# Dipole/Bipole



## Guest (Jan 2, 2007)

I'm planing on using my HT as a mixed mdeia room -HTFR. I've read some things on using Dipole and/or Bipole speakers in the mix. Any suggestions?


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## Guest (Jan 3, 2007)

You didn’t really state your budget and I am not sure how large of a design you are looking for… but as far as cheap full range speaker design go this http://homepage.mac.com/tlinespeakers/FAL/downloads/BipolarMLTLDesignPak.pdf has to be one of the best values out there . I built these a year ago for a friend who used them for his front left and right speakers. Later he upgraded his front end and now they serve as surround speakers. Don’t be fooled by the size of the driver, it really can play to 40hz! Total cost for the pair was under $300.


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## Sonnie (Apr 11, 2006)

I think we musta missed the HTFR acronym when we prepared the Glossary... what does that stand for?

It is my understanding that Dipole speakers should only be used for surrounds. Bipole OTOH, can be used for mains or surrounds and have better response. 

Did you have an idea in mind or just starting from scratch?


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## Guest (Jan 3, 2007)

I am planning on going with an in-wall becuase of space limitations. The Dipole/Bipole question is for a basic understanding. I plan on listening to multi-channel recordings, but the primary use will be for movies. I understand that the front channels should be mono-pole speakers and the rears would be better as either bi or dipoles.

HTFR - Home Theater, Family Room. I saw it in a couple of threads. Next time i'll just refer to multi media room
Thanks


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## Otto (May 18, 2006)

DCtheDC said:


> I am planning on going with an in-wall becuase of space limitations. The Dipole/Bipole question is for a basic understanding. I plan on listening to multi-channel recordings, but the primary use will be for movies. I understand that the front channels should be mono-pole speakers and the rears would be better as either bi or dipoles.


Hi there,

If you're thinking of going with in-walls, then bipolar/dipolar is out, I think. The -polar speakers kind of imply a "front" and a "back" to the speaker. If you're going in-walls for fronts, you can certainly still use bi or dipoles in rear. An in-wall really only has one "side" to it, so there's no opportunity for differing phases. I guess they could phase different speakers on the in-wall differently, but I don't think it would sound very good -- lots of weird cancellations.

So, first, the definitions.

A bipolar speaker has two poles which are in phase, but on different sides of the cabinet. Thus, both front and back speakers move "out" with a positive pulse and vice versa. This is the design that Definitive Technology uses.

A dipolar speaker has two poles or sides that are _out_ of phase. Thus, when the front moves "out", the back moves "in" -- the back and the front move in the same absolute direction. Think of a Martin Logan electrostatic panel -- the front side of it moves forward and the back side moves "backward" due to its open baffle design. 

So, either can be used for a main speaker, as well as for a rear speaker. DT makes the bipolar fronts and rears (I believe their fronts are all single-baffle, front firing speakers). I believe Paradigm has some _di_polar rears. I'm not exactly sure on the design of the ML center and rears, if they are truly dipolar or not. I think that Magnepan uses the same technology as its dipolar magneplanar speakers for centers and rears. I'm sure there are other manufacturers out there making these types of designs

So there are all kinds of choices when it comes to design types. I had a 5 channel Definitive Tech system for a year and a half. I like the bipolar fronts for movies, but not as much for music. I still have the rears in place with a different front-side setup, and I've always liked them for rear effects. I'm going to switch to monopole rears that match my mains, so we'll see how I like those.

Now, as to which to choose, it's up to you. To me, the bipolar rears give a good sense of spatiality. So do the bipolar mains with movies. If you are into listening to music, you might find that the DT bipolar sound doesn't have the greatest imaging. I have convinced myself that they sound "pretty good", but they were never good enough for me with music. As to dipoles -- I used to have Magnepan MMGs. I liked them as speakers. Not dynamic enough, but I think I just needed their bigger brothers. They had a great air about them for music. I never used them much with movies. I also recently listened to some Martin Logans, and they sounded good (but overpriced for their sound) on movies and music. I thought they had a pretty tight sweet spot and were beamy. On movies, that's reduced and they gave the clips I watched a good ambiance.

Hmmm... Well, that's a start! Good luck!


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