I found the the auto setup to be pretty accurate however I decided to buy A SPL meter from Radio Shack for $50.00. This model had is digital and received a pretty good review from one of the internet forums that I was on. It simple to use and I was more content to know that my system was a little more accurately calibrated when using the meter.

If you have the funds I think that it is worth the invest.If not the 990 does a very good job.