Which speakers have wide dispersion?

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.

Johnnyb53,
Thank you for that nice description!

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.

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.

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.