06 June 2011
One of the advantages of being older than dirt is I can remember experiencing certain breakthroughs in technology in the car audio world. I remember when we went from 8-tracks to cassettes, and then to CD’s; I remember when cars didn’t have separate amplifiers, or even coaxial speakers. Adding tweeters and then real power was certainly exciting times. Another breakthrough, I remember, occurred in the early ‘90’s, when the folks at Kicker introduced the then revolutionary Solo-Baric woofers to the market. And then a few years later came the Kicker square woofers. Well, if we fast forward to 2011, you may be delighted to learn that it’s now possible to get both of these innovative technologies in a single woofer, at a very reasonable price. I’m referring to the L3 series of Kicker woofers, and specifically to the $249.95 S12L3 woofer they sent to us for our evaluation.
The L3 woofers are the most modestly priced square woofers in the Kicker lineup, and offer a lot of cool technology for only a little scratch. Why square? If you recall your high school geometry, you’ll remember that a 12” square has a lot more area than a 12” circle. When it comes to woofers, more cone area equals greater output! To put some numbers to it, the S12L3 woofer has about 17% more cone area than an average 12” round woofer. So everything else being equal, it will play louder with the same amount of power. The S12L3 is a 12” dual voice coil subwoofer, with a power rating of 400 watts continuous. The sample we received uses a pair of 4 ohm coils, but there is also a dual 2 ohm version available.
If we examine the woofer from the top down, the first thing you notice is the one piece injection molded “SoloKon” cone, with special bracing behind it to ensure minimum cone flex, and light weight. The square basket is made from stamped steel, and is nicely finished in a charcoal gray colored wrinkle texture powdercoat. Venting around the perimeter of the basket assists in cooling the voice coil assembly, and increases thermal power handling. Connecting the SoloKon polypropylene cone to the basket is a square surround made of Santoprene, with special strategically placed ribs in the corner areas to allow the cone to operate in a linear fashion under high excursion conditions. Of course for maximum reliability, the L3 woofers all use the typical Kicker “belt and suspenders” practice of using both adhesives and stitching to attach the cone to the surround. Driving the moving assembly is a 2” four-layer copper voice coil, wound on a Kapton former. The coils are centered in the magnetic gap of the 5.5” motor assembly by a single Polycotton progressive type spider. The L3 subwoofers also use a vented pole piece to further improve voice coil cooling.
Wire connections are made via four well marked spring loaded push type nickel plated terminals, which are placed equidistantly around the basket.
My listening session with this woofer started in the smallest sealed enclosure Kicker recommends, which is 1.25 cubic feet. In this enclosure the L3 woofer had a lot of impact and excitement as well as very good output, but the bass had a lot of overtones and to me, a few of my favorite tracks didn’t sound as natural as I usually like. Next, I mounted the woofer in a 1.75 cubic foot sealed box, and noted a significant improvement. Bass now sounded a bit deeper and more natural, but still had a bit too much ringing for my personal taste. I should note here that others who heard it thought it sounded fine, so maybe I’m just getting picky in my old age. A 3.0 cubic foot sealed encloser was next, and wow, in this enclosure the sonic character of the woofer was completely transformed. Bass was tight, deep and accurate, with none of the ringing or odd overtones I’d heard previously. However, this box volume is quite a bit larger than many of us can manage, so I also did some experimenting with a 1.75 cubic foot vented enclosure. In this configuration, there was significantly more output, and the bass sounded good. It of course lacked the extension of the large sealed box, but of the four enclosures I tried, I believe this would be the best compromise of sound quality, overall output, and enclosure size.
If you have the room, in my opinion, a large sealed box is the way to go with the L3’s. It’s probably worth noting here, that for the ultimate in sound quality, the owner’s manual recommends a 4.6 cubic foot enclosure!
On The Bench
I let the woofer cool off overnight, and after properly caffeinating myself the next morning I measured the Thiele-Small parameters. The parameters I got differed significantly in a couple of areas from what is published in the woofers manual. However, I’ve seen this many times before, and with normal production tolerances, plus making sure the woofer is properly exercised before measuring it, easily explain the differences. And to be fair, it is stated very clearly in the manual that the specifications are subject to change. For reference purposes, I measured the SPL and frequency response of the S12L3 in both sealed and vented configurations of a 1.75 cubic foot box, and the graphs below tell the tale.
Measured Thiele-Small Parameters
Method= Double Curve - Delta Mass
Domain= Free Air
Revc= 1.800 Ohms (coils in parallel)
Fo= 26.3 Hz
Sd= 0.064 M²
Vas= 4.098 Ft³
Cms= 199.522 uM/N
Mmd= 174.909 g
Mms= 0.0184 Kg
BL= 8.821 T·M
Levc= 0.813.9 mH
SPL= 86.6 dB
EPB = 37.34
Quick Tech Specs
Power Handling 400Watts RMS / 800W “Peak”
Frequency Range 25-500Hz
Sensitivity 86.3dB/SPL @ 1.0W/1M
Nominal Impedance (2) 4 ohm coils
The Kicker S12L3 Solo-Baric subwoofer has all the technology and legendary Kicker engineering to make it a best-selling woofer. It’s flexible enough to be adapted to either sealed or vented applications, and that’s something many other woofers can’t do. And with more cone are than any 12” round woofer, it has excellent output too. In a large sealed enclosure, I could be very happy with the overall sound and performance of this woofer on a daily basis. But for me, a 3 cubic foot chunk of trunk space is more than I can realistically give up, so I would probably look to the more expensive L7 series, which I know from experience will work exceptionally well in a more conventionally sized enclosure.