Why are OMNI speakers not more popular?

[graaf]

flooder-like polydirectional speakers from Denmark:

An externally hosted image should be here but it was not working when we last tested it.

 

[critofur]

The idea is that in any of it's current iterations, it's terrible. I agree that if it was possible to do it properly, it would be great, much like how using 6 video projectors to turn every surface in your room would be great for movies, if there was source material to go along with it.

If you used 6 projectors to turn your room into a giant video of a fishtank I'm sure it would impress the neighbors, but would you watch a movie on it?

I'd love for there to be a way to get omnidirectional sound from source to speaker, but what we're talking about here is taking polar, or at the very best bi/dipolar recorded soundwaves and fire hose spraying it incoherently around in all directions.

Well... I listened to "Holographic" recordings (stereo done with mics on either side of a sphere) playing back on quasi-omni speakers (stero pair, in front of me) and I heard footsteps CLEARLY coming from BEHIND me - it was freakish and made me feel like I was in the space where the sound was recorded, rather than listening to music being played back in MY room...

Not saying that the above setup does not have flaws, but, it sure can be cool on some recordings (including live jazz recorded at a club).

 

[Flaesh]

Atlas Sound beautiful green omni:
Atlas Sound ATS183GS 70V Short Base Garden Speaker ATS183GS B&H

 

[dantheman]

These examples mirror some playing around I'm doing with room synthesis programs in an AV receiver. That is, that what you hear is so dependent on the program source.

With your acoustic guitar every new transient is heard both left and right for many of the cases. As the chord sustains it is all recedes to the left channel. Only the initial transients get the benefit of the reflection. On the electric guitar with high fuzz, I never hear it in the right channel, their aren't any high transients to reveal the echo.

Griesinger of Lexicon talks about this a lot. They use a term called "running reverberation" and talk about the music needing quick decays and quiet spots between chords for reverb to be revealed.

I notice the same with the DSP echo. You can add a fair amount to music and set it to a level where it is fairly subtle, just detectable, and then switch the source over to talk radio and the amount of echo is laughable. Voice reveals it, fairly continuous music almost hides it.

So does that mean that an omni speaker may be perfectly fine for some types of music?

David S.

They probably are, but I personally have a huge collection of music that digs into many genres and my recording have all sorts of effects and things buried in them. Not sure I'd want to muck with it too much.

Dan

 

[UnixMan]

An extremely cheap and easy way to try out yourself what a good omni can do...

PERIAKUSMA: the construction

See also: Omni-Directional Speakers "Periakusma" (AKA Walkaround)

 

[el`Ol]

Thread topic obsolete.
The majority of bluetooth loudspeakers seems to be omni/flooder now.
https://www.google.de/search?q=blue...zBswb_qYDQDA&ved=0CAcQ_AUoAQ&biw=1280&bih=848

 

[Juhazi]

Omni like any other type of acoustic radiator/transducer system works in and with a room (if in a room) Reflections of sound and room reverberations and modes are very important as we know. Omnis create more reflections than any other type, and changing their position modifies reflections a lot.

Speech intelligibility is very critical to these phenomena. Any speaker's STI (Speech Transmisson Index) in a room and such characterics can be measured. STI is proved to have good validity with intelligibility perceived by humans. However this is a very complex field, more info here Mc Squared System Design Group, Inc. - Design for Speech Intelligibility

About STI Speech transmission index - Wikipedia, the free encyclopedia

A high STI is good for speech, not necessarily good for reproducing music.
Perception of sound is a popular field in science - psychoacoustics Psychoacoustics - Wikipedia, the free encyclopedia

 

[Barleywater]

Thread topic obsolete.
The majority of bluetooth loudspeakers seems to be omni/flooder now.
https://www.google.de/search?q=blue...zBswb_qYDQDA&ved=0CAcQ_AUoAQ&biw=1280&bih=848

Most of these are terrible approximations of true omnidirectional speakers, beaming higher frequencies at ceiling.

With more truly omnidirectional speaker, uniform directivity insures that spectral balance of all reflections is even, which is much more natural listening condition.

When instruments with highly omnidirectional radiation are played live in moderate sized rooms, nobody complains about the sound.

With highly uniform spectrum of reflections relative to direct sound, perceptual mechanism effectively and quickly associates reflected sound with direct sound, allowing more relaxed concentration on direct sound. With truly omnidirectional speakers, bulk of reflections are effectively ignored.

Moving omnidirectional speaker about room changes direction of reflections from listener perspective, but does not change spectral balance of reflections. This is not the case with typical box speakers and dipole speakers.

In Linkwitz Orion beaten by Behringer thread, test was about audio scene rendering; both speakers were beaten out by simple speaker with drivers on multiple faces of enclosure.

 

[markus76]

With highly uniform spectrum of reflections relative to direct sound, perceptual mechanism effectively and quickly associates reflected sound with direct sound, allowing more relaxed concentration on direct sound. With truly omnidirectional speakers, bulk of reflections are effectively ignored.

So why was the dipole in the Harman tests not preferred over boxed speakers? The spectral balance of reflections should be closer to the direct sound compared to boxed speakers.

In Linkwitz Orion beaten by Behringer thread, test was about audio scene rendering; both speakers were beaten out by simple speaker with drivers on multiple faces of enclosure.

Or maybe it was just the increase in spaciousness that was preferred?

 

[Barleywater]

All differences of preference in limited testing discussed in thread I referenced were marginal.

In referenced thread box speaker did beat dipole.

I have not mined through wretched thread; did tested Orion have rear tweeter?



What was statistical significance in Harman tests? What were these test looking to compare? Got a good link to Harman testing?

Spectral balance of dipoles is likely not so good. Radiation from backside of most drivers is poor imitation of front side; this leads to significant unbalanced spectral content in speaker baffle plane too. LX521 has rear tweeter, but this is not effective in 500Hz-5kHz range son critical to timbrel perception and directional/spacial cue presentation.

I'm not a fan of dipoles; I believe they are big waste of good driver excursion, making even spectacular drivers produce audible degradation from intermodulation distortion.

When Linkwitz made Pluto he was stunned at general similarities in perceptual performance to Orion. Rather than fully explore Pluto, he sought to elevate Orion back to its "rightful place". Many modification later he arrived at LX521, a real waste of good driver excursion.

Linkwitz completely skipped possibility of Pluto with rear facing tweeter.

Be it imaging clarity or spaciousness, original Orion did not excel in referenced testing against Behringer or IMP.

 

[6.283]

Linkwitz completely skipped possibility of Pluto with rear facing tweeter.

Rightfully so. A rear facing tweeter is a misconception for Pluto. It does not work and what should it do anyway ?
If you want even wider dispersion you need a smaller tweeter like the one I have used.

 

[Barleywater]

Rightfully so. A rear facing tweeter is a misconception for Pluto. It does not work and what should it do anyway ?
If you want even wider dispersion you need a smaller tweeter like the one I have used.

If you really want even wider dispersion, much higher power handling, and much lower distortion skip the smaller tweeter, you need a design like the one I have used:

 

[c2cthomas]

If you really want even wider dispersion, much higher power handling, and much lower distortion skip the smaller tweeter, you need a design like the one I have used:

Ahhhhh - another fan of the Sonotube!!!

 

[OllBoll]

If you really want even wider dispersion, much higher power handling, and much lower distortion skip the smaller tweeter, you need a design like the one I have used:

If you haven't finished the speaker and if there is room an idea is that you raise the distance to the middle somewhat such that you can invert one of the bass drivers to reduce distortion.

 

[craigj]

Or, a few prototypes based on Aleksandar Radisavljević's designs;






Cj

 

[graaf]

Most of these are terrible approximations of true omnidirectional speakers, beaming higher frequencies at ceiling.

With more truly omnidirectional speaker, uniform directivity insures that spectral balance of all reflections is even, which is much more natural listening condition.
...
In Linkwitz Orion beaten by Behringer thread, test was about audio scene rendering; both speakers were beaten out by simple speaker with drivers on multiple faces of enclosure.

those terrible approximations are not omni, IMP is not omni, because an omni is not really the thing, the thing is a certain pattern of early reflections

 

[Barleywater]

those terrible approximations are not omni, IMP is not omni, because an omni is not really the thing, the thing is a certain pattern of early reflections

Graaf;

Your "floor coupled ceiling firing" speakers are crude entry point into realm of omnidirectional sound. They all suffer from very limited output capabilities, and listener is hearing sound dominated by room. Been there, done that experiment. With your setups, wall reflections are poor spectral representations of direct sound.

You ceased exploration beyond first baby steps.

IMP is better approximation of omnidirectional sound in horizontal plane than any ceiling firing design.

There is no certain pattern of early reflections, only real pattern dependent upon speaker, speaker radiation pattern, and speaker's relative location to reflective boundaries.

 

[graaf]

IMP is better approximation of omnidirectional sound in horizontal plane than any ceiling firing design.

I beg to differ.

But anyway - nobody needs an omni really. An omni dispersion is not a goal in itself. And the idea of FCUFS is not about having "an approximation of an omni".

There is no certain pattern of early reflections, only real pattern dependent upon speaker, speaker radiation pattern, and speaker's relative location to reflective boundaries.

You clearly don't understand my point. Ok, anyway, no problem, let's blame it on my poor English command.

Take it easy. There is no need to get emotional really

 

[graaf]

If you really want even wider dispersion, much higher power handling, and much lower distortion skip the smaller tweeter, you need a design like the one I have used:

Cool looking for certain

However I would like to see some horizontal polar graphs of this "better approximation of omnidirectional sound in horizontal plane"

 

[graaf]

IMP is better approximation of omnidirectional sound in horizontal plane than any ceiling firing design.

the descrioption of Eickmer speakers

“Improvement” to Bose 901s—according to Gary
–Four Radio Shack in-wall speakers, one on each face of cabinet
–Pair firing back towards front wall, full level
–Inward facing, 6 dB attenuated
–Outward facing, 12 dB attenuated

"a better approximation of an omni in the horizontal plane"?

Oh I see! Now I get it! You're kidding, right? A really good joke then! Thanks fo a healthy laugh!