nautilus 801 soundstage accuracy

I've been trying to get 801's working properly for a while now. The bass has been a diffucult but is coming along after building many bass traps and insulating the ceiling and bulk heads and covering it with fabric. I'm also waiting for a new solid state pre amp wich I think will help.
My question now is how important is the correct tightness of the slotted tension tube at the back of the midrange unit to reveal the correct midrange and soundstage.. Joel
This is the information I got from B&W when I asked the same question:

"Thank you for purchasing B&W! The midrange tension on your Nautilus 801s can be set by simply tightening the bolt to the point where there is some resistance, and adding another quarter turn to secure the bolt without over tightening it. If you set the midrange tension on your speakers accordingly, you should be fine."