Subwoofers are known for shaking--some vibrate so much that they can crawl across the floor like a decades-old washing machine. "We built two opposing drivers, which move the air to cancel out the force inside the cabinet," says Mieko Kusano, Sonos's senior director of design. "You can literally put stacks of cards or glasses of water on it, and they don't move."
Because Sonos wanted the Sub  to be svelte, it couldn't have a thick compressed wood shell like many high-end subwoofers do. Instead, the company developed a plastic resin that begins in granular form and is heat-molded to the desired shape. "It doesn't vibrate, and it can be just a quarter of the typical thickness of wood," Kusano says.
To create a crisp sound and prevent muffling, Sonos's designers built these ports into the subwoofer. "The hurricane-like swirls take all the interior energy and push it out," Kusano says. "This allows us to get a cleaner sound, but also keeps it compact and at an acceptable price point."
"Most subwoofers are cubes, and I don't know why because you can't do anything with that--you can only have one orientation," Kusano says. The Sub's shape was designed to be flexible: Not only does it work laying down or standing up, but users can place it against a wall or shove it under a sofa without hurting performance. ($699, sonos.com )