The Kenwood KSC-SW11 features an 8.25 x 5.15-inch woofer. The rectangular shape is unique among under-seat car subwoofers, but it allows the subwoofer to fit in a much smaller enclosure. While the performance was above average, the size of the bass isn't great, even for an under-seat subwoofer.
The KSC-SW11 has an MSRP of $249.95, but the market price is around $134, making this one of the most affordable car subwoofer on the market. By comparison, the Pioneer TS-WX1210A has the same market price, but these subwoofers couldn't be more different in terms of size and performance. The Kenwood is exceptionally small and fits under your car's seat while the TS-WX1210A is a beast of a subwoofer, requiring a trunk installation.
In the performance tests, the KSC-SW11 earned a B+ grade. It can sound very good within a mix. You won't have diminished mids and highs as it fills out the low-end. However, when I isolated the bass by disconnecting the speakers, the bass wasn't nearly as tight as it seemed. Perhaps it's the almost rectangular shape of the woofer, but the bass sounds a little more aggressive than other under-seat subwoofers. At high levels, there is noticeable distortion and clipping – something not heard in the Infinity BassLink SM.
The size of the bass earned a C grade, the lowest of the powered car subwoofers in my test. It's not surprising considering both its size and the relatively weak 75-watt amplifier. It's certainly capable of rattling the teeth between your ears if you turn the bass up all the way, but the performance quickly deteriorates and doesn't justify it. Rather, the sweet spot of the sub's performance is only a hair above 50-percent volume. This is disappointing because it sounds great in the sweet spot but isn't nearly as big as other subwoofers. The under-seat installation makes up for much of the size issues because you're closer to the bass frequencies, but there are bigger sounding under-seat subs available.
The controls are disappointing, receiving a C+ grade. It only has three controls: two dials for the volume and crossover frequency and a switch for the phase control. It simply doesn't provide as much control over the tuning as other subwoofers. That said, each of these controls are on the wired remote, providing better access from the driver's seat.
The Kenwood KSC-SW11 is an affordable under-seat subwoofer with good, though not great performance. It doesn't have the power to knock your socks off, but it may not need it since it's small enough to fit under your seat.