Polk Pre-construction brackets attach to your studs or joists before drywall is hung. They designate the exact location, and exact cut space, where your loudspeaker will be installed. They give your electrician a wiring target, and give your drywaller a hole template. Pre-construction brackets add that extra pinch of energy-harnessing, super-efficient rigidity that a built-in speaker needs. One more step toward keeping your built-in loudspeakers vibration-free, with added efficiency and less audio print through (when sound bleeds through walls into adjacent rooms). They re the inexpensive alternative to our custom performance enclosures, and give you more flexibility for speaker placement.