step 1 : apply 2 medium coats of f/g resin with crushed up matting to baffle allow 1st coat of f/g resin to get tacky then apply second coat.for this install i used a 5:1 f/g resin to bondo mixture

step2: measure baffle to proper depth ,i.e. these are used for door applications,so measure your mounting depth with the window down cut baffle to length

step 3 cut carpet ,should be medium dense fiber carpet (like speaker box carpet) to about 1/8" bigger than the hole you cut in the baffle. hot glue it to the baffle and you have this:

aperiodic vent enclosure!!!! these things worked great for my dedicated mid bass project in my doors .total cost about $30.00,hope it helps