I use 2.75" automotive trim screws for my 75 lbs 18" subs. That way, they come with their own washer on them that doesnt come off and makes a nice mechanically anchored fit. Drywalll screws kept backing out //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif