The young males will have two little pimple like combs that show before the females start to show a comb. You will have to slick back the crest to see the little pimples. They will be found at the base of the crest near where the bill connects to the skull.
"...young males will have two little pimple like combs that show before the females start to show a comb"
That's how I could sex mine (and fairly early, if I remember correctly).
I hatched and raised some Spitzhaubens a few years ago. I think they are just beautiful.
Got pics?