Dipole thread for newbie

[jerusalem]

Many people seem to have claimed that once they have builded dipole speaker, they have not returned conventional box speakers anymore.Where does this difference come from, what are the strenght of dipole speaker against box speaker?

Greatly appreciated if someone would post experiences, link references about dipoles, how they work ,diy projects people have build and stuff like that.

Anything goes on what you think should help newbie to choose dipole project.That's all folks.

[Paul H]

There's a lot of stuff posted on this forum you can find with a search for "dipole". The most detailed wealth of knowledge on dipoles on the web is on Sigfried Linkwitz's site.

To me, the thing that has impressed me most about dipoles is the bass clarity. An electric bass guitar, or a cello, or a kick drum all play with distinctive tones rather than a 'muddy boom-boom' sound. I know of course that really good box speakers aren't muddy, but dipoles really excel in this area.

The significant downsides to dipoles are size and complexity. To get dipoles to play low requires multiple and/or large drivers, complex crossovers (or active adjustable crossovers with multiple amps) and a large baffle size. That's not to say that a dipole speaker can't be sized to fit in a good-sized living room (look at SL's Orion or jon's arvo) but if you're looking for bookshelf size don't look at dipoles.

Paul

[john k...]

To get dipoles to play low requires multiple and/or large drivers, complex crossovers (or active adjustable crossovers with multiple amps) and a large baffle size.

Paul

(JPK) Which is why a U-frame woofer system makes a lot of sense. Same quality bass as a dipole woofer, much more compact for the same SPL. 8)

[AJINFLA]

Jerusalem, just to be clear, when people say once living with a dipole makes it impossible to return to a box speaker, they are referring to an open baffle dipole. Those little rear surround boxes at Best Buy are dipoles also. Dipole refers to the radiation pattern only. Open Baffle implies dipole radiation, but also the most critical factor. NO BOX. There is a difference.

Which brings us to John's design, you have dipole to cardioid to dipole to monopole/dipole(tweeter) radiation pattern. Something I would rather avoid. May well sound very good, but...If the bass quality of the cardioid is the same as a (OB) dipole woofer, then why not transition to a cardioid midbass (Gradient) to keep the radiation pattern consistent. Does a cardioid midbass also have the same quality as an OB? Won't the power response of a cardioid (woofer) be closer to that of a monopole?
Why did you chose to go OB on your MTM section? Is it just radiation pattern that determines the SQ, or is there more to the "open" baffle dipole concept?
I think most who have gone the OB route know the answer there :W

cheers,

AJ

p.s. I'll eventually get around to a cardioid design, but it will be more like the Meyer or Nexo designs rather than a Nao/ME-Geithain U-frame.

[ThomasW]

(JPK) Which is why a U-frame woofer system makes a lot of sense. Same quality bass as a dipole woofer, much more compact for the same SPL

Different approaches require different sets of compromises. And a total noobie thread isn't the best place to rehash those discussions....

[AJINFLA]

Oh yeah, links for the noob. Well, a search of this very site itself should unearth a wealth of info about OB. The Arvo is just that.
And of course: The OB Bible - http://www.linkwitzlab.com/. Its huge, so take your time....
and for a simple, cheap project specifically: http://www.linkwitzlab.com/proto.htm#PMT1
John K's site: http://www.musicanddesign.com/
A search of DIYaudio.com should also give lots of projects, some as simple as a single driver (like the CSS125) on a piece of board. Might be an ideal OB starter project. I frown a bit on 4" cone tweeters myself.
Many more, but that should be where you at least start. Good luck.


cheers,

AJ

FYI, its true. Once you go the (competent design)OB route, there is no return to boxes unless absolutely necessary - which they can be.

[JonMarsh]

Which brings us to John's design, you have dipole to cardioid to dipole to monopole radiation pattern. Something I would rather avoid. May well sound very good, but...If the bass quality of the cardioid is the same as a (OB) dipole woofer, then why not transition to a cardioid midbass (Gradient) to keep the radiation pattern consistent. Does a cardioid midbass also have the same quality as an OB? Won't the power response of a cardioid (woofer) be closer to that of a monopole?
Why did you chose to go OB on your MTM section? Is it just radiation pattern that determines the SQ, or is there more to the "open" baffle dipole concept?
I think most who have gone the OB route know the answer there :W

cheers,

AJ

p.s. I'll eventually get around to a cardioid design, but it will be more like the Meyer or Nexo designs rather than a Nao/ME-Geithain U-frame.

While I only have a limited number of experiments to back up this belief, I don't think that mixing radiation patterns is a good idea for the most part.

I also have come to look on a cardiod woofer as an engineering tradeoff ( a valid one, of course, depending on the goals), and view it as a "transitory" alignment between full cardiod and monopole. As such, I think it's subjective characteristics in the room lie in between those points. Now, with the right size room and correct placement, monopoles can sound quite good, but it takes a lot of effort and space. I've only lived one place in my life where I could get them dialed in to my satisfaction; that was back in the 70's. In my limited experience, a full dipole can produce more realistic integration of the bass through midrange response in more room situations under less ideal circumstances, and without the degree of room treatment which may seem necessary for a monpole system. (Been there, done that, bought the movie rights in the 70's).

Without exception, at CES this year the most integrated lump free bass (gravy) was with systems using diople bass radiators. Within the limits of even the larger suites, it just wasn't possible to approach with a box speaker and any reasonable seating position. My hat's off to everyone who tried... but the proof is in the pudding.

~Jon

[Jack Gilvey]

To me, the thing that has impressed me most about dipoles is the bass clarity. An electric bass guitar, or a cello, or a kick drum all play with distinctive tones rather than a 'muddy boom-boom' sound. I know of course that really good box speakers aren't muddy, but dipoles really excel in this area.

Yeah, I think because you're hearing less of the room. I've found that dipole bass makes other subs sound much more like each other (be they vented, sealed, etc...) than like a dipole. And, to Jon's point, the "less ideal" the circumstance, the more true this is. In my cube of a room, it's not even close.

[john k...]

(JPK) With regard to the transition between different sources I think it is important to understand what is really going on and how different crossover choices affect the result. I prepared this study some time ago. http://www.musicanddesign.com/craw_cross.html

Of particular interest (at least to me) is the transition between dipole and cardioid using an LR4 crossover , shown to the upper left, (actually any order LR yields similar results). The transition is a smooth rolling of the dipole nulls to the rear.