The best part of the Polk Audio CSW100 subwoofer is what you can't see, which is everything. No, the CSW100 isn't invisible, but this built-in floor/ceiling subwoofer is completely hidden from view.

While many subwoofers try to appear unobtrusive, you still end up with a big black box sitting in the corner of your home theater. Subwoofers are often hard to hide, so some manufacturers go to great lengths to pretty up their offerings, utilizing natural-grain wood exteriors with lustrous finishes. The CSW100 goes in the opposite direction. It is designed to fit under the floor, between wall joists in a wall, in the ceiling, or even in furniture. The only thing that is visible is a 4-1/2X14-inch grille that looks very similar to a heating vent.

The CSW100 is contained in a slot-loaded, bass-vented cabinet designed to be completely free of resonance and isolated from the home's structural elements. It has a 10-inch long-throw driver with a fiber cone that produces a frequency response of 27Hz to 140Hz, with a nominal impedance of 8 ohms. This is not a powered subwoofer, so you'll need to purchase an external amplifier like Polk's SWA500, which was designed with just this kind of application in mind.

The CSW100 installation process is rather complicated, but the subwoofer comes with isolation pads and all the mounting hardware required. However, before you start cutting holes in your hardwood, you might want to consult a professional carpenter. For the absolute in subwoofer concealment, especially in new construction, the CSW100 is a great choice.

Pros:  Only grille is visible after installation, good audio performance
Cons:  Installation can be difficult, requires external amplifier

Warranty
5 years parts and labor