Aggressive kitty (the showdown of the males!)

I am the proud mama of a 2.5 year old male (neutered) tabby named Dante. He's always been a very friendly, affectionate and snuggly cat. He never leaves my side and his favourite place is sleeping next to my head on my pillow. However, my roommate recently got a young (4 mo.) rescue cat, who is also male. I expected a certain amount of hostility, while he adjusted to no longer being the only kitty in town, but despite being in another wing of the house and the kitten being behind 3 closed doors, he won't come near me, and growls if I so much as touch him. I've heard from many that male cats who are neutered will eventually learn to tolerate oneanother, but if one is still unneutered, does that discount everything?
The other cat is getting neutered next week, so we're hoping that'll help. What confuses me is that HE is perfectly content... shouldn't he be the scary hormonal one?
Is there anything I can do to put my kitty more at ease? I hate seeing him so stressed out. Plus, I miss our cuddles.
Thanks!

I have 3 males of various ages living with me. The last boy I brought in, Nino was not a cat friendly cat but I had to have him :) He's a huge silver tabby Maine Coon. Anyway's I kept him seperate for about a week, then started leaving the door to his area open a bit and just let him come out and poke around and then I'd put him back after he'd had a bit of out time. Now the resident two boys were a bit stressed cause he tended to be a bit on the aggressive side, chasing and smacking and screaming!! So I discovered calming collars, they have a pheromone and lavender in them. So I bought one for everybody and they really worked well. Took the chasing and stuff down to a manageable level and everyone was able to chill out. I can't remember exactly what they're called but you can get them in Petsmart. They're purple. So fast forward a few years and two years ago I rescued a female kitten, she spent the first little while seperated until her vet visit and an all clear. Now I think because she's female, everyone accepted her pretty quickly and other than going into heat...wow!! (never again!!) That and being a kitten, they put up with alot from her. So I would try the collars for both the kitten and your cat.

I'm experiencing some aggression issues lately too. I have a 4 month to 5 month kitten unaltered and Bobby who's close to 1 year that hasn't been neutered yet who are brushing with violence. Bobby wants to play but the Cow hates playing with poor Bobby and hisses and growls big time on the other side Boris (2 year old neutered) has begun to show strange behavior like going in front of my dad and pee in his bedroom right to his face, a cat who has always been clean I'm guessing all this is due to having unaltered males at home (since Boris is perfectly healthy) I'm hoping this all goes away as soon as we have a neuter/spay fest (also have a 6 month old tiny female that looks like a little kitten she hasn't been in heat yet but she needs to be fixed soon too. She's petite, she's healthy it's just she's tiny)
Keep us posted to know if that's what's causing trouble at your home.