Im currently putting together my audio system from used parts nothing spectacular but mid range stuff. Now do to wife requirements nothing can be visible so I've purchased 5 SpeakerCraft Aim8 threes that will be powered by a Denon AVR 2113CI . Problem Subwoofer Since nothing can be visible I plan on hiding the subwoofer in a cabinet that will be part of my new fireplace (photos below). Question is should I build my own sub enclosure into the fireplace and add a sub amp or should I create a shelf and place a powered subwoofer into the space (ex. SuperCube 2000). If creating an enclosure is the better option can somebody point me in the right direction to a forum post or a list of recommended components to purchase in order to build an enclosure. Below are the pictures of the fireplace I'm building and the space where I plan on building either a shelf or speaker enclosure. Its 11 1/2 inches wide. I appreciate any help you guys can provide thanks.