I'm curious as to which level of the program would be good to get. I'm looking at Level 3 & 4 in particular. As for differences, I see you get 1/12 and 1/24 Octave bands as opposed to 1/6 in Level 3. The Level 4 also has white noise. Are those really worth the extra $30? Please don't just say that as long as I'm spending that much, why not get everything? Kind of a lame reason in my eyes.

Also, how would you get an amplifier's output to show up on the oscilliscope section? I'm more interested in this program for tuning my car now than the HT as my HT is space and setup limited. Gain setting is very important in the car. I think I see how to test the RCA outs of the head unit just by using the RCA's and run that to the computer, but I'm not sure about the speaker outs of an amp. Some of these send quite a bit of power out. Don't want to wreck the computer somehow.

soundhound, what does your USB interface with?