Can xathrid demon in mtg's effect double?

so if i have two xathrid demons on the field, at the beginning of my upkeep can i sacrifice both of them and deal 14 damage to my opponent? heres a link to the card: a href="http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=189885" rel="nofollow"http://gatherer.wizards.com/Pages/Card/D…/a