There are hundreds of companies manufacturing car audio subwoofers these days. Most of them are “off the shelf” products built with specific logos or color schemes. As such, very few of them stand out from the rest. The Memphis Car Audio Mojo series subwoofers are different from these also-rans. They offer features and technologies that enhance performance, providing you with improved bass and greater value for your investment. Let’s take a look at the Mojo MJ1212 car audio subwoofer.
Static Features of the Mojo MJ1212
The Mojo MJ1212 is a 12-inch subwoofer rated to handle 1500 watts of continuous power with a peak power handling of 3000 watts. The driver features a unique voice coil impedance selection feature called FLEX. FLEX allows your installer to choose between 1- and 2-ohm impedances to optimize the net subwoofer impedance, thereby maximizing the performance and power production of your amplifier. In the case of the MJ1212, a jumper block on the opposite side of the spring-loaded terminal block facilitates easy impedance changes.
The MJ1212 is based on a sturdy cast aluminum basket that features a bright orange finish. The orange is a nod to the original Mojo subwoofers from many years ago. The basket had a total of eight spokes between the mounting flange and the spider mounting plateau. It’s open beneath the plateau to optimize heat evacuation. While we are on the topic of keeping things cool, the subwoofer features eight vents in the bottom plate, located directly under the voice coil. These relatively large vents also allow hot air to escape from the voice coil. Memphis is serious about its specifications and goes to great lengths to ensure its drivers can handle the power they are rated for.
In terms of the motor structure, the driver features a wide 300-ounce magnet assembly that helps improve efficiency. The significant mass near the voice coil also helps improve heat transfer, allowing the subwoofer to play louder for longer.
Looking at the front of the Mojo MJ1212, you see a full-size high-gloss carbon fiber dust cap that’s stitched to a high-roll rubber surround. Beneath the cap is a polypropylene cone. At the base of the cone is a massive four-inch voice coil former. The large-diameter voice coil is another key to the driver’s impressive power-handling specifications.
Power handling doesn’t mean much without impressive cone excursion capabilities. The engineers at Memphis designed the MJ1212 with a stunning 1-inch (25.4 millimeters) of linear excursion (Xmax) capability. If you really get things pumping, the cone can move up to 1.75 inches.
Performance Modeling
The key specifications of the MJ1212 include a resonant frequency (Fs) of 33 hertz, an equivalent compliance (Vas) of 0.79 cubic feet and a total Q (Qts) of 0.426. Modeling the provided data in BassBox Pro suggests an ideal sealed enclosure for sound quality of 0.8 cubic feet. This enclosure has an F3 frequency of 63 hertz and a total Q (Qtc) that’s nice and low at 0.554. If you need to cram the driver into a tiny enclosure, you can go down to 0.35 cubic feet net and still have a Qtc of 0.7. The F3 frequency will be 61 hertz in this design. These are impressively small enclosure requirements.
Now, if you really want to party, then a bass-reflex (vented) enclosure is the way to go. Our modeling indicates that the volume requirements remain low, but this presents a challenge in building a vent. Memphis suggests a large enclosure with a net volume of 3.3 cubic feet and a tuning frequency of 29 Hz. A pair of four-inch round vents will just be adequate to keep air velocity under control. The graph below shows the predicted output of both enclosures with 1,500 watts of power. If you have the space, the vented enclosure (yellow trace) is almost 16 dB louder at the same power level than the sealed enclosure (red), specifically at 30 Hz.
Serious Car Audio Subwoofer Solution
Aside from the impressive feature set, the Memphis Car Audio Mojo MJ1212 is a real subwoofer – not a woofer glorified for car audio duty. It will, in the proper enclosure, produce prodigious amounts of low-frequency energy, adding impact to your music like few others.
If you are in the market for a subwoofer that can shake your fillings and blur the rearview mirror, drop by a local authorized Memphis Car Audio retailer and ask to audition the MJ1212. You can learn more about Memphis Car Audio products by visiting their website, following them on Facebook, Instagram and YouTube. If you are looking for a local dealer, visit the locator tool on their website.
