Room correction altering soundstage

I purchased a Tact 2.0 room correction processor two months ago. after setup and listening, I really like how the processed curves tame the boomy bass, but I have lost the middle of the sound stage. Vocals for instance, which unprocessed, are centered, now come from each speaker with a disconcerting reverb effect. I suspect the delay programmed in during setup (18 ms) to be the culprit. Does anyone know if 18 ms delay between speakers is enough to produce audible effects?

Thanks in advance,

Dave