M3 7.7-inch Marine Coaxial Speakers (70 W, 4 Ω) – Gunmetal Sport Classic Grille
Purpose-engineered and built for real marine duty, M3 coaxial systems deliver excellent performance at a more affordable price than our maximum-performance M6 models.
The oversized 7.7-inch design of the M3-770X results in increased efficiency (more output for a given amount of power). This gives them the ability to play louder and cleaner at high volumes than smaller speakers.
The woofer design is optimized to operate with a large volume of air behind it (at least 2 cu. ft. / 57 l). Operating this coaxial system in less space will compromise its low frequency performance.
A 0.75-inch pure silk dome tweeter, specially treated to withstand the marine environment, handles the high-frequency duties. Silk has been chosen for its lightness, excellent damping properties and smooth response characteristics.
Although M3-770X Coaxial Systems can be used with as little as 20 W per channel, for best audio performance we recommend amplifiers capable of between 75-100 W of continuous power per channel.
Sold as a pair.
|Continuous Power Handling (RMS)||70 W|
|Recommended Amplifier Power (RMS)||20 – 140 W / Ch.|
|System Efficiency||90.5 dB @ 1 W / 1 m|
|System Nominal Impedance||4 Ω|
|System Frequency Response||45 Hz – 25 KHz ± 3 dB|
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.
Since 1997, JL Audio has been at the forefront of Finite Element Analysis-based modeling of loudspeaker motors and suspensions. This research is aimed at decoding what we refer to as the “Loudspeaker Genome”… a project aimed at understanding the true behavior of loudspeakers under power and in motion. A major component of this integrated system is DMA (Dynamic Motor Analysis). Starting with the 15W3 and the W7 Subwoofers in the late 1990’s and early 2000’s, DMA has played an important role in the design of all JL Audio woofers sold today, including our component woofers.
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:
- Linear motor force over the speaker’s operational excursion range
- Consistent motor force with both positive and negative current through the coil
- Consistent motor force at varying applied power levels
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.
Marine Materials / Testing
The design of marine products requires extensive materials testing to achieve reliability and longevity.
Building serious marine products requires a real commitment to environmental testing and materials specification. To this end, JL Audio has invested in Ultraviolet testing chambers (to simulate years of sun exposure) and Salt Fog chambers (to simulate years of exposure to salt-water environments). This testing is critical to building products that will not only sound great in your boat, but will also sound great for many, many years.
- injection-molded mica-filled polypropylene cone bodies with synthetic rubber surrounds, specifically formulated with UV inhibitors for marine duty.
- Marine-grade, synthetic fiber spiders with progressive roll designs to withstand high humidity.
- Specifically engineered polymer baskets are corrosion and UV-resistant and encapsulate the woofer’s motor system to prevent corrosion.
- Gold-plated, marine-grade brass connection terminals
- Marine-grade stainless steel mounting hardware is included.