When choosing a system, you may also be confronted by a choice of surround speakers â€“ direct radiating, bipole & dipole.
Direct radiating are the most common, projecting sound waves from the front of the speaker. This gives the listener a very distinct idea where the sound is coming from.
the classic KEF 'eggs' are direct radiating speakers
Some home cinema fans â€“ the boffins at THX included â€“ prefer bipole speakers, which feature two sets of drivers that project sound from the front and sides. Theyâ€™re designed to push and spread sound along the walls, which gives a more diffuse, enveloping sound than direct radiating speakers. The two drivers are in phase, which means they push out the air at the same time.
Dipole speakers are similar, in that they emit sound in two different directions creating a diffuse, non-localised sound, but the drivers are out of phase, which creates a â€˜dead zoneâ€™ in the listening area that makes the origin of the sound even harder to pin-point.
Let's take a peek behind the speaker grills next and take a look at the business end of a speaker: the drivers...