Here's a vocal doubling plug-in that has all of the right features! DUO Evo by Antares makes getting the perfect vocal double easy. Just insert it on one of your tracks and, a few tweaks later; you'll have the vocal double you need! DUO Evo lets you dial in almost every aspect of your doubled vocal, including pitch variation, timing variation, and vibrato. DUO Evo even includes a simplified version of Antares THROAT Evo, giving you powerful one-knob control over the timbre of the doubled voice. So, whether you want a more masculine voice with flat expression or a feminine voice full of vibrato, you're set.