Omnidirectional speakers

[tmuikku]

Hi, I think the party effect is just due to ~constant directivity. High DI ~constant directivity speakers can sound the same anywhere in the room as well depending the toe-in. Basically the whole room is the listening area. Difference between high and low DI is that with high DI phantom center stays between speakers with bigger listening area because time / intensity trading can be used, without time intensity trading the phantom center collapses to nearest speaker quite fast. Both could sound roughly the same timbrally anywhere in the room.

It's bit of a nitpicking? just a point of view that the property that makes big listening area is not only omni, but just smooth flattish DI, perhaps nature of edge diffraction also affects the perception, which makes sound that changes per direction, omni speaker with drivers ponting up have this kind of diffraction stuff mostly toward ceiling.

I very much agree I've found smooth sound through out the room to be very important thing to have with a loudspeaker system, especially at home where I move around a lot with music playing. The sound that doesn't change (seemingly) regarles of listening position is great, calming, opposite to some other speakers I've had which don't seem to have any single sound as the sound changes all the time as head moves. I have cardioidish system now and bet I'd be fine with nice omni or dipole as well in this sense, why not anything that has nice DI.

 

[jim1274]

Hi, I think the party effect is just due to ~constant directivity. High DI ~constant directivity speakers can sound the same anywhere in the room as well depending the toe-in. Basically the whole room is the listening area. Difference between high and low DI is that with high DI phantom center stays between speakers with bigger listening area because time / intensity trading can be used, without time intensity trading the phantom center collapses to nearest speaker quite fast. Both could sound roughly the same timbrally anywhere in the room.

What about behind the speakers, looking at their back while listening?

It's bit of a nitpicking? just a point of view that the property that makes big listening area is not only omni, but just smooth flattish DI, perhaps nature of edge diffraction also affects the perception, which makes sound that changes per direction, omni speaker with drivers ponting up have this kind of diffraction stuff mostly toward ceiling.

I very much agree I've found smooth sound through out the room to be very important thing to have with a loudspeaker system, especially at home where I move around a lot with music playing. The sound that doesn't change (seemingly) regarles of listening position is great, calming, opposite to some other speakers I've had which don't seem to have any single sound as the sound changes all the time as head moves. I have cardioidish system now and bet I'd be fine with nice omni or dipole as well in this sense, why not anything that has nice DI.

I can see what you might be getting at with listening positions well off axis of the central position, but can’t see how any DI index could do what you describe once you get directly to the side (and moving further to behind the forward radiation) by 90 degrees or more off axis.

 

[tmuikku]

Well, in such cases where party is on the back, then I'd guess omni speaker would be best as it is perhaps closer to ideal pattern than a dipole or cardioidish speaker would. For example, drivers off an OB system have some anomalies in response behind due to baskets and magnets and other structure being there, but not in front. If these were ideal, then it wouldn't matter: although direct sound would have lower SPL behind speakers the timbre would be roughly the same, direct sound is just attenuated but has same frequency response as any axis. In reality, most of the room hears roughly the power response, so, not too much difference as long as DI is nice which means power and direct sound are pretty similar no matter which direction one is at. Ideally at least.

Stereo phantom center collapses with any speakers if you get too far off-axis, but for example 3 person sofa can have stable phantom center for all three people with time intensity trading. Basically the time intensity trading stabilizes the image, vs. unstable without: If listener moves from MLP to either side, it gets closer to the same side speaker and further from the other, which makes the closest speaker dominate the other as it's sound arrives first and is louder (no toe-in), while the other gets quieter and further away magnifying effect in a way and phantom center collapses to the closest speaker. With directional speaker and suitable toe-in one is now more off-axis the closer speaker so it attenuates instead, while more on-axis the further one which now increases in level, and these compensate for the time delay stabilizing the image, keeping the phantom center between speakers. It's still not rock solid, but still quite stable feel to it.

This is very easy to listen, sitting at main listening position start moving your head to either side, eyes closed: on unstable situation the singer panned in the middle speeds up towards closest speaker much faster than your head moves, localization of center changes quite a lot. On stable situation the singer kind of tries to stay on the center. Basically the localization is more stable and difference in reality is the latter system feels more solid, more calm in a way as we naturally move some all the time.

See these for example

Time intensity trading | Auditory Neuroscience

auditoryneuroscience.com

http://www.gedlee.com/Papers/directivity.pdf

 

[Justdafactsmaam]

Omnis will fully engage the room. If you like the sound of your listening room I guess it’s a good thing? I don’t want to hear my listening room.

 

[xschop]

That’s an interesting thought, but see two challenges:

1. Getting them far enough away from the wall behind them (front wall) to reduce/delay early reflections

2. Finding a suitable desktop size omni speaker.

There are not many desktop Omnis that I’m aware of—have these myself:

360 PEAK Music System By Level10 – soundmatters

soundmatters.com

Harman Kardon Aura Studio 4 | Bluetooth home speaker

Brilliant visuals. Beautiful Harman Kardon sound. Set your musical mood with the transparent dome and themed lighting of the Aura Studio 4 Bluetooth speaker.

www.harmankardon.com

These are designed to be stereo from one unit, so suspect you were thinking seperate L & R Omnis?

Those two speakers are what took me down the Omni path, resulting in scoring the Duevel Planets then Enterprises to test.

The 360 Peak still gets regular use—it’s my primary “mobile” portable Bluetooth speaker indoors. It’s perfect for when you are working and moving around in a room and want the whole room to be a “sweet spot”. When cooking, I just throw it on the end of the “L” counter island section and have good sound everywhere in the workspace.

The HK one has more SPL capability but tethered to wall power. I’ve used that a lot when working in the garage. Can’t recall if mentioned here or a different thread, but had a new garage door installed not too long ago, asking the crew “tunes or no tunes?” Tunes requested, so I threw the HK Omni on a workable off to the side a bit. After a couple songs, the crew chief stopped and said “ok—where in the heck is the music coming from—sounds like everywhere and see no speakers”. Pointed to it on the table with some other stuff and he just looked at me. He inquired about it, telling him I got from Amazon. He stopped installing, mumbled something, ordering one on the spot.

Omnis may still be controversial to many, but I say they do things no other speaker can and are unparalleled in providing music across a wide listening area. Like one member said much earlier in the thread, the perfect “party” speaker.

I'm finishing up the SDA conversion of my MTM's, then I'll be back on this project. Do you feel that a smallish enclosure running a 5.25" midrange/tweeter combo on the desktop, then adding in a subwoofer would be ideal?

 

[jim1274]

Omnis will fully engage the room. If you like the sound of your listening room I guess it’s a good thing? I don’t want to hear my listening room.

I ended up with the Omnis very close to my listening position (4’ equilateral triangle), increasing direct to reflected sound, taking more of the room out of the equation. That surprisingly didn’t reduce the soundstage size and speakers still completely disappeared.

 

[jim1274]

I'm finishing up the SDA conversion of my MTM's, then I'll be back on this project. Do you feel that a smallish enclosure running a 5.25" midrange/tweeter combo on the desktop, then adding in a subwoofer would be ideal?

I’ve never used a subwoofer with any of my Omnis, but don’t see why it would be any different than using with regular bookshelf speakers?

All the speakers used here in the Omni comparisons (other than the BMRs) were floor standers with decent (or better) low end extension.

 

[Peterinvan]

If you are not looking for an intimate spacious sound stage, the B&W Zeppelins are very impressive.

 

[xschop]

Will be experimenting on a coaxial driver design soon. Thanks for the ring tweeter idea! . I can make it seated within the cone using a stand-off rod interfaced from the pole piece or just machine a lengthened pole-piece for the 38mm coil ID... Also can make the magnet top plate wider for a standard spider....

Ideas welcomed as always....