California Audio Technology (CAT) have built the worlds most expensive in-wall speakers for the price of 110,000 per channel. The speakers feature 3 custom made 22-inch aluminum cone woofers placed on their individual Avonite panel, also include smaller 8.5 inch, and 12 inch subwoofers which lend thrust to the bass output, 5.5-inch midrange aluminum drivers and single 1-inch silk dome neodymium magnet tweeter, for refining the sound output.

The speakers will have separate amplifiers for each woofer, and can be controlled by a special connection rack that feeds into it. The speakers seem to have 7 times the intensity of normal woofers which can only played in open and spread out in its dimensions, or else will have negatively colossal.

Source: bornrich