/cgl/ - Cosplay & EGL

So I'm making Nonon's Symphony Regalia: Finale outfit and I'm having problems with the hat. So far I've made the base of it from expanding foam; it's slightly too tall, but my main problem is that it's a bit top heavy, so it's not staying on my head very well. I'm might add weights to the bottom to remedy the top heavy situation, but do you guys have any other ideas for making it stay better?

pic related, already figured out how I'm going to do the harness for the speakers.