Planetary Duality Vocoder

well, for start - which vocoder are you using?
most times it's needed to boost hi-end on voice that's going into vocoder.
 
- As nezvers said, try fiddling with some high-end EQ on your vocal track. Most vocoder plugins I've used have a set of EQ sliders for each octave in your voice signal... I usually cut out the one around 4k so there's no ice-pickiness, but keep the other high bands up.

- Make sure you're using a synth with lots of spectral content. The "noisier" your synth is, the more there is for the vocoder to work with.
 
You could probably get close with any decent vocoder plugin out there. I use the TAL Vocoder for some of these songs (and I double-track vocal harmonies on all of it so it's not just one vocal part):

http://thisisthetide.bandcamp.com/album/tidal

Just make sure you are pronouncing the words well enough, sometimes you really have to over-pronounce to get it to be understandable.

There are plenty of vocoders out there aside from the TAL one. I have two go-to vocoders, the TAL and this one:
http://create-music.net/pif-media-technologies-pif-vocoder/

Both are freebies and seem to do fine for what I want. You just have to learn the plugin and tweak stuff. Also RTFM, obviously.:lol:
 
Right now I'm using the Waves Morphoder and it's not really doing it for me. I'll try boosting the EQ and messing with TAL and PIF. Thanks guys!

EDIT: Guess I won't be using PIF. Forgot to specify I'm on a MacBook Pro.