With fuel prices rising and the trend to have smaller more efficient “green” cars, these days cargo space is a precious commodity. Enter the shallow mount sub, a new breed of subwoofers typically under 4” in mounting depth. CAE has already run a few reviews on flat woofers (with the new Alpine slim sub to follow soon). In a way, that’s indicative of the market for space saving subwoofers.
Several manufacturers have presented their version of the solution to this problem and Cerwin Vega wasn’t one to be left out. Known for its world-famous Stroker subs, Cerwin Vega has been synonymous with innovative and loud subwoofers. Their entry in this field is their new Stealth SMAX Woofer which is currently available in a 12” version with dual 4-ohm, SMAX 124, or a dual 2-ohm, SMAX 122 configuration.
The Cerwin Vega SMAX 122 is a 12” dual 2-ohm shallow mount sub that has a mounting depth of just 3.37 inches. It accomplishes this by mounting its neodymium magnet in front of the cone. The magnet is housed in a plastic cap with the red CV Mobile logo where you would normally see the dust cap. Its mica filled polypropylene cone is joined to a fairly large rubber surround giving it a one way excursion (xmax) of 12.9 mm. Flipping it on the underside, the die cast aluminum frame is finished in a flat black textured powdercoat. Two sets of binding posts as well as the chrome plated vent cover really give this woofer a nice touch. The dual 3” voice coils gives the SMAX 122 power rating of 400 watts. Overall I was quite pleased with the fit and finish of this woofer.
After breaking in the sub for a few hours at 20Hz, I allowed the voice coils to cool before taking my measurements. I hooked it up to my LMS and ran an impedance curve while the sub was in free air. I proceeded to build a sealed enclosure as stated in the manual. I constructed a .75 ft3 enclosure out of ¾” mdf and cut an 11” hole. I liked the fact that the sub had a gasket already attached to the underside of the basket giving it an airtight seal. Small details like that are always appreciated. I then ran another impedance curve in this enclosure. The delta compliance method in LMS was used to achieve the measured Thiele/Small parameters which were very similar to the published specs.
Revc= 3.900 Ohm (coils wired in series)
Fo= 33.890 Hz
Vas= 49.359 Ltr
BL= 16.660 T·M
SPLo= 88.359 dB
I wired the voice coils in series giving me a 4-ohm configuration. I then proceeded to mount the woofer in the .75 ft3 test enclosure. Even though this is a shallow mount sub, you also have to consider the magnet which will protrude almost 2 inches from the baffle. I took a free-field frequency response of the sub in the enclosure and revealed a -3db at around 50Hz. After installing it in the test vehicle you can see that the transfer function of the vehicle flattened the response considerably.
The test vehicle consisted of JL Audio 500/1v2 and 300/4 v2 amplifiers, JL Audio 13TW5 sub, Dynaudio System 362 components and a Pioneer DEX-P99RS head unit. I connected the SMAX 122 to the JL 500/1v2 and initially set the crossover on the Pioneer DEX-P99RS to 90Hz @ 12 dB/oct.
I threw in Dave Grusin’s "Migration" and did a little level setting. It didn’t have quite the same output as my reference sub, as you might expect. After all, considering that my reference sub is a bit larger, no one should be surprised. After a few adjustments were made I was quite pleased with the way the SMAX 122 performed. The output was smooth and the woofer had very good low-end extension. It mated very well with the Dynaudio 8” mid-bass drivers, making for an overall great bass sound.
I played some Sheffield drum tracks which were reproduced accurately with an impressive amount of precision with no signs of fatigue. I then threw in 50 Cent and went to town. The SMAX 122 had no problems playing the heavy bass notes loud and proud. It was able to play everything I had to dish out. Overall I was impressed with the performance of this subwoofer. Given that it came in a small package, the SMAX 122 has some big woofer performance. If you can’t afford the space for a full-size woofer and are looking for a shallow mount sub that will still provide solid bass, you should consider the Cerwin Vega SMAX series.