I was wonderering how you could use it as a spl meter.. When I used a real SPL Meter according to the Pioneer user manual , it said use the test tone and hold the spl meter at ear level at the sweet spot , which sadly enough is almost the center of the room since i have wall to wall couches and recliners.. Set at 78db according to manual.. So I did and my Rear surrounds and right and left surrounds seem a little loud .. So I found tru rta and thought it would work as well by setting up a mic in the same spot as the spl meter but I get different reading.. Oh well maybe I should have asked has anyone used TRUERTA and how they like it .. I am going to play with it more today and I still have the RS SPL meter that I borrowed so will see what happens.. Thanks for any help..