Live room EQ tuning

[Merewether]

I would like to be able to manually adjust (in real time) the main output EQ like what happens when you 'pink' the room. I am proposing the following method to do this:

A) Select two channels that are: 1) The main output from a mixer 2) A reference microphone in the room
B) Measure the time difference between the main output and the reference mic and apply the delay to the main output to align the two signals.
C) Apply the octave FFT to each signal with an appropriate averaging filter.
D) Subtract the two signals from each other and display the difference (display the room minus the main so that you know to turn up the channel gain if the difference is negative).