I think it is essential to have a setup disc and an SPL meter to properly calibrate your system. The cost is negligible when you consider the amount you've spent on hardware, and the greater amount you will spend on software.

I use Avia and the Radio Shack analog SPL meter. A very wise investment, and you would be surprised how inaccurate your ears can be. I know that calibrating by ear was wholly inaccurate in my case.

Good luck!

-Nick