Tannoy Proto-J Reference Manual page 8

Another interesting note, the Tannoy true Point Source Dual Concentric™ monitors are free from the
physical offsets previously described, which means that the behavior of the Dual Concentric™
montors will not change in the horizontal, vertical or any other plane you can pick. The other neat
thing about Dual Concentric™ monitors is that no matter how close you get to them you can't get
the image to fragment into separate high and low frequency sources.
Wit h Dual Concentric™ monitros, there are no changes in the relationship between the woofer and tweeter,
you have complete vertical and horizontal freedom of movement.
Now, if you were to follow the all too common practice of lying your two way monitors on their side
to give you better sight lines over your meter bridge, you can see (and hear) what will happen. With
the monitor on its side, moving your head horizontally means you are now moving through all those
rays, or lobes, where the wavefronts from the woofers and tweeters interfere with each other. The
midrange frequency response will be different for each head position. All two way component moni-
tors, no matter who manufactures them, need to be used with the multi-driver axis vertical (that's
just the way it has to be when you're in the nearfield). And if you're wondering how three-way near-
fields work with a whole bunch of speakers stuck all over the baffle, well... you'll quickly realize why
we stopped at two way speaker systems.
LEFT
BAD
RIGHT
GOOD