I've got a laptop and an RS SPL meter and I want to measure the frequency response of my 20-39CS+ in my room. I seem to recall reading of people connecting their SPL meters to computers and using some software to get an accurate representation of their rooms. I also need to download a test-tone cd for this. So, I need to know how to connect the SPL meter to my laptop, what software to use (free, if possible), and where to download a test-tone cd. Can anyone help me out?