The R/T 318/328 enclosure series features our Labyrinth Slot Vent system. This venting system is a form of “porting” on a much higher level than just cutting a hole in a box and dropping in a port tube. The Labyrinth Design increases the amount of bass your woofer produces without needing any additional power from your system. The “MAZE design of the Labyrinth Slot Venting system brings a controlled sound level increase by allowing long, low frequency sound waves to easily escape, while short high frequency waves remain trapped, unable to cause unwanted cancellation and distortion. In turn, this gives you loud clean bass a sealed or basic port design cannot deliver. The 318/328 enclosure series also includes our Quad-Lock joint construction, which is a four step process re-enforcing all box joints with computerized dado’d grooves, ultra strength wood glue, staples, and caulk.