No, it's the contrary - the cardioid pattern above 100Hz makes D&D less sensitive to placement changes than normal speakers, less interferences with the front and sidewalls!
In an anechoic chamber you are getting a semblance of cardioid pattern. However, in a real-life room such pattern will be perturbed by reflections. What you will actually get will strongly depend on the distances to, angles, shapes, and materials of surfaces surrounding the 8C. At least one such surface will be present because 8C
requires a reflective front wall.
A logical fallacy:
Step 1: Measure 3D sound pressure field in an anechoic chamber.
Step 2: Put the speaker in a highly echoic environment.
Step 3: Expect the 3D sound pressure field to remain the same.
Below 100Hz wavelength is so long that 30deg rotation is meaningless to reflections. "Monopole" speakers with same dimensions are omnipole up to around 300Hz, then gradually reach the directivity of D&D at roughly 1,5kHz
The rotation at the very least will affect the shape of the 3D sound pressure field in the mid-woofer frequency range (between 100 Hz and 1.25 KHz). In even wider range of frequencies, if we take into account crossover effects.
The half-wavelength at 1.25 KHz is about 14 centimeters. Changing a distance from a radiating surface to a reflective surface by that much may turn resonance into cancellation.
8C has three radiating openings operating in this frequency range. If rotated 30 degrees, at least one of them will be pointing to a reflective surface. In real-life rooms, at least two of them will be pointing to some reflective surfaces.
The result would be multiple images of a true sound object, which creates an audio illusion of a perceptually enlarged sound source. Some listeners like it. As others mentioned, similarly enlarging Bose 901 was quite successful in certain market niches.
