Which speakers have wide dispersion?

Johnnyb53 hits most of the major points concerning omnis and dipoles. I would add that all speakers bring the room into the mix; omnis make it more obvious. In most ordinary rooms, all speakers do better with a little more 'breathing room' to reduce and delay first reflections.

This weekend I installed a pair of omnidirectional speakers in a loft style apartment—a very difficult room—brick and glass on two walls (front and right), drywall (rear and left), hardwood over concrete floor. Added to this is an asymmetry, wall to the right, open to the left. Fortunately, a high 14' ceiling of open wood joists. The room doesn't sound particularly live, but when playing full orchestra at a good volume, it overwhelmed and started sounding blocked up, although, all other genre sounded great. In this case, pulling the speakers out from the front wall hardly made a difference. Taking some measurements confirmed what I was hearing, so I compensated a little for the asymmetry by adjusting balance, and pulled back the mid & upper bass a couple dB. Still, that room needs more stuff here and there and on the walls for some absorption/diffusion to help tame the room.

All Vandersteens. The 5a is just sublime, when I have heard it there was not one certain sweet spot. Also, Klipcsh Khorns, really all good horns.

Drew, note that the SoundLabs espoused by Twb2 do not suffer from the narrowed radiation pattern one would normally expect from a large panel. This is because the diaphragm of the SoundLabs is a faceted curve, which radiates over a 90 degree arc (reduced to 45 degrees on some recent models to improve efficiency).

Interesting that you mention Earl Geddes - my own efforts owe a great deal to his work, though I don't think he approves of my bipolar variation.

Duke
dealer/manufacturer

Yeah, by today's standards the 1st-gen Mirage M series is a bit thick-sounding and not so transparent. To make them jump you need to pump them with lots of power with low output impedance, high damping factor, and high current. The 2nd-gen Mxsi series took a significant jump in transparency and clarity; they introduced Mirage's cloth-surround titanium tweeter and bi-wire/biamp capability. The new tweeter added a good dose of speed and airiness up top. The dual speaker terminals rewarded bi-wiring or bi-amping with improved top-to-bottom transparency.

But none of this compares to the entirely new levels of transparency, efficiency, detail, and realistic dispersion of the new OMD series. My brand new OMD-15s trump my old M5si's in every way, and are about 1/3 the mass and bulk.

And some (including professional reviewers) consider Mirage's new flagship OMD-28 to be a standard-setter at its price point ($7500/pair).

"Lifestyle" speakers? I don't think so.

You want uniform dispersion up to a few kilohertz with a gradual reduction in total power response at the high end.

While "omni" speakers are one way to achieve that, designs with controlled directivity (dipoles, wave guides) accomplish the same end-goal with fewer interactions with nearby surfaces and a preservation of detail and "correctness" farther into the room.

Planar speakers don't qualify as dipoles. While they have sound coming off the front and back-sides, they're acoustically large at high frequencies so they suffer lobing problems instead of having an acoustic dipole's nice off-axis behavior (off-axis response is -3dB down from on-axis at 45 degrees, -6dB at 60 degrees, and non-existant by the time you move out to 90 degrees).

I've built pairs of Linkwitz Orions (open baffle) and Plutos (they don't really start getting directive until 2-3KHz. and have no baffle outside the 2" mid-tweeter). The Orions have more reach into the room.

Some time I'll get around to trying a wave guide without the problems that go with horns - Earl Geddes work looks real interesting.

I lived with a pair of Mirage M-1's from 1988 (bought new) until 2002 and loved them for all the reasons well articulated by Johnnb53. I auditioned Martin Logan's in my space and found the beaming to be unacceptable. Sound Labs gave me everything I loved about the Mirages, and much much more. I recently had the opportunity to bring the Mirages out of storage and listen again, and they did not disappoint, although the SL's far surpass them. I am told the percentage of audiophiles who prefer the "planar" type sound vs. traditional box speakers is about 20%. You have to decide for yourself, but make sure you have experienced a well done "wide dispersion" system.

Johnnyb53,
Thank you for that nice description!

Which speakers have wide dispersion?
In one of the earlier threads reference was made to omni directional speakers sounding better due to the wide dispersion and that is the key to their signature.
Obviously this affects required room dimensions, is wide dispersion the way to go?

It depends on what is important to you. If you have a private, set-aside listening room where just you and a few companions can listen in a tightly defined sweet spot, then a narrow dispersion speaker or dipole flat panel (which takes the side boundaries out of the equation) would be desirable. Properly set up, this type of dispersion pattern lends itself best to the "palpable, 3D imaging" where the voides and instruments seem to hang spookily in 3D space. It's pretty difficult to achieve this type of 3D imaging with any other approach that I know of, but there are disadvantages: 1) It's totally picky about speaker placement, seating location, and room treatments to take room boundary reflections out of the equation 2) The sweet spot is narrow, and you often get a big drop in fidelity by standing up or moving more than a foot or two from the sweet spot; 3) It's not a very sociable setup; vocal and instrumental timbres will probably be off in one place or another (e.g., a "cupped hands" midrange) when listeners are too far out of the sweet spot.

Wide dispersion, esp. hemispherical or omnidirectional speakers tend to throw a wide, realistic (or sometimes over-sized, depending on the speaker and the room) soundstage, and eliminates or reduces many of the disadvantages mentioned in the previous approach. They make for a better "party speaker" or for listening when you are doing housework or otherwise can't sit in the sweet spot. Because omni's energize the room more like real instruments and voices, there is a truth to the timbres in just about any place in the living space. While placement is important, it is seldom as critical as the dipole flat panel speakers and the ones with limited dispersion with time-aligned drivers. The one disadvantage with the wide dispersion speakers that intentionally bring the room into the mix is that--while they often throw a realistic-sounding soundstage with an excellent sense of depth to this soundstage, they cannot achieve the "palpable 3D imaging" to the degree that you can achieve from the other approach.

For me, 12 years ago I was in the market for a new pair of speakers, and I was seriously considering the approx.$2K Martin-Logans, the Magnepan 2.7s, or the bipolar Mirage M5si's. Given that I had 2 dogs, 2 young children, and a family situation where getting to the sweet spot was going to be an exercise in frustration, I elected to go with the wide dispersion Mirages, and have never regretted it. You might say that the bipolar, omnipolar, and omnidirectional speakers have a more resilient soundstage. You get a stable soundstage and accompanying frequency response just about wherever you go in the listening area. Timbres sound true to life because the speakers interact with the room much like voices and instruments do. The only thing you give up is that last bit of pinpoint imaging, which I think is an artifice you seldom hear in live music anyway.

Although Pedrillo asked about 'wide dispersion' I think what he was, unknowingly (perhaps), looking for speakers which created a huge soundfield while retaining fidelity to the recording (pin point in the sweetspot/nearfield). Just a guess though. What he may not realize that there is no perfect speaker design, everything has built in compromises dependant on what the speaker designer is trying to accomplish.

Wouldn't it be nice if there was an overview regarding room design and speaker integration which described the design, the type of room set up required, and the probable results?

Some people have taken a good bite out of this issue (Duke, for example) but others, knowlegable though they might be, seem to just reinforce their personal experience/prejudice combined with what they have read which supports their opinions.

I'm too lazy and ignorant to do this, and wouldn't really know how to get it on the forum as a FAQ but IMHO it would be a great reference for many folks.

Pedrillo - wide dispersion is possible in a conventional speaker and it is also possible in an omni directional speaker (Beolab 5, Ohms, MBL)

However, contrary to popular belief - a large panel tends to have a narrow dispersion and suffer from lobbing - this tends to result in a smaller sweetspot. Of course the back wave from a panel creates an impressive ambience but this quite different from a point source with wide even dispersion. IMHO.

Because Omni's and most panels excite a backwave towards the wall behind the speaker they will be more restricted in terms of placement - however they will have a wide sweetpot.

Panels tend to have a smaller sweetspot beaming/lobbing and are also restricted in placement due to the backwave.

Originally I thought your thread was about wide dispersion - my initial comments refer to that. Wide dispersion gives a natural sound form a wide variety of positions.

Find out whether you like omni type speakers, cheaply. Parts Express has a close out of the xbox Spherex speakers. I have the original xbox spherex system and it is amazing. I think you can get a pair for $50.

Any Shahinian speakers, but Obelisks come to mind first and followed by Dhalquist Dq-10

Thanks for the mention, Shadorne!

At this point only one of my speakers would qualify as "wide dispersion", and that's my big Dream Makers, which are bipolar (kinda like their designer). But instead of the pattern being very wide primarily in the forward hemisphere, it's 90 degrees wide both front and back.

I chose this configuration because it's desirable to have as long a time delay as practical before the onset of the increased reverberant energy, and in most rooms the geometry works out to give a longer time delay if the extra energy is directed to the rear rather than to the sides.

As a longtime SoundLab owner and dealer, my observations echo those of Twb2. In fact, my bipolars deliberately seek to emulate the radiation pattern geometry that SoundLab designer Roger West used in the big A-1; that is, 90 degrees wide, both front and back. I received a Golden Ear award from Robert E. Greene for my bipolar, so maybe it works.

Duke
dealer/manufacturer

Having been a fan and owner of various types of planar speakers for over 45 years, I can wholeheartedly agree. Conventional dynamic (box) speakers are the opposite, with the sound coming from a point source, albeit when done well can present a wide and deep sound-stage. Nonetheless, you need to be in or at least near the sweet spot or there is a great drop off in many critical aspects of the sound. For the last many years I have become more and more enamored by the large Sound Lab electrostatics. With these, there is not a bad seat in the house. Even in the next room and beyond, it is as if you are near the presence of live music, with full timbre, body and presence. Because the entire panel is a full range membrane/driver of considerable size, all of the air in the room is excited and this carries on. My wife doesn't much like the audiophile "sweet seat" experience, but she loves being in the near presence of the great music. Granted, the imaging is generally best at one particular point, but every other seating position is entirely enjoyable. So my vote is not really omnidirectional, but electrostatic planars.

Even though there are some very fine cone based systems out there, I would have a hard time going back to traditional speakers.

Dali speakers too.

The Mirage Omnipolar and Omnisats have uniform room-filling dispersion, but with a forward-firing bias that improves imaging. The listening area is the sweet spot in the sense that if you are at a live performance sitting to the left of the stage, you still hear all the instruments and voices from the perspective where you're sitting. The Omniguide-based Mirages do the same thing. The center position is especially sweet, but the soundstage doesn't collapse when you sit outside the speaker pair. You still hear it as a soundstage.

I have a pair of Omnisat satellites and a pair of floor-standing OMD-15's. I also installed a sat/sub Omnisat-based system at my neighbor's living room. I've found that the Mirage speakers with the Omniguide mid/tweeter module are very easy to place for musically satisfying placement, but also reward more careful placement for better soundstage and imaging.

You will get good results even if you have to place the speakers close to the wall behind them, but you get better imaging and soundstage depth if you can bring them out 2-3 feet from the wall. The tonal balance assumes the "average" room with a mix of hard and soft surfaces, but you can definitely fine-tune the dispersion and treble energy by adjusting the ratio and locations of hard and soft surfaces.

I've gotten good results from both rectangular rooms with std. ceilings and open architecture living spaces with vaulted ceilings. Like I said, they're pretty accommodating of your listening area.

Speakers that follow this principle are many. Audiokinesis, Energy, Mirage, PSB, Merlin, Axiom, just to name a very few...it is the main reason that dome tweeters are so successful. It is one of the major challenges in a midrange - especially in a two way.

Many speakers do not - but to name them would cause unnecessary flames.

It sounds more natural - direct and reverbernat energy match. Sound is good in a much larger sweetspot. Sound is easy to listen too and relaxing as opposed to the headphone feeling you get with narrow dispersion speakers. You can enjoy the sound withouthaving to lock your head in a vice.