Hi Fatparrot,
I thought I did explain the venetian-blind effect, albeit succintly: "I am talking about the noticeable discontinuity or abrupt shift in the image as you move you head from side to side."
Let me try again. With cone/box speakers, as you move your head laterally, say slowly from left to right, the center image such as a singing voice will remain in the center for a while, say for six to twelve inches; when your head has moved far enough to the right, the voice will shift to the closest (right) speaker.
With most dipolar speakers, i.e. planar speakers producing sound to the front and to the rear of their diaphrams, if you move your head just a few inches from left to right, the center image will suddendenly disappear and then reappear slightly to the right. This effect will continue as you keep moving your head. Now you hear the center image, now you don't, and now you hear it again, similar to the way you see only between the slats of a venetian blind: thus the "venetian blind effect." So to get a stable image, you must keep your head stationay, locked within a few inches of the listening center.
This sounds far worse than it really is. And the Maggies aren't certainly the only speakers to do that. All dipolar/planar speakers do, some more than others. In other words, they all have a relatively small sweet spot compared to cone/box speakers. This sweep spot gets bigger with each new generation of the Maggies and is quite large with the Soundlabs.
The venetian blind effect can be quite disconcerting to some people. When you are within the sweet spot, however, the sound is vividly three-dimensional and truly magical. That's why I continue to have a love-hate relationship with dipolar speakers.