JL Audio 12W3v3-4 Subwoofer
Unless you're planning on attending SPL competitions, the JL Audio 12W3v3-4 is one of the best subwoofers for everyday use. The W3v3 series strikes the perfect balance between bass output and sound quality - the 12W3v3-4 is capable of vibrating windows and mirrors while delivering spot-on low frequency reproduction. The W3v3 subwoofers don't require monster amplifiers for adequate performance - anywhere from 150-500W RMS is enough to extract substantial bass output. The 12W3v3-4 sounds very different when used in a ported box as opposed to a sealed enclosure, so try to get a live demo of the unit before deciding which is right for you.