# Radial Speakers - why don't more people buy em?



## mamba315

Why aren't radial speakers more popular among audiophiles? They seem to have a lot of things going for them

 *Astounding imaging characteristics - every review mentions how holographic the imaging is, even in untreated rooms

 *High resolution - even Maggie-freaks seem to like these speakers, and don't think they lack resolution compared to the planar's

 *Wiiiiide (and deeeep) Soundstage - every review mentions this as well. Walk across the room and the stage stays in the same place. None of the "sweet spot" issues that plague many box speakers and planar panels. Sound seems to come from behind the back wall, and from beyond the side walls.

 *Awesome natural dynamics - "sounds like live music" is the common phrase

 Soundstage, imaging, resolution, and dynamics are some of the main criteria people use when evaluating speakers, and the radials seem to excel in all these areas. They seem to be a very affordable solution as well, given how well they pair with untreated or mildly treated rooms (the room is the biggest problem for speakers, generally speaking, IMO). The Ohm MicroWalsh model is around $1000, and with a good amp will put out enough bass to make most forgo a subwoofer. The Decware ERR is $1600, will play even lower, and features a very efficient design (93db/W). I've yet to see a bad review of either.

 It doesn't seem like radial speakers lack anything, yet they're not as popular as planars or horns, not to mention box speakers. Yet they've been around for a good 30 years. Any ideas?


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## DaveBSC

Quote:


  Originally Posted by *mamba315* /img/forum/go_quote.gif 
_Why aren't radial speakers more popular among audiophiles? They seem to have a lot of things going for them_

 

There just aren't that many of them out there. A lot of it may just have to do with them being "non-traditional". Audiophiles can be an obstinate bunch. Take the classic M-T-M center channel, for example. It's bad design and speaker builders know it, but they have to do them anyway because that's what buyers want. 

 It may also just come down to preference. Omni-radiators do a lot of things well, and because room reflections work with them rather than against them, they do need less treatment than other speaker types, particularly di-poles. The Germans build omnis better than anyone else, but even the best Duevel, or German Physicks, or MBL can't beat everything else in all areas. The best point-source, line-source, and di-pole designs (dynamic, planar, or electrostatic) have their own particular strengths.


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## Drag0n

Never heard of them, and i dont think any of my local audio store have them so i can give them a listen. I wont buy them if i cant hear them.


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## Barry

Well, I have a pair of shahinian obelisks, which I believe qualifies as a radial speaker and I love them. More realistic and less hi fi than many more traditional speakers. I have not heard Ohm speakers in a zillion years, but liked them back in the day.

 There are just not too many examples out in stores. Maggies are not quite the same, but the backwave does extend the realism of the music, compared to live, especially for acoustically generated music.


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## weibby

The sound presentation is something that is unnatural but some people like it some people don't.

 Even with 5.1 SACD, people don't really like the presentation from traditional speakers.


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## mamba315

Quote:


  Originally Posted by *weibby* /img/forum/go_quote.gif 
_The sound presentation is something that is unnatural but some people like it some people don't._

 

Are you saying this about radial speakers or traditional speakers?


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## DaveBSC

Quote:


  Originally Posted by *Drag0n* /img/forum/go_quote.gif 
_Never heard of them, and i dont think any of my local audio store have them so i can give them a listen. I wont buy them if i cant hear them._

 

The MBL Radialstrahlers are probably the best omnis built. It's worth finding a dealer or going to something like RMAF to hear what the 101s can do.


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## Uncle Erik

They're interesting, but I intend to stick with the Quads and Orions.


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## IPodPJ

Quote:


  Originally Posted by *mamba315* /img/forum/go_quote.gif 
_Why aren't radial speakers more popular among audiophiles? They seem to have a lot of things going for them

 *Astounding imaging characteristics - every review mentions how holographic the imaging is, even in untreated rooms_

 

If you think about it, it would make sense for more speakers to be of a radial configuration. A microphone receives sound from 360º, therefore a speaker should too. The downsides are that reflections can come from all over the room, and the sound isn't primarily directed at your ears. So it's a toss-up. I wish I had the money to buy a pair though.


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## krmathis

Let me guess...
 * Few available makers/models.
 * Low availability (few stores carry them).
 * Price point.


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## anetode

Completely agree, the market for omnis should be much bigger than it is. Their technology is just so clearly superior to front radiators that require a sweet spot for even response. I wish there were more options than the aesthetically-challenged Walshs and the uberpriced MBLs, though I still lust for the latter.

 One factor I haven't seen compared is harmonic distortion - this is where omnis might lag behind traditional speakers. Speaker driver manufacturers are getting pretty good at approaching the ideal of pure pistonic motion and I imagine that controlling unwanted vibrations would be more of a challenge in omni diaphragms.


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## anetode

Quote:


  Originally Posted by *weibby* /img/forum/go_quote.gif 
_The sound presentation is something that is unnatural but some people like it some people don't.

 Even with 5.1 SACD, people don't really like the presentation from traditional speakers._

 

People aren't used to diffuse sound fields and concert-hall levels of reverberation. The artificial closed-in but tightly focused imaging of stereo direct radiating speakers has supplanted the immersion of live events as the ideal reproduction. Acoustics researchers like Floyd Toole have argued that greater acceptance of multichannel audio and unorthodox speaker design will eventually overcome the antiquated stereo paradigm of hi-fi.


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## JB197

The only time I have heard that type is at a show and frankly it wasn't very good. Perhaps if more were available? But then again, the world is already flooded with speakers of one type or another. Perhaps aesthetics is also an issue, because the ones I saw were rather ugly and I can imagine many not wanting them in their domestic living space. 

 I'm not sure I agree with Floyd Toole about multichannel audio because most people that I know really don't want 5 speakers in their living room let alone 7 or more. 

 Perhaps radial will progress in time, but I'll be sticking with my cans for now!


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## Uncle Erik

What's so wrong with a sweet spot? Concert halls have some seats that sound better than others. Further, I usually listen in one position, so it's not inconvenient. If I'm moving around the room, that's almost always because my attention is on something other than the music.

 Also, omnis use several different types of transducers. I haven't looked much at the MBLs, but they appear to be some kind of hybrid ribbon/planar. I've seen others that use dynamic drivers. An omni is a radiation pattern, not a different type of driver. You can configure a planar to be single ended, dipole or omni, depending on how you employ it.

 Like I said, I'll stick with the Quads and Orions. For me, an omni is a solution to a problem I don't have.


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## anetode

MBLs use electrodynamic drivers with a conventional voice coil at the base, but radically different diaphragms vertically arranged like petals around the coil & magnet structure, flexed by tension from the top end. Ohm Walsh and German Physiks use a wholly different principle in their transmission line drivers (& offer a great writeup @ http://www.german-physiks.com/images...nology_web.pdf) Yet other omnis are traditional drivers whose output is dispersed by an acoustic lens, like Mirage or B&O Beolab 5s.

 The ideal driver would mimic the dynamic patterns of dispersal unique to each instrument, but this can't be realized. Omnis are the next best thing, whether in stereo or discrete surround layouts. Although a convincing effect can be achieved with a mix of direct radiators and dipoles in a 5+ speaker arrangement, this still limits you to a specific spot in the room. That's fine for solo listening, but with family or guests or doing various activities around the room, there are benefits to going with the omni approach.

 Then again, some prefer tight & focused stereo over a diffuse and enveloping soundscape.


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## JaZZ

I've always had an interest in radial speakers / simulated point sources. And I have experimented quite a bit with own designs. In my book the main goal of a radial speaker is to avoid the irregular radiation characteristic within the frequency band (particularly an increasing directionality toward high frequencies) and replace it with a spheric radiation. Any other regular, frequency-neutral radiation characteristic would be utopistic. But a true spheric radiation is almost impossible as well – it would require a true point source or at least a spheric membrane responsible for all frequencies, or at least from 500 Hz upward. There have been attempts in this direction. Siegfried Klein's magneto-restrictive sheet sphere comes to mind. But sonically apparently it wasn't really satisfying (so I guess – hard to imagine how massive resonances can be avoided in such a design). Since the treble is the most affected area, it may suffice to use a plasma tweeter in co-operation with a dome squawker to achieve a passable approach to the point-source goal. And indeed the prototype of a plasma tweeter on top of a conventional speaker was the best implementation of a point source I've heard so far. Unfortunately the prototype never was produced in series – without any shielding against the emitted radio waves it wouldn't have been legal, and with a massive shielding (à la Magnat) the sound would have suffered too much.

 Well, the natural radiation of acoustic instruments is neither purely directional nor purely spherical – each instrument has an individual radiation pattern. Horn instruments have the narrowest radiation angle, at least at middle and higher frequencies. Triangles, cymbals, violins... have a rather wide dispersion even at higher frequencies, but radiation is still not exactly spheric. So a music reproduction through a perfect point source wouldn't exactly sound like the real thing, but in fact slightly too diffuse – and too uniform with respect to the different instrument characteristics. Nevertheless it would provide the closest impression to a live concert, provided that the room acoustics are adequate, i.e. rather on the dry side. But again: The radiation patterns of conventional «direct-radiating» speakers represent a rather unnatural dispersion, with lots of irregularities and most notably an increase of directionality toward high frequencies, whereas lower frequencies are allowed to radiate almost spherically.

 Speaking of room acoustics: Normal living rooms, even if passably prepared for music listening, are a bad precondition for a lifelike reproduction of a large orchestra. The reverberation delay is much too short, there will always be the impression of a small room. Of course it helps that the recording already contains the large acoustics of a large concert hall, but reproducing the latter in a small room means adding inadequate, artificial reverberation to the original reverberation, i.e. reproducing concert-hall acoustics within living-room acoustics. Hence the increased reverberation produced by «omnidirectional» speakers – although actually providing a more even radiation characteristic – will naturally increase the «fake» effect. Therefore a countermeasure in the form of careful room treatment is indispensable to avoid a too diffuse sound experience. Apart from this problem «omnidirectionality» in fact leads to higher realism, simply because it implies a less frequency-dependent radiation characteristic. This makes for a relatively neutral indirect sound from all directions – necessary for a realistic reproduction of a concert-hall experience.

 During my own radiation experiments I used acoustically «hidden» indirect radiators for the recreation of the missing higher frequencies within the reflected sound, I also used diffusors on top of conventional drivers, particularly dome tweeters, but also dynamic horn, piezo and ribbon tweeters. One of the latter designs with a Decca Kelly ribbon driver with a large horn and a special diffusor on top of it for 180° radiation provided a particularly realistic sound, so much so that a female friend of mine couldn't stand it. However, it was exactly the latter configuration which revealed a fundamental weakness in the reflector method: a certain hollowness and indirectness, the same effect that's also present in horn speakers, just to a lesser extent. Apparently the reflections within the reflector arrays (and the horns) leave their traces. At least smaller reflectors with smaller tweeters behave much less conspicuously in this respect, so they're a practicable compromise. The best results concerning this matter was provided by a piezo tweeter whose horn was shortened to a few millimeters, so it is virtually reduced to the compression chamber and some phase-correction channels. The small conical diffusor on top of it (which halfways recreates the horn function) is acoustically very inconspicuous.








 A quite attractive commercial solution is Elac's 360° ribbon driver. 









 Unfortunately it can only be used at rather high frequencies without harmonic distortion getting out of hand – certainly the poor suspension plays a role here.

 My own implementation of a 360° ribbon driver (only existing on paper) introduces an ultra-thin nylon or kevlar yarn (red) as super-elastic suspension. The downside is a complex form of the pole pieces which would be expensive to manufacture. In contrast to many other tweeter designs it also offers excellent ventilation enabling a large air volume and thus low resonance frequency and low inner reflections.







 I haven't heard a fully convincing buyable 360° radiator so far. I've heard the walsh driver, but was rather unimpressed, so much so that I even can't remember the sound. I have heard the Magnat Plasma system...






 ...and there the three (or so) metal grids necessary for radio-wave suppression killed the sound. I haven't heard the MBL Radialstrahler...









 ...but expect them to be somewhat handicapped in terms of transient response due to the complicated drive principle and moreover the partial-vibrator design calling for resonance damping. I friend of mine called the sound «slightly artificial» (it was a different type than illustrated, though).

 The most promising approach in my view (and substantiated by some imperfect prototypes) would be direct radiating 360° drivers of a rather simple and conventional principle: vertically radiating «dome» tweeters and squawkers with sort of a slightly curved cone in the form of a candle flame:






 Unfortunately I'm not into speakers anymore. But if someone likes to get inspired by my ideas, more power to him/her! 
.


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## JEF1978

Very late answer but maybe you are still wondering why these speakers are not so common.
 In 2012 I had the same question, why are there so little radials. If you read the reviews these speakers must be very good.
 So I began to develop my own special driver (special for radial setup) Looks almost the same like the Decware Err driver but only the outside.
 I don't use a spider so the cone is directly attached to the former, not with a long needle like the decware. Also don't use a surround and the suspension is electromagnetic.
 The whole cone is held radial in place with ferrofluid. In these terms this is theoratical a perfect driver. Like the Decware the tweeter is on top of the midbass driver.
 That said now the sound...
  
 Radials do have some benefits but also has its dawbacks. There are some articles where is said that the reflection works with the radials and not against them like normal speakers do.
 In this mather I don't completely agree, Reflection is not good it give some specious effect and in the beginning it has some WAW factor but after a while it tends to be fatiguing. There is some lack of detail and smoothness. But there are also some advantages, like offcenter frequency response and a larger sweet spot. You have to pay attention to place the speaker in the room, because, if you place the speakers to narrow to a wall (left or right) the sweet spot is totally messed up (also a small room will give problems) because of these reflections. If you look on youtube the radials are mostly placed in center of the room. But who can place his speakers in center of the room? There is some solution to this problem, tilt the speaker 5-10degree forward and the soundstage will improve alot. (more direct sound) also avoid walls on the side. A wall at the back is no problem. In this setup you got the best of radial and traditional speaker setup.
 Also I thought in the beginning that the soundfield of a radial is spread over the whole backwall (i am talking for a hybrid like the decware) but I have to dissapoint you it isn't. It is a little bit larger but not super great unless you put the speakers far from each other. Again I speak for the hybrids not the full radials.
  
 Bottom line,
 Radials are good speakers but placed on 0° against some walls (uneven) the soundfield is messed up, a traditional speaker is a better choice.
 But...
 If designed well with good balance of direct and radiated soundwaves these can be astonisching speakers with very clean, open sound and good soundstage.
  
 further:
 Decware don't uses a crossover for the midbass driver, but the driver goes completely in his break-up region (oke it is mostly radiated to the ceiling but it is audible) 
 I know this is done for better dispertion of the high freq. I also played alot in these setup, give more open sound. But after awhile it began to irritating (High distortion) difficult to adress by ear but you hear that there isn't something right.
  
  
 Regards from Belgium


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