FL Studio - Improved Wah Effect with only FL Plug-ins - Warbeats Tutorials
from http://www.warbeats.com : This is an older tutorial, but the method I describe should work just as well today. It's one of the cleanest and best sounding wah's I could make in only FL effects. The following link will take you a page you can download the preset and hear a sample of the wah in a song:
http://bit.ly/FL-WAH