The Gate (1987)

When Al (Christa Denton) and Glenn's (Stephen Dorff) parents (Deborah Grover, Scot Denton) leave town for the weekend, Al uses the opportunity to throw a party while little brother Glenn and his friend Terry (Louis Tripp) decide to explore a hole left by a tree-removal service in the backyard. When unexplainable phenomena begin occurring, Terry -- with the help of his extensive heavy-metal music collection -- comes to the conclusion that he and Glenn have accidentally opened a gateway to hell.