thanks for the replies (everyone!). That's fantastic about UHBIK, I didn't know them at all. Since Logic covers the basic surround options (as you said, Billy) compressor/limiter, delay, reverb, I was just looking for other options, filters, delays with more extreme options, more reverb possibilities. I have an exhibition opening this week with three different 5.1 pieces, one in each building (abandoned kilns in a park in Sydney) and I'm just trying to get more movement out of one of the pieces in particular. I've never learned Max, which would be a smart thing to know in this instance for sure. Again, thanks (and any other suggestions for future reference of course welcome)