How to do ali g's respeck snap?

on the HBO show da ali g show, he does this snap. its when ever he says the word respek or idk but it has to do with respek. i know that you take ur thumb and put it against ur middle inger and ur index finger just sits there then u whip ur hand forward. i can do it but i cont make it very loud. how do i improve the sound quality, lol.