Among the additions are Five Finger Death Punch, who will co-headline the second night along with previously announced Avenged Sevenfold. "We're excited to take the new albums out on the road so fans can hear some of the new music live," said Five Finger Death Punch singer Ivan Moody. And what better way to kick off our fall tour than with a massive festival like Aftershock?"

Retro hair metal rockers Steel Panther, who will play during the festival's first day, are also set to kick off the festival at a pre-show on September 13 at Ace of Spades in Sacramento. The pre-show is free for all festival ticketholders.