Description
JL Audio E-Sub : 12-inch (300 mm) Powered Subwoofer
Summary
- 12-inch (300 mm) Powered Subwoofer
- Black Gloss Finish
- White Gloss Finish
- Black Ash Finish
Overview
E-Sub
The E-Sub subwoofer driver features a radical, deep architecture designed to create a highly linear, mechanical action and a motor design with enough linear excursion to handle the most challenging program material.
A totally new switching amplifier was engineered for the E-Subs, with a compact and efficient switching power supply. This design allows us to keep the E-Sub’s dimensions compact while delivering ample clean power that will fully exercise the drivers’ excursion ranges.
The E-Sub’s feature set has been designed to allow the use of E-Subs in a wide range of applications, from full home theater systems to dedicated two-channel music systems, to desktop audio workstations. A true, two-way onboard crossover with high-pass line outputs allows the E-Sub to integrate seamlessly with two-channel systems, and high-level inputs even make it possible to add an E-Sub to systems lacking line outputs. Polarity and variable phase controls make it possible to precisely blend the E-Sub’s output with that of your main speakers.
Every E-Sub is precision-built in JL Audio’s U.S. factory and individually performance-verified and tested to deliver years of listening enjoyment in your home audio or home theater system.
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Dynamic Motor Analysis – DMA Optimized MotorSummary: Detailed Information: DMA is a Finite Element Analysis (FEA)-based system, meaning that it takes a large, complex problem, breaks it down into small solution elements for analysis and then assembles the data to form an accurate, “big-picture” solution. DMA’s breakthrough is that it actually considers the effects of power through the coil as well as coil/cone position within the framework of a time-domain analysis. This gives us a highly accurate model of a speaker’s actual behavior under real power, something that the traditional Thiele-Small models or other low power measurements cannot do. Because DMA does not rely on a steady-state model, it is able to consider shifts in the circuit elements being analyzed. These modeling routines are intense, requiring hours to run for a whole speaker. DMA is able to analyze the real effects of fluctuating power and excursion upon the magnetic circuit of the motor, specifically the dynamic variations of the “fixed” magnetic field. This delivers intensely valuable information compared to traditional modeling, which assumes that the “fixed” field produced in the air gap by the magnet and the motor plates is unchanging. DMA not only shows that this “fixed” field changes in reaction to the magnetic field created by current flowing through the voice coil, but it helps our engineers arrive at motor solutions that minimize this instability. Analyzing this behavior is critical to understanding the distortion mechanisms of a speaker motor and sheds light on the aspects of motor design that determine truly linear behavior:
Our ability to fully analyze these aspects of motor behavior allows our transducer engineers to make critical adjustments to motor designs that result in extremely linear, highly stable dynamic loudspeaker motor systems. The payoff is reduced distortion, improved transient performance and stellar sound quality. |
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Vented Reinforcement Collar (U.S. Patent #5,734,734)Summary: Detailed Information: By reinforcing the critical junction betweeen the cone, voice coil and spider, the VRC greatly reduces failures due to glue breakdown or material weakness. It does this by greatly increasing adhesive contact area and providing stress relief to the spider material at excursion extremes. 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. |
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Floating Cone Attach Method – FCAM™ (U.S. Patent #6,501,844)Summary: Detailed Information: |
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Engineered Lead-Wire System (U.S. Patent #7,356,157)Summary: Detailed Information: 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. |
Specifications
Enclosure Type | Sealed |
Frequency Response (Anechoic) | 22 – 118 Hz (±1.5dB) -3 dB at 21 Hz / 120 Hz -10 dB at 17 Hz / 153 Hz |
Effective Piston Area (Sd) | 84.4 sq in / 0.0545 sq m |
Effective Displacement | 235 cu in / 3.9 L |
Amplifier Power | 1500 W RMS short-term |
Width (W) | 15.5 in in / 394 mm |
Height (H) | 16.23 in / 412 mm |
Depth (D) | 18.39 in / 467 mm |
Net Weight | 73.5 lb / 33.3 kg |