JL Audio M7-12IB: 12-inch marine subwoofer
The M7-12IB is the 12-inch marine subwoofer in the JL Audio M7 series. It is an infinite baffle design: it works with no dedicated enclosure and only asks for a large volume of air behind it. It handles 600 W RMS continuously into 4 ohms.
Three grilles are offered: Classic Gloss White, Sport Gloss White and Sport Gunmetal Titanium. Both Sport grilles can also be ordered with Transflective RGB LED lighting.
Key features
- 12-inch subwoofer, 4 ohm nominal impedance
- 600 W RMS continuous power
- Suggested amplifier 200 to 600 W RMS
- Sensitivity 86.7 dB (1 W/1 m)
- Linear excursion Xmax 18.5 mm
- 102 mm voice coil
- Injection-moulded polypropylene cone with mica filler
Bass
The woofer is optimised with DMA, the proprietary JL Audio technology that acts on the motor, the suspension and the cone profile to lower distortion, improve transient response and deliver clean, well controlled bass. The volume of air a subwoofer displaces is the direct measure of how loud it can play: the M7-12IB displaces more than twice as much as most 10-inch subwoofers, thanks to oversized parts and a very powerful motor.
Parameters
For system designers: free-air resonance 35.34 Hz, Qts 0.791, Vas 56.35 litres, linear excursion Xmax 18.5 mm, effective piston area 0.052 square metres, DC resistance 3.543 ohms. Stated sensitivity is 86.7 dB with 1 W at 1 metre.
Reference volumes
Manufacturer data for anyone who prefers a box: sealed, 85 litres net with a -3 dB point at 35.52 Hz; ported, 141.6 litres net, tuned to 25 Hz with a -3 dB point at 20.96 Hz. The stated wall thickness is 19 mm.
RGB LED lighting
On the With RGB versions of the Sport grilles the patented Transflective system lights evenly, with no glare and no hot spots. The LEDs run on 10 to 14.4 V DC, draw 648 mA at most at 14.4 V and connect through a four-conductor 20 AWG flying lead.
Installation
Outer diameter is 356 mm and the cutout measures 306 mm; mounting depth is 202 mm. Weight is 11.5 kg. The grille stands 37 mm proud of the panel (38 mm for Sport), the fixing holes lie on a 325 mm circle and the driver displaces 4.19 litres. Grille and trim come off easily, which also helps when painting them. Terminals are fork type. Like the rest of the series, this model is made to live at sea and to cope with salt water in the long run.
What's in the box
- One subwoofer
- One grille
- Six stainless fixing screws
- Six stainless washers
