How far should you be sitting from your speakers?

You've got the speakers beaming at your ears. Experiment with cutting down the angle ever so sligtly a little at a time until you get out of the hot spot.

IK pink noise tone? Not sure what the poster had in mid. IIRC pink noise has equal SPL per octave averaged over time vs white noise that has equal SPL throughout the bandwidth. The effect of pinking noise is to reduce the level per Hz at higher, broader, octaves, demphasizing high frequencies. Like white noise, pink noise can be band limited. By its very nature, the instaneous level of either noise source is variable. The balistic response of a sound level meter is often set to slow, so it integrates the flutuations to obtain a more useable reading. Perhaps the poster had in mind narrowly filtered pink noise, but the tighter the band limit the more variable the level balistics.

db

Pure simple test tone 1K pink noise. available from many test cds ect. When properly spaced ect there will be air around and behind the "ball of sound" Be sure to use a movable chair to find the correct lock in point. This will bring imaging up to parr and will do nothing for optimum bass responce so you results will be used as a starting point.
One could use a mirror to find the refelction points on side walls ect to place sound absorbing material at that point to help with reflections.