Air Conditioning - Humming/Vibrating sound from central AC

I'm having trouble with a central AC unit. It makes a loud, resonanting vibration/noise that I can feel through the floorboards of the house. It only makes the noise when its blowing air (and the air is perfectly cool). Its a cyclic humm that starts off kind of slower and then speeds up a bit.

My problem is I'm renting this place and I called maintenance but they said all the AC units sound that way and theres nothing wrong with it. I know they all sound that way cause I can even hear my neighbors units after mine shuts off :( Its driving me nuts! If someone can please give me suggestions on what the problem might be I can go back to the propery manager with someone more than just 'umm, its annoying'

Also, is there anything I can do to service it myself? Thanks for any help!

Are you able to get to the furnace, and the line sets?

Most rental place uses the cheapest equipment they can get thier hands on, and lot of time it's not going to be quiet as the upper priced brands.

But if you can get to the linet sets, and see how they are fasten to the joist.