tfoth, I've had my listening position as close as 6' from the DI's with very good results. My DI's are 6' apart and I now have my listening position about 8' away. The DI's allow for a lot of latitude with regards to positioning, room size and listening positionI Cannot remember where i got the info but, the distance that your speakers are apart , center to center Multiplied by a factor of 1.3 to 1.4 equals the ideal listening distance from the speakers.
I think mine are 79 inches apart and my listening position is about 103 inches from left speaker to listening position and 105 inches from the right speaker to the listening position.
The math says that it should be 102.7 to 110.6 inches