No_regrets, you make a VERY important point concerning room matching.
As I've mentioned before, I owned a pair of Duntech Princess (older sibling to the SC-IV and IVa) for 19 years. During that time I heard the Sovereigns maybe half a dozen times, at the CES, at dealers, and in private residences. I always preferred the overall presentation of the Princess because it seemed the Sovereigns required a larger space. Several factors are at play here.
First is the appropriate listening distance to allow the drivers to integrate. The manual for my Princess stated that all measurements were taken at 3.5 meters. That told me John Dunlavy believed this was the minimal distance for full integration. The DAL SC-V and VI and the Duntech Sovereign are all taller so may require even greater distances to optimize.
Second is the distance out from the front wall. After measuring for smoothest bass response I ended up out roughly four feet. I suspect the Sovereign and SC-V and VI require more distance because of their additional bass drivers.
Third is the distance from sidewalls. My room configuration only allowed about two feet from the wall for the right channel (much more for the left). I had four friends who owned Princesses and they all had greater sidewall distances. Their soundstage and imaging were all better than mine. I've always believed this is why Dunlavy often recommended long wall placement - to allow greater distance from sidewalls, thus providing longer delays in sidewall reflections and therefore better resolution.
Now there will always be someone who says, "my SC-IVs are in my den/bedroom/other limited space and they sound great". I would not say they don't. But I believe they would be BETTER in a larger room.
So whenever someone considers Duntech or DAL speakers, cost will not be the only factor, appropriate speaker to room size should be accounted for as well.
