YHR from teh looks of your IR detector filter, maybe the gaps of the filters could be a little big? so far I have mine set up with gaps of 1.5 - 2mm and a total of 4 disc shades to try to mimic the TBUs and have been hit outside of 40ft. Also in my own test, the DBC IR emitter seems to have the same range hitting tam tanks if not a slight edge.

I feel that the variance in range you get should be more tied to the receiver than the emitter.