Had a similar experience back in college in the 1970's. Me and my roommate both had unusually good systems for the day, and running both together was the best.
Didn't know it then, but now I do, that a lot of this was due to the fact that multiple drivers in different locations is by far the best way to get good bass response. Notice that is what you are hearing too. 50 years, physics hasn't changed. Not one bit.
Which is why, when you advance from lamp cord and freebie rubber power cords, low-res stuff in general, and learn to set things up better, then you will notice those multiple speakers really are messing with your imaging. Because: physics. Still hasn't changed.
Didn't know it then, but now I do, that a lot of this was due to the fact that multiple drivers in different locations is by far the best way to get good bass response. Notice that is what you are hearing too. 50 years, physics hasn't changed. Not one bit.
Which is why, when you advance from lamp cord and freebie rubber power cords, low-res stuff in general, and learn to set things up better, then you will notice those multiple speakers really are messing with your imaging. Because: physics. Still hasn't changed.