Following on from Jay Jennings' post, How Did They Do That?? Vol. 1: The Predator “clicks”, I thought I'd carry on the series with another classic, iconic sound - the Ghostbusters Proton Pack powering up. If anyone knows how it was done, please share your wisdom with us. And if there are any other Ghostbuster related sound knowledge why not share it here too. To give you a taster, check the video. There's a good example when they are in the lift (1min51sec).