check out http://www.acapellas4u.co.uk to get some quality acapellas to popular songs.
Obviously you can use your EQs to trim out Highs and Lows (sometimes it work sometimes it doesnt) to help boost the vocals.
Also, try messing around with the High Pass and Low Pass filters (in combination) in ITCH (effects)
It may be easier for you to take a song like “Wild Ones” where the intro is almost all vocal and overlay that and fade into the beat starting… I use this a lot in my mixing.
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