DR. BILL:
If you placed a subwoofer in a corner, should it be "toed-in" like a Klipschorn, and if so, should it fire outward or into the corner. Or should it be squared to the corner. Again, should it face the front or side? Or perhaps it doesn't matter at all?
After years of wrestling with subs for pannel speakers (Maggies, Quads, and etc.), I have few thoughts to offer. As one of the poster had stated, bass signal below ~40Hz is non-directional. However, smooth integration with main speakers (in this case K-horns with such a high efficiency) would be a challenge. Having them in the corner or other room boundaries would produce max output but further away you go from your main source, there's timing issues that may be a bigger problem than lack of volume.
I am not sure yet but K-horns do go down to ~35Hz then the crossover point should be around 40Hz at highest slope possible (24dB/Oct) and play over the main speakers.
The best main/sub integration I have experienced is Quad ESL-63s and Gradient SW-63subs, playing the main speakers high passed at 100Hz and having the Gradient subs physically located right below it.