No, WITHOUT flipping the polarity of the wiring, the speakers are in phase (they move in the same direction), and if the listener is not exactly equidistant from both speakers, then the sound from each speaker arrives at the listener at slightly different times.Don't you just flip the pos/neg on one of the speakers in a 2 x 12 to make them in
phase rather than out---thereby eliminating the comb filtering?
Since every frequency has its own wavelength, that means that the timing difference of the two sounds arriving at the listener will occur at different points in the wavelength for each frequency. Some frequencies will therefor cancel out, and others will reinforce.
If you flip the polarity of one of the speakers, all it will do is flip WHICH frequencies are cancelling vs reinforcing.
Due to the wavelength of low frequencies being larger, there is a greater area/time of coinciding air pressure between the two speakers' projection at low frequencies, thus the lower the frequency, the more likely it will be heard as being reinforced between the two speakers. Flipping the wiring polarity of one speaker would therefore actually cause a noticeable drop in low end.