Thiel Owners

Unsound - setup is complex. Jim/kathy left installation to dealers with little support. Those who excelled at the nuances of setup sold the lion’s share of product. 
since bass is quite omnidirectional I first position for best bass. Since mid frequenci s are semi-directional, set tow in for best blend of direct and reflected energy. Timing is most critical between mid and tweeter, tilt directly affects that arrival integration. Note that more back tilt is required the more straight ahead the speakers point. Analysis via REW, etc. can help find the best formed step response which identifies proper tilt. 
BYW, most folks tow their speakers in.

@tomthiel  Thanks for the tip re: tilt back and toe in ( or the lack there of ).

I hope you’ll indulge me if I return to the subject of placing identical Thiels back to back; what might be a typical minimum distance from the rear firing speakers towards the front wall as seen from the listening position?

No simple answer, it all gets much more complex when supplementing the rear wave. Four to five feet behind the far tweeter separates the direct front wave from the reflected back wave by around 4 milliseconds which is enough to perceive the rear wave as a reflection, rather than conflating it with the front wave to be interpreted as smear. 
When space is insufficient such as the new lab I’m building in the basement, I am resorting to a diamond rather than a square room. By turning the axis 45 degrees, the return paths of the upper frequencies becomes much longer, and the wall bounce spreads out in time. You also get more distance behind the chair. In my case of a concrete corner vs 2 stud walls, We gain launch symmetry. The distance requirement behind the speakers becomes nearly moot due to the new reflection geometry. It solves many pesky problems if you can make the diamond layout work in your life.

Back to square launch, the right distance is when the mud of multi point launch becomes articulated clarity of separate primary and reflected signals. It’s obvious when it happens.

In case anyone is interested, Decibel Audio in Chicago has listed a pair of CS6 on Audiogon.  They are asking $2199 plus shipping.

https://www.audiogon.com/listings/lisbf730-thiel-cs6-floorstanding-speakers-in-natural-wood-finish-w-manual-crates-beautiful-full-range

jazzman7

Good catch! I hope those CS6 speakers find the next home.

Happy Listening!