Omnidirectional Quad Speakers

[Quad grant me serenity]

Dear QQ,
I listened to omnidirectional speakers today in a stereo setup, and there were fascinating. The store manager told me that in his opinion they would be even better in a quad setup. He actually thought that would be the ultimate combo. Now, has anyone here tried THAT?
(Also, since I am a vintage fan: had anyone tried vintage omnidirectional speakers?)

 

[par4ken]

Advice has long been that omnidirectional or even direct/reflecting type speakers are not ideal for quad (or stereo) as they blur the stereo image. However it might depend. If you want to extract ambiance from the rear speakers they could be great for that. So no hard and fast answer other than to try it to see how it sounds! And report back!

I once experimented building an omnidirectional speaker with the same drivers on all four sides. It was terrible as it lobed badly. The sound peaked in front of each driver and disappeared at the corners. A true omni, one without lobing would be a different story.

 

[Doug G.]

In 1968, for confirmation, I received this little Coronado consolette (not this actual one but exactly like it) and the speakers were built in on the ends. The drivers faced up toward plastic cone-shaped diffusers and were thus, "omnidirectional." It was similar to the Zenith omnidirectional speakers of the same period.

I liked it but me being me, it wasn't long before I decided I wanted the speakers farther apart and I separated them from the rest f the unit so I could move them apart.

I agree that the stereo image is compromised with this arrangement and maybe ambiance is enhanced but it's not that dramatic. I feel regular, more directional speakers are better for quad.

Doug

 

[Horbus]

There is a big fan community for "OHM" Speakers or even Bose 901's and I would say it's just a matter of taste how you listen to music. I for myself for most of the time don't listen to stereo with only 2 speakers engaged but all others as well in a so called "Extended Stereo" mode of my AVR. I do like it more when the room is filled with music instead of just coming from the front side. So I would be going with omnidirectional speakers as well. My speakers are sort of omnidirectional (tweeter on the front, midbass on the sides to compensate for the 90° phase shift of the speakers 1. order (6 dB) crossover.

 

[Quad grant me serenity]

Thank you for your (non-definitive) answers! What I liked about the speakers i heard was that the music became more physical, like hearing a band sitting in front of the stage in a theater. Sure, it was not a razor sharp line between right and left at all times, but very alive and weighty.

 

[andyp]

I remember Julian Hirsch from Stereo Review testing a pair of OHM speakers in the mid to late 70's. "Julian Hirsch of Stereo Review had reviewed their top-of-the-line, Model III and said they had “never heard better sound reproduction in our home, from any speaker of any size or price." He also said they were the only speakers to rattle everything in the test room.

 

[rmorit01]

From a vintage speaker perspective Sansui had their SF line of omnidirectional.

I have used SF-2 as rear/side speakers and as end tables next to a couch. They had two 8" woofers. One face down and the other up. Facing up was a plastic curved surface to reflect the sound 360 degrees with a tweeter.

My current quad setup are Epicure M202 which have a woofer and tweeter on 2 faces. So you can turn them with one side facing into the listening position and the other side is reflecting off a wall. I like how the M202 fill my oddly shaped listening space and the bass they can produce.

Though depending what I am listening too I will jump from a stereo configuration, to quad to a 5.1 depending on the source. For me the Omni and direct loose the effect of hearing one particular instrument in the sweet spot that can emerge with directional speakers. I have Sansui LM series speakers that have cone tweeters that seemed magical at creating an effect in the sweet spot but required perfect placement for them to be magical. I just prefer the more encompassing, immersive effect of the M202s for my space
I still have the SF-2 that got with a set of Sansui SP-2500s... Sansui, like others pitched the omni-directional approach as part of the marketing for the SF-2.

Bob

 

[ar surround]

Now, has anyone here tried THAT?

My two cents on this:

I have never used omnidirectional speakers, but I heard them in audio salons and they were impressive playing stereo. To get omnidirectional speaker style sound, I use Auro3D with five ceiling speakers (5.1.5) to enhance quadraphonic recordings. My opinion on using omnidirectional speakers is this:

I find that Auro3D is excellent at enhancing quadraphonic recordings. It makes the images of instruments embedded in the speakers larger and more realistic. Overall it yields a more satisfying sound field. However, when it comes to enhancing modern 5.1 recordings it tends to muddle things up and I don't use it on them. Dolby Surround (7.1.4) is even worse at muddling up 5.1 music. I suspect this is because modern 5.1 mixes already have more of a "big" sound to them with a lot of front to back ambience / leakage. Old quad recordings tend to be more discrete with less front to back 'leakage', especially those designed for matrix quad.

So I would say that you might find the omnidirectional speakers to be excellent when playing quad recordings, but a bit dodgy when it comes to modern 5.1 mixes.

 

[barfle]

There is a big fan community for "OHM" Speakers or even Bose 901's and I would say it's just a matter of taste how you listen to music. I for myself for most of the time don't listen to stereo with only 2 speakers engaged but all others as well in a so called "Extended Stereo" mode of my AVR. I do like it more when the room is filled with music instead of just coming from the front side. So I would be going with omnidirectional speakers as well. My speakers are sort of omnidirectional (tweeter on the front, midbass on the sides to compensate for the 90° phase shift of the speakers 1. order (6 dB) crossover.

I had a friend who had just bought a pair of 901s, and I have to admit, it was probably the worst effect I’ve ever heard a functioning speaker have on a stereo image. Maybe some of those old Phil Spector “wall of sound” mono 45s would be OK, but IMNSHO, those were awful.

I believe he liked them, but I sure didn’t. To each his own, in that case.

It definitely turned me off speakers that tried too hard to not be point sources. I don’t know if those spherical “omni” speakers would have a similar effect. Probably interesting, but not worth the investment to me.

 

[par4ken]

Away back in the "Show Us Your Gear" thread are pictures and description of speakers that I built away back about 1979. I still use them in my "man cave". They still sound fantastic, IMHO you would be hard pressed to find better sounding commercially made speakers anywhere.

They use four Philips dome midrange and four Philips dome tweeters in each cabinet. They are the same drivers that I had experimented with in the failed Omni design.

I simply constructed a large floor standing speaker nearly four feet tall with two 12" Philips woofers. Two mids and tweeters are mounted side by side on the front, the other two on the top. My intent was not to make a direct/reflecting type speaker but I wanted to be able to clearly hear each speaker as I stood and walked around the room. The other consideration was that was the only way that all those speakers would fit in a reasonably sized cabinet.

The design worked and sounds fantastic. It doesn't seem to blur the sound image. The theory of using multiple drivers is that each speaker has to move less for a given volume level, which translates to lower distortion.

 

[par4ken]

I had a friend who had just bought a pair of 901s, and I have to admit, it was probably the worst effect I’ve ever heard a functioning speaker have on a stereo image. Maybe some of those old Phil Spector “wall of sound” mono 45s would be OK, but IMNSHO, those were awful.

I believe he liked them, but I sure didn’t. To each his own, in that case.

It definitely turned me off speakers that tried too hard to not be point sources. I don’t know if those spherical “omni” speakers would have a similar effect. Probably interesting, but not worth the investment to me.

At one time many people around here thought that Bose 901s were "the speaker" to have. It seemed almost like a cult. I always found them lacking in (low) bass. A local "music man" used them but they were turned around back facing the front. Maybe that is why they didn't sound so bad.

 

[barfle]

Away back in the "Show Us Your Gear" thread are pictures and description of speakers that I built away back about 1979. I still use them in my "man cave". They still sound fantastic, IMHO you would be hard pressed to find better sounding commercially made speakers anywhere.

They use four Philips dome midrange and four Philips dome tweeters in each cabinet. They are the same drivers that I had experimented with in the failed Omni design.

I simply constructed a large floor standing speaker nearly four feet tall with two 12" Philips woofers. Two mids and tweeters are mounted side by side on the front, the other two on the top. My intent was not to make a direct/reflecting type speaker but I wanted to be able to clearly hear each speaker as I stood and walked around the room. The other consideration was that was the only way that all those speakers would fit in a reasonably sized cabinet.

The design worked and sounds fantastic. It doesn't seem to blur the sound image. The theory of using multiple drivers is that each speaker has to move less for a given volume level, which translates to lower distortion.

I recall seeing an array of medium sized speakers in a Popular Electronics (?) article way back when. The overall idea was that the array would push as much air as a large cone, but without the issues of cone flexing that a larger cone would have, looking acoustically like a large, very stiff cone.

It still seems like a decent idea, although driving that many coils could be problematic.

 

[par4ken]

I recall seeing an array of medium sized speakers in a Popular Electronics (?) article way back when. The overall idea was that the array would push as much air as a large cone, but without the issues of cone flexing that a larger cone would have, looking acoustically like a large, very stiff cone.

It still seems like a decent idea, although driving that many coils could be problematic.

That was in part what inspired me! I used four drivers in series/parallel to maintain 8 ohm impedance.

 

[barfle]

That was in part what inspired me! I used four drivers in series/parallel to maintain 8 ohm impedance.

The issue with series connections is damping factor - it pretty much vanishes if there’s an impedance between the coil and the amplifier. Maybe that’s not a problem, depending on the driver.

These days I probably couldn’t hear the difference.

 

[jimfisheye]

Genuine omnidirectional? Not just very wide dispersion?

If you had a sound event to broadcast in a space where you wanted continuous coverage, and especially if the audience would be surrounding the broadcast point(s), very wide dispersion would be welcome.

Surround listening surrounds the listening space with a speaker array and defines the sound stage inside it. We're looking to recreate a recording that includes any spacial or ambient elements in a neutral transparent listening space. Not just broadcasting sound into a space but a precise virtual reality level of reproduction. Things go from zero to 100 with that. There might be a number of ways to listen to a recording while letting a listening space influence or alter it that sounds good. But there's only one way to reproduce a recording accurately to hear it as intended (for good or bad).

There could be examples with larger listening spaces where wider dispersion speakers would make sense. Where we're covering a larger area with each channel. But probably still not true omnidirectional. We never want to create sound elements (reflections, etc) beyond the recorded content.

Some live sound situations can benefit from wider dispersion. We're trying to get some main mix elements into everyone's ears! If you're in the front row in the middle, you probably want to still hear the lead singer. Not wide enough speaker stacks on the sides might mean you'd have to put up front fill speakers for that front center section. No one is thinking about the precision of the live stereo mix when they can't hear the lead vocal! (Or the surround mix if this is a Pink Floyd concert 1967-1981.)

So no hard right/wrong answer. Probably would not work for most listening rooms because the reflection outside of the listening area would get in the way. Could still be creative and welcome for that but would fly in the face of 1:1 reproduction.

 

[par4ken]

The issue with series connections is damping factor - it pretty much vanishes if there’s an impedance between the coil and the amplifier. Maybe that’s not a problem, depending on the driver.

These days I probably couldn’t hear the difference.

Damping factor is important with woofers not so much tweeters and midranges. Most crossover networks employ resistors as well. I bi-amp which helps matters especially with damping of the woofers.

Edit: I don't believe (but might be wrong) that there is any problem/penalty when identical speakers are connected in series. Their impedances exactly match, there should be no difference between that and having a single speaker of double the impedance connected. Also the amplifier should be able to better damp a higher impedance load.

 

[multi_est]

rear speakers are the only place for omnis and work in extended stereo and of course in surround.

https://cdn2.imagearchive.com/quadraphonicquad/data/attach/40/40719-conn-r.jpg

 

[par4ken]

rear speakers are the only place for omnis and work in extended stereo and of course in surround.

https://cdn2.imagearchive.com/quadraphonicquad/data/attach/40/40719-conn-r.jpg

Sugden made more than just turntables then! Connoisseur was the best bang for the buck back in the day!

 

[MidiMagic]

I recall seeing an array of medium sized speakers in a Popular Electronics (?) article way back when. The overall idea was that the array would push as much air as a large cone, but without the issues of cone flexing that a larger cone would have, looking acoustically like a large, very stiff cone.

It still seems like a decent idea, although driving that many coils could be problematic.

I have two such sets of speakers my father built. They sound great even 60 years later.

 

[Sonik Wiz]

I have two such sets of speakers my father built. They sound great even 60 years later.

But do they image properly?

Is it possible to to get a precise center front vocalist to do thar? I don't think so.