It's the playing head, right?

Possibly, you might be hitting the bass drum pedal too hard, but an Ambassador should survive that for a little while. I, too, have got a Remo Ambassador bass drum head, and it's been doing OK for about a year now.

Otherwise... I have no idea.

I do have a similiar problem... I've nearly always played the same series of cymbal (Sabian B-series). For some reason, after three years of playing the same styles of music, I started cracking cymbals like mad. I still do, some four years later. I can't find an explanation for it, but I'm willing to settle.