This is what dipole energy distributon looks like in free space with the dipole facing left and right:

In general, there will be less energy at the sides and more energy front and back. Then, when in a room, reflections off the rear will combine with the front wave to form a complex pattern, some places and frequencies adding together and others canceling out. If the rear wave is completely open to free air or absorbed completely, then the front wave should be the same intensity as a monopole.