Tim... I have heard about this>>
http://www.soundonsound.c...9/articles/krkergo.htm It is supposed to be like ARC but it is a wired gizmo and costs a bit more but supposedly does the same or similar job. It stays wired into the speaker system and corrects in real time....
I looked at this, then I looked at ARC. ARC was about $200 at the time and IIRC this ERGO system was selling for around $500.... needless to say I went with ARC.
Might be what you are looking for though.