Honestly everyone I know the cold front makes sense for losing a voice (I sing as well), but just in general, David needs to do something about his voice.
Before I get flamed, David is my favorite singer ever so I'm not here to bash him. It seems as if every tour cycle goes by, his voice keeps getting worse and worse in general. Ive since some vids of Ten Thousand Fists from some recent MaaW shows and, to put it simple, they are bad. They haven't even been playing Stricken at there recent shows, probably cause it would kick the shit out of David's voice. He is losing his grit and his voice keeps cracking a lot more often.
One of the problems is like Bound2Fate said, is that they are touring WAY too much for David too keep up. He is getting older and the singing he does is NOT easy by any means. Unfortanely, they its hard for them to "tour" less because many large festival tours have many dates (like 5 or 6 shows a week, some 3 in a row, for 2 months) and a festival organization is not gonna want a band that wants to tour less, as this would bring is less money. Its all about money.
After the Asylum cycle, David should honestly just go to Melissa Cross (his voice teacher, she is VERY good) and practice his ASS off for a few months. Not a few days, I'm talking months!!!!!
Like I said I'm not here to bash David, I just want to make sure my favorite singer doesn't destroy his voice.