Flatline Audio owner/producer Dave Otero has announced a new festival called Flatline Fest. The event will take place at the Oriental Theater in Denver, CO on June 13-14 and it will feature the following: June 13: Archspire, Aborted, Nuclear Power Trio (live debut), Inferi, Of Feather And Bone, and Clusterfux. June 14: Cattle Decapitation, Allegaeon,…