Sonance started shipping its SLS HighOutput (outdoor speaker with below-ground sub) system yesterday. Available as a package with the below-ground sub, four in-ground speakers, the elbow and canopy and an amp (a Crown CDi2000), the SLS has a 15″ dual-voice coil stereo subwoofer, two-way satellite speakers and has an SPL level of up to 120dB at one-meter.

Check out all the specs here: http://www.sonance.com