is 100% air tight.
Make sure you use T type nuts to secure the woofer. DO NOT USE WOOD SCREWS. At home depot you can get a nut which has spikes point back toward your screw. You drill 8 holes for the subwoofer and then secure the nuts with the spikes in place on the inside of the enclosure. Wire your sub for 4 ohm and place in the enclosure. Now you torque down your screw in a figure 8 pattern to secure the woofer and (this is very important) create and air tight enclosure. With the spiked nuts you can tighten them extremely tight and create and nice sandwich seal for the subwoofer. After tightening push the subwoofer in, you should be able to feel it air tight. It should feel like you are pushing against a balloon. If it goes in to easy, then you do not have an airtight seal. You absolutely need this for good tight base. You will know when you have a good seal, when you push in that sub.
I like the connector you created.