The Tact microphone is only used to measure room response without any digital correction, we call this "measured response".
We can display the "measured response" using the Tact software, unfortunately it wasn't shown in the picture above. Then in the Tact software, we define a "Targe curve" or "Target response", this is the curve displayed in the picture above. The Tact software will then generate a digital filter (we call this "correction filter") by looking at the difference between the "measure response" and the "Target response". When we play the music, before the digital signal gets to the DAC card, it first get "filtered" by the the "correction filter".
I don't know if there's a way to use the same microphone to measure the "target response" after you've applied the correction filter.
I'll posted a picture of my room response and the target curve when I get home tonight.