Dipoles are characterised by their "polar response" which is the frequency response shown at different angles from a speaker. A polar response plot will show how a monopole speaker has omnidirectional bass, but where treble is aimed forwards. A dipole fires the sound out the front and back in a directional manner, with a null on the sides. There are two types of dipole speaker:
- open baffle dipole where a driver is mounted on a baffle
- box dipole where identical drivers are placed on opposte sides of a box with reversed polarity
