"One popular misconception regarding phase inverters is that as the frequency decreases, the front radiation from the cone becomes less, and all the acoustic power heard emerges from the port. Actually, the very best that can ever be achieved would be approximately equal outputs from the port area and from the front of the cone, inasmuch as radiations from the port are directly related to the movement of the cone." The authors go on to opine "there is slightly less acoustical power from the port area as compared to the front of the cone because some energy is lost via absorption inside the enclosure", but they offer no supporting data.