Is Bass Non-Directional In A Two-Channel Rig?

The basic anwser is yes, bass is non directional in an any channel rig, but at different frequencies for different people. Some people start loosing the ability to discern where bass comes from as high as 120hz, by the time you get to 80 hz, no one can tell where it comes from.

Mitch4t,
Sorry, I just realized that I did not completely answer your question... Also yes, you can put a sub behind you. Back at Marcof Electronics seems like 300 years ago, we had our own sub design. We buit an 8, 10, 12 & 15 inch model.. At some time or another we had tried each of these sitting right behind us, Maybe 2 feet, while the speakers were about 8 feet in front of us. Once spl was matched, they all worked well, undetectable.

08-15-11: Theaudiotweak
"You can hear where the bass originates even below 40 hz".
Well maybe if crossed at 40HZ @ 6 db per octave, maybe, but crossed @ 12, 18 or 24 db per octave. I wish that I could quote some test somewhere, but I have had hundreds of people demo subs that had no idea where it was, even when sitting on it crossed @ 80HZ @ 24db per octave.
I guess it is possible that your hearing is more sensitive at those frequencies than others or you could be dealing with room nodes???
No disrespect intended, its just that we have tested this theory countless times.
I have seen cars rattling windows a block away and no one could tell where the boom came from until it drove right past us...
Have you done some testing to substantiate this?

Thanks Tom,
As you might expect, I've got quite a stash of Marcof innerconnects, I also use our speaker cable. We experimented greatly with litz, different braids, wire guage etc. I am using some that we never manufactured, but they are closer to what you have than the blue (se) models. Ed still says he still has PPA-2 head amps. They were a significant step up to the PPA-1 that sold so well. I agree completely about stereo subs, I just haven't heard one crossed @ 40hz that was directional. You may be one of the select few that can recognize this.