The D-12 is a dodecahedron-shaped speaker produced from around 1973-1982 by Design Acoustics, and was designed by it's founder George Sioles. Only a few hundred pairs were made, due to their high production cost, which has made them quite hard to find. Essentially a 3-way system, it has 11 drivers - 9 Peerless 2.5" Peerless tweeters, 1 Peerless 5" up-firing mid range speaker, and 1 10" down-firing CTS woofer. The 12th surface is a port for the woofer, located on the bottom half of the 'orb'. These speakers are 30" by 22" wide and weigh about 50 pounds each. The sensitivity is 91db and frequency range about 30 - 15,000 Hz. The grilles came in black, avocado, blue, gold, and mandarin! They received a particularly dazzling review from Julian Hirsch of Stereo Review in 1973.