There isn't much to explain about Yuki Yamamoto's Spica, just unveiled at Tokyo's DesignTide 2009: Composed of a water-tight subwoofer and a glass tube, the speaker is covered in lights and water. When music is played, a leaping light show, which plays across the ceilings and walls, mimics the sound. To appreciate the full effect, sit back and enjoy the video.

For a similar idea, check out Arnaud Lapierre's haptic speaker designs. A taste:

[Via DesignBoom]