Bands such as Voivid, Kowloon Walled City, Torche and Weedeater aren’t household names, at least not in most households. They don’t sell records like Taylor Swift, but those acts and others who fall under the banner of thrash metal, stoner rock, sludge metal and adjacent sounds have fiercely loyal fan bases who are willing to travel to see their favorite performers and, just as important, be surrounded by like-minded music listeners. For the fir…