Real quick a couple of easy experiments to try with suprising results.
The issue at crossover with two drivers emitting the same frequency can be demonstated with the help of a friend, two small speakers like a pair of pro II's and a pink noise generator.
Drive the speakers at a comfortable level with pink noise, have your friend hold both speakers, one in each hand right next to each other with the sides touching and the front faces even with each other while you listen 10 feet or so away. Have him (or her) slide one speaker forward a few inches then back and observe the changes in what you hear, and let us know. Some say on the alignment issue, if your going to miss, miss big. You will see why.
The issue with the effects of the room, or some of them.
While listening in your usual spot, simply cup your hands behind your ears (giving your self Micky Mouse or Dumbo ears) and note the difference when your not hearing as much of the back of the room. When you do that out doors (like if you have a patio system) the sound does not change that much, in most "living rooms" the change is , well,,, try it. You might end up with a thick fiberglass pillow for you listening pleasure.
I have a pair of Altc 604 8-G's that I haven't listened to in some time and do have the desire to set them back up and get active with them. My real job and life just keep getting in the way.
Best,
Barry.