http://www.audiojunkies.com/blog/573

Omnidirection speakers seem a good thing in theory but in practice there are lots of accoustic problems associated them...

The off axis even spectrum output caused by a speaker with very wide off axis response is [1] beneficial for the perception of audio quality with stereo music reproduction, when properly utilized.

-Chris

Footnotes
[1]Loudspeakers and Rooms for Sound Reproduction—A Scientific Review
Floyd E. Toole
JAES, June, 2006, Vol. 54, No. 6, pages 451-476

I thought the point of good speakers is to have as small membrane as possible, so the sound source nears perfect needlepoint so the stereo spacing would be near perfection when sitting in that famous triangle with your speakers. These "omnidirection" speakers are good for lounge bars, aka "how to get the sound to as large space as possible without wasting too much money".

IMHO, of course, I haven't ABXed.

If you did have a needlepoint size sound source that worked, and there were no physical obstructions, it would, in fact, have omnipolar dispersion.

-Chris

I own a pair of speakers somewhat similar to these; the Ohm Speakers F-series, which cost my now-departed uncle around $4000 back in 1974 (and they're now in need of reconditioning). The 'omni-cone' type of driver is certainly not a new thing, and it sure does have its faults, but it can still make a fantastic speaker. A violin does not radiate to a needlepoint, nor does any other acoustic instrument, so I wouldn't say that a speaker should necessarily do so either. Radial dispersion creates a sort of 'space' that's interesting and appealing (at least to me).

Anyone who might ABX these types of speakers with more conventional cone diaphragm speakers is kind of missing the point. I can't say where my particular preference lies, but there's certainly something fascinating about the way a speaker like this can sound -- not better, necessarily, but interesting and different, certainly.

I have a pair of SoundLab Pristines I am very pleased with. I have stopped shopping for speakers.

The Ohm speakers(the old ones) have full range omnipolar dispersion, but have many other issues, such as resonant cabinet systems, non linear response(resonant transducers), and probably high non-linear distortion at moderately high volume levels. The newer Ohms speakers abandon the full range omnipolar design in favor of monopole tweeter systems, using the omnipolar driver only for the midrange band.

I would not consider Ohm to be a very good example of an omnipolar system. A good current example would be the higher end MBL speaker systems, which have reasonably linear, low resonance, full band omnipolar response. Of course, it should be noted that special precautions should be especially heeded in so far as room acoustics and placment with a true fullrange omnipolar system.

-Chris

Indeed so. My particular Ohms are still on the original drivers, and although I'm slowly allocating money into a refurb fund, I'm not particularly looking forward to it. As I said, the Ohms have their own set of problems, as you've described, but they're still interesting and completely usable speakers (in my opinion, anyway). As for distortion, they do exhibit some, but I haven't found it to be that annoying.


Perhaps not the best, but still an omni system, and they still demonstrate those qualities in what I would call an 'effective' way. They're not something I would have bought myself (probably not, anyway), but having inherited them, I've really been quite pleased with their capabilities.