I want to be able to process audio files or synths to create new drones and textures in Logic Express 9. Anyone has any suggestions of which free plugins are worth a try?
Paulstretch is great for creating long, evolving textures and drones out of anything. Guitar riffs work incredibly well if you want a place to start.
Logic also has a convolution plugin called Space Designer, great for convolving two sounds together. An interesting combination you can try out is having the sound of fire crackling be your source audio and a synth pad as the AUX sound. Process with some delays and reverbs for added warmth.
Michael Norris' Soundmagic plugin suite has an FFT dronemaker included. I've gotten some pretty good stuff out of it.