Is this a new behavior, or has he done this since you've gotten him? Do you ever let him out/give him attention/yell at him when he's barking? It took Cannon 2–3 weeks to get over barking for the first 5–10 minutes of being crated (when we left the room) even though he would go in willingly because I give him plenty of treats. I basically just had to ignore the barking, and he stopped eventually. If this isn't a new development, your dog is healthy, you are doing all the positive crate training methods consistently (really delicious treats that will keep him occupied for awhile - see the post I linked to) and ignoring him when he does bark, I would say he will stop eventually. Does he bark if you leave him in the room alone as well, or just the crate - he may have some separation anxiety. You mentioned he was a new dog previously crate trained; he could miss his old family.
I know that dogs can regress a bit with life changes (moving, new family members, etc.), so it may be good to start from the beginning with a lot of crate training methods.