leads. Connections between the amplifier and speaker are made using special heavy gauge speaker cable, with special attention paid to connection integrity to deal with the high current output.
The benefit of all this effort is that DCD™ amplifiers completely avoid the losses associated with a switching power supply, allowing the entire amplifier to achieve total power efficiencies in the 91 - 94% range. This is very close to the theoretical limit for Class-D efficiency and results in very little heat being generated. All of this allows for a very compact, powerful amplifier that can fit in some of our most space-efficient enclosed systems.
V-Groove MDF Construction
We begin with quality medium-density fiberboard, which is then machined on our CNC-controlled KOMO woodworking stations. These powerful machines are able to cut a wide range of features onto a sheet of MDF, with minimal waste and absolute precision. The KOMO machines cut out the woofer holes, terminal holes, cut dado grooves, create countersinks and most importantly, cut the angles at the edges of the panels that form the enclosure's main shell so that these panels fit together precisely, with no gaps or leaks.
Once the panels are cut, assembly technicians line them up in the correct order and glue their outer faces onto a long piece of carpet, creating a "wrap": a long series of panels, hinged temporarily by the carpet. In the next assembly step, our wood assembly teams fill the V-grooves between the panels and any dado grooves that receive dividers or secondary wraps with wood-glue. Once the glue is applied, the enclosure shells folds together along the V-grooves, capturing dividers in the dado grooves and secondary wraps, and evenly spreading the glue throughout the joints. One line of mechanical fasteners is applied to hold the structure together while the wood glue dries.
The V-groove technique greatly improves assembly efficiency, and also results in a far stronger and better sealed enclosure than the typical butt-joint construction found on imported enclosures. The quality of the MDF used in JL Audio systems is also vastly better than the typical “China-Grade MDF” used in the imported products.
The flared slot-port design reduces turbulence at the port mouth so as to minimize any audible airflow effects common to ported enclosures.
While ported enclosures deliver important efficiency advantages over their sealed counterparts, they also present unique design challenges. In car audio, the desire for lower tuning frequencies from small enclosure volumes leads to long port lengths that often require compromising the port area. These compromises lead to higher airflow speeds through the port, which can create noise as the air is driven across the edge of the port. The flared port design minimizes these airflow effects by providing a smooth transition for the high-speed air flow, rather than an abrupt termination. The result is less noise and cleaner-sounding bass.
Dynamic Motor Analysis - DMA Optimized Motor
JL Audio's proprietary Dynamic Motor Analysis system is a powerful suite of FEA-based modeling systems, first developed by JL Audio in 1997 and refined over the years to scientifically address the issue of speaker motor linearity. This leads to vastly reduced distortion and faithfully reproduced transients... or put simply: tight, clean, articulate bass.
Elevated Frame Cooliing
JL Audio's Elevated Frame Cooling design delivers cool air through slots directly above the top-plate to the voice coil of the speaker. This not only enhances power handling, but also sound quality by minimizing dynamic parameter shifts and power compression.
Many speakers employ venting techniques to enhance voice coil cooling. This is typically accomplished by having big holes in the sides of the frame just below the spider attachment shelf. While it provides a modest cooling benefit, this low-velocity air-flow does not blow directly or strongly on the voice coil.
Our design improves upon this cooling technique in a number of ways. By elevating the frame above the top-plate of the motor (via stand-offs integrated into the bottom of the frame) a narrow, high-velocity air-path is created between the bottom surface of the frame and the top surface of the top-plate. This air path leads directly to the voice coil and then turns upward into the spider air cavity. By utilizing the pumping action of the spider through this focused air path, a large volume of cool air hits the coil windings directly.
Another important benefit is that the upper surface of the top-plate (one of the speaker's hottest parts) is directly exposed to cooling air flow, whereas on a conventional design it is isolated from the air flow by the lower flange of the frame. The elevated frame technology greatly increases thermal power handling, reduces compression effects and does so without any additional parts.
FCAM™ Floating Cone Attach Method
This assembly technique, conceived by JL Audio, ensures proper surround geometry in the assembled speaker for better excursion control and dynamic voice coil alignment.
JL Audio's patented FCAM™ technology is an innovative method of bonding the surround/cone assembly to the voice coil former/spider assembly. This feature helps ensure concentricity of the surround, spider and voice coil without torquing the suspension to achieve it. This allows for the inevitable, slight variations in production part dimensions without having them negatively impact the integrity of the suspension and coil-centering at high excursions.
VRC® Vented Reinforcement Collar
JL Audio's Vented Reinforcement Collar (VRC®) improves the rigidity and stability of the cone/spider/voice coil junction and directs airflow over the voice coil windings for improved thermal performance.
The Vented Reinforcement Collar (VRC®) is a composite structure that addresses two issues related to reliability.
The VRC® also features slots that facilitate air flow directly onto the voice coil windings. This reduces thermal compression effects and enhances reliability. Current versions of the VRC® also incorporate lead-wire strain relief structures to improve mechanical reliability.
Insert Molded Sub-Assembly
Spiders, voice coils, terminals and lead wires are preassembled, using a patented process, onto a composite carrier for improved precision and reliability.
A conventional speaker is assembled in layers. In other words, multiple parts are assembled and glued sequentially into the basket, leading to stacking of tolerances and making it difficult to achieve optimal assembly precision.
JL Audio's patent-pending insert-molded spider carrier permanently bonds the spider to a mechanically robust carrier that also incorporates the terminal assembly and lead wire strain relief features for enhanced reliability and optimal alignment of parts. This subassembly is assembled outside the speaker basket, for optimum alignment and glue-joint integrity. The benefit is a more precisely built, more mechanically sound loudspeaker.
Customizable Trim Ring
This removable ring can be painted to match the installation theme and directly receives JL Audio grille mesh inserts (sold separately).
This ABS trim ring is molded in black, but that doesn't mean it has to stay that way. By custom painting it, you can match your installation theme and create a personalized look.
Specifically-designed grille mesh inserts are available separately and fit into the inner diameter of the trim ring. Helpful Tip: Installing the grille mesh inserts is much easier before mounting the woofer into the enclosure.
Engineered Lead-Wire System
Carefully engineered lead-wire design and attachments ensure controlled, quiet lead-wire behavior under the most extreme excursion demands.
Managing the lead-wires on a long-excursion woofer is one of the trickier aspects of its mechanical design. To address this, many long-excursion woofers today rely on a simple solution that weaves the lead-wires into the spider (rear suspension) of the driver.
The biggest problem with this approach is that spider limiting behavior plays a hugely important role a woofer's performance. Lead-wires that are attached or woven into the spider material can alter the spider's "stretching" behavior. The tinsel wire naturally has less 'give' than the fabric material of the spider leading to asymmetrical spider behavior and non-uniform stress distribution around the spider circumference. The wire attachment points can also cause localized pulling and tearing forces at the spider's excursion limits. As such, longevity becomes a major concern and makes the woven-in design less than ideal for very long-excursion designs.
While a traditional 'flying lead' design does not compromise spider linearity or radial stability, it creates its own challenges on a long-excursion woofer. Managing the 'whipping' behavior of the wire and making sure it does not contact the cone or spider is one challenge. Another is ensuring that the leads do not short one another or the frame of the woofer.
To overcome these issues, JL Audio's engineered flying lead-wires work in conjunction with carefully engineered entry and exit support structures molded into the terminals and the voice coil collar. Some models also feature jacketed lead-wires to further reduce the likelihood of shorting and fatigue. The result is flawless high-excursion lead-wire behavior, with outstanding reliability and none of the compromises inherent to a woven-in lead wire system. Building woofers this way requires much more labor and parts complexity than the simpler woven-in approach, but the payoff is in reduced distortion, reduced mechanical noise and improved reliability.
Built-In USA with Global Components
At a time when most audio products are built overseas, JL Audio’s commitment to in-house loudspeaker production continues to grow. To pull this off in a competitive world market, our production engineering team has created one of the world’s most advanced loudspeaker assembly facilities and established a global network of quality component suppliers who build to our specifications. This, combined with our commitment to state-of-the-art assembly technology, allows our skilled workforce to efficiently build JL Audio products to extremely high quality standards, right here in the U.S.A.
|RMS Power||250W RMS|
|Shallow Mount Enclosure||No|