I watched this the other night. A true hole-in-the-wall studio that turned out massive hits. Shag carpet on the walls. Dirty. In a warehouse district in Van Nuys (I think). Turned out tons of gold and platinum recordings by Fleetwood Mac, Tom Petty, Nirvana, Rage Against the Machine, Neil Young... many others.
http://buy.soundcitymovie.com/ Proves you don't have to have state-of-the-art facilities. They did however have a "magical Neve board". Of course, we all have Neve equipment don't we?