I use the stuff from Siasoft; the software works really well and it is userfriendly.
Wow how much is that? Is it trialware or shareware?
You have to pay for this one but it is a comprehensive set of tools that you can use to tune your room, pinpoint trouble frequencies so you can pad your space accordingly, and even help calibrate microphones. I got both the Smaart and Acoustilive as part of a package to help design a room for tracking drums with my brother. I originally got this package because we got turned onto it during one of my acoustics and dynamics classes so it was a package I was familiar with, and knew how to work with from the get go. I got an academic discount on it for like 20% off the list price.