Room size is very important to realize the best from nearly all Duntech/DAL speakers. I've heard them in smaller rooms and in larger rooms and larger was always best.
First, the 10' seated distance from the front baffle that Rcprince mentions. A cornerstone of Dunlavy designs was time/phase coherency. He achieved that with physical set-backs of the front baffle, heavy wool felt damping, and crossover design. For any of his 3-way (or 4-way) speakers, that minimum of 10' is necessary for correct/cohesive arrival time of the drivers. You can listen closer but they will not sound up to their potential.
Second, sidewall distances can be critical and affect clarity. John seemed to prefer long wall placement and I always suspected that was to allow more distance from speakers to sidewalls, even with wide channel separation. And BTW, I've heard L/R from 6' to as much as 14' and with careful set up and a good room, wider can be spectacular. I've heard amazing fill between the speakers and a huge soundstage, but "no hole in the middle" with some wider separation.
Lastly is distance from the front wall. This will be governed by you room and your desired bass response. Every situation may be slightly different but I'd expect 3-4' out from the wall will be minimum.
Where I always disagreed with John was his preference for long wall placement with the listener against the back wall. In my experience at least 3-4' distance is also necessary for the listener's head from the wall to avoid heavy, slower bass.
So they many not be easy but the musical rewards can be exceptional.
PS - A few years ago John Marks reported in Stereophile that Sony Studios NYC went to the trouble of bringing in a new pair of Duntech Princesses from Australia. Considering that Sony makes their own high end speakers that says something I think.
