JBL tweeter adapter

The tweeters on a pair of Sansui S-1000U speakers were blown. I got tweeters off of an old pair of JBL tower speakers. These JBL tweeters are too small for the hole in the Sansui which is for 3.5" tweeters
This adapter is to close the hole and keep the speakers sealed as they are a non-ported sealed system.