Hi Maukoal, and welcome to the website!!
First of all, I appreciate you searching for answers for your problem and I'm positive that you will find the answer. If I understand your situation correctly, you are living in an apartment with four dogs. I think you are pretty lucky that only one of your dogs is barking uncontrollably, which leaves your job easier to train only one dog!
Do you do anything to stop him from barking when you are home? If you don't, then you will have to address that first, by correcting his behavior. Personally, I do not allow any barking in my household from my dogs, friends and family walk-in my house without a word from them. What I have done is to give a scruff whenever my dogs would ever bark, but I have done that since they were puppies so they learned early on.
Your dog’s behavior pattern will be harder to break since he has gotten away with it for so long – think of the nanny show when she tries to put a kid to the naughty steps – she literally has to put him back 50 times for the first time, and 30 the second and so on, eventually the kid stops resisting.
Eventually when you get comfortable with this, you can set-up scenarios where a friend could walk in front of your house, or knock on your door and test your dog’s reaction, reinforce him when he isn’t barking and give him a fair correction when he is.
Another thing that bothers me about your post, is the sentence “i try to take him out when i hope no one is out” … I understand that your dog might not be the best behaved dog, but keeping him away from a situation where he gets overexcited is actually the worst thing to do. The more you bring him to see people, and the more he is around people, the more comfortable he will become. However you should also stop any unwanted behavior at that time also.
Hopefully this helps a bit, and maybe Lonewolf can give you some more pointers I can’t think of right now!