My wife is a LEO, and from the stories she tells, folks refusing to answer the door is fairly common. SOP is to secure the perimeter so that nobody can sneak out (easier than it sounds - you can do this with two officers if they are posted at opposite corners of the perimeter), and then obtain a warrant. It’s a PITA, but it ensures compliance with the Fourth Amendment.
The officers who responded to this particular noise complaint could have explained that to the students. Something along the lines of “you can turn the music down, and everyone’s happy, or you can be a jerk and force me to get a warrant. If I have to get a warrant, you’ll get arrested on the noise complaint, I’ll breath test all your underage guests and arrest any who’ve been drinking, and I’ll confiscate your stereo system and speakers as evidence in the noise complaint investigation. So what’s it going to be - the easy way or the hard way?”