Acoustics, by the way this plays a HUGE part in what your hearing. First off running one speaker in one corner at time, lets imagine your cranking your stereo and a channel goes out, blows whatever.. What does this sound like? CRAP regardless how good the components used are! Fact is your missing now the Center image in the room, and yes DISTORTION goes up substantially because you hear all the artifacts of the room on that side no longer being integrated and even cancelled by the other side of the room
Also Recordings for example, I can play one that is very GUITAR heavy to the left channel lets say, cut that speaker off and the right losses a bunch of the info in the right. Vocals foget it, Midrange forget that too as you cannot have a warm centered voice and sound stage in the room anymore because your missing a channel. Bass as well now you are OVERLOADING one side and it sounds like Crap.
So again I would like to know how this is an accurate style at all for really evaluating true hi end stereo 2 channel? Also just a note, I believe you are evaluation CORNER horns? This is even worse, they are only echoing out of one corner or the other, No breathing room as they are smack dead in your corners, so yes you basically would have a boom box blasting at you from one side of the room evaluating one Crossover at a time vs. Stereo.
So please you have spent the money, its time to get the Pairs to make your system work correctly and you might find that all this back and forth is not necessary and you will get a great sound already. I understand the stuff is expensive, but you chose to get into this in the first place, so its best to do it right at this point, doing yourself a huge favor getting a true balanced sound all together, and no doubt 2 channels with a "Sonicap" will sound better than ONE with a duelund :-)