what is a dipolar speaker?

Question

i need to know WHAT a dipolar speaker is. what a bipolar speaker is. a vented box speaker? a sealed box speaker?

Answer 1

A Dipolar speaker has speaker cones on the front and back of the box out-of-phase with each other, while the drivers are one side are pushing, the opposite side is pulling. The result is there is a "null" or a dead zone of sound on the center axis of the speaker. When properly set up, a pair of dipole speakers used as surround speakers will provide a very open, enveloping rear effects soundstage without allowing you to pinpoint the location of the speakers. But for all this to work properly, the speakers need to be positioned exactly to the side of the listeners. If you are sitting out of the null area, the effect is ruined.

A Bipolar speaker has speakers on the front and back of the box in-phase with one another - both sides push air at the same time. The result is greater sound output where the dipolar speaker's null would be. Theoretically, a bipolar speaker approaches a 360° sound field - it squirts sound all around the room. That's a good thing if you need to position your surround speakers behind your listening position or anywhere outside of the null / side area.

A Vented (ported) speaker has a hole in the enclosure. Ported speakers are more efficient with higher distortion than sealed speakers. Ported speakers aren’t as accurate as sealed enclosure speakers.

You can see where this is going.

A sealed box speaker has no holes. Sealed speakers are less efficient (require more amplification) yet are more accurate than ported speakers.

My favorite speakers are panels (Martin Logan / Magnepan) and don’t follow any of these “rules”. Panel speakers are bipolar with no holes. They are very inefficient with incredible sound.

Your question would have had more value if it included the speaker under consideration.

If you haven’t purchased speakers yet - strongly suggest looking at panel speakers. You can’t power them with a receiver – but the added expense of a preamp and amplification with panel speakers is magical.