[TheChairGuy]

I've found, over time, the less directional a speaker is, the more I like what's coming out of it.  I heard an extremely convincing argument for omni-directional speaker set-up from Shahinian Acoustics 20 years ago (I think Richard Shahinian is a disciple of Stuart Hegeman...a proponent of such designs).

Anyhow, I think I forgot that convincing lesson until I heard a cheapie Mirage omni-speaker at Best Buy (well, the Magnolia area inside it, actually) recently.  While I could fry an egg on that tweeter, it had an overall spaciousness that was fantastic   It sounded like the 'real' event - at least in terms of imaging (so crucial for goosebumps in this hobby, I've found).

I like my current (cheapie) Linaeums pretty well - with a bi-polar / separate mounted ribbon tweeter - but it has front firing woofers that spoils the spaciousness aspect.  I think it's time I upgraded now - the rest of my system has been pretty well figured out (for now). Finally.

So there's Shahinian, Ohm, Mirage, and the Hegeman stuff made by Don Morrison in Toronto that I know of. 

Has anybody heard the Decware RL stuff?....they're appealing as they do without any crossovers on the main drivers.

[lonewolfny42]

John...

You might keep your eye's open for a pair of Mirage M-3's or M-3si's used....a bi-polar speaker. I've seen them on Audiogon every once in awhile...$500.00 to $800.00 range. Their both good speakers....and "spaciousness" is a very good description.

M-3 Review...

M-3si Review...

M-3 Info...

M-3si Info...

I've owned my M-3's since 1989...and I still enjoy them daily...

[JLM]

I've heard a couple of the older Decware RLs (the cylindrical ones).  The mid/bass driver was highly "customized" with the cone flipped (face down) so that the voice coil/magnet was in front (below and inside the cylinder).  A couple of tweater options were available (small dome or ribbon) that were both directional with just a cap to protect.  Steve has a bit of DIY in him, so much of his stuff is released a bit too soon IMO, so the base design (that adjusted the air vent at the bottom) and resistor values were left up to the user.  The tweeter could be adjusted by bending the thin metal arm that connected it to the cabinet.

The overall image I heard floated above the speakers in about a 12 foot diameter "cloud" versus dipoles/bipoles that provide a wall of sound and bass load the room more in one dimension.  To me neither provide a highly detailed, resolved, image.  OTOH they can sound more natural (I don't hear individual instruments/singers during live, unamplified performances), but YMMV.  The Radials were supposed to be less room interactive, but I don't know how they'd work in a room without a flat ceiling 8 - 10 feet above the floor.  Fasinating sound, yes.  Would I want to live with it (assuming I only had one good room for sound)?  I don't know.

[opaqueice]

Linkwitz Orions are dipoles throughout the spectrum.  MBL Radialstrahlers also sound amazing, and I think their sound pattern is close to fully symmetrical (in the horizontal plane).  The Bang&Olufsen Beolab5 is also an interesting design - the tweeter radiates into the front 180 degrees or so.

[honesthoff]

Don't overlook the Duevel line.

[Bob in St. Louis]

John, sounds like you're a candidate for open baffle.  aa

Either that or meet me at Steve D's house on Oct 5,6,7th for the DecFest if you'd like to hear the RL's (among everything else he's got).
More than a few forum members will be there.

Bob

[Vinnie R.]

Don't overlook the Duevel line.

Here is a review:

http://www.sonicflare.com/archives/duevel-planet-review-by-sandy-greene.php

[Danny Richie]

For what it is worth I have been working with omni direction designs for a while now.

It started with the A/V-1RS. It was a omni directional on wall designed to be used as rear surrounds. It was awesome. The large non-localized sound field was perfect for the application.

Then I tried one as a free standing speaker for those that can't mount them on a wall. I came up with the A/V-O. These were not only good for the rear surround application but were excellent for left and right main speakers. It uses the same drivers as our A/V-1 model, but total blows them away as main speakers.

This lead me to do a version with the Neo tweeter to use as rear surrounds for my OB (open baffle) series speakers. With this one I also added an extra low frequency woofer right behind the main woofer. These things are incredible and easily give the larger OB-5 and OB-7 a run for their money. They won't handle the power or reach the output levels of the larger OB designs but match them otherwise.

The sound stage and imaging of these things are awesome and much closer to real live playback.

I am surprised that I haven't seen more companies trying stuff like this. Linkwitz did one called the Pluto and very favorably compared it to his Orion. Having worked with this configuration now, I can understand why.

To see info on the models I mentioned below, check my kits page.

http://www.gr-research.com/index.asp?PageAction=VIEWCATS&Category=2

[Bob in St. Louis]

Danny, I built a "semi rip-off" baffle/enclosure design of your A/V-1RS in an attempt to have my own omnidirectional rear surrounds. Works pretty well. The main difference is that mine is open on the lower half of the front, and entire bottom. Also I used a ten inch driver.
I go back and forth about whether or not I want to try a true radial either mounted vertically (traditional), or a shorter version mounted on the wall horizontally.

Bob

[Brucemck]

Danny's AV-O speakers are amazing.  I heard them at last year's RMAF and frankly was astounded to learn that I wasn't listening to the much larger OB-7 speakers in the room set up right next to them.  for the money they're a steal!

(His on wall omni AV1-RS surrounds are also pretty impressive.)

[tonyptony]

I've found, over time, the less directional a speaker is, the more I like what's coming out of it.  I heard an extremely convincing argument for omni-directional speaker set-up from Shahinian Acoustics 20 years ago (I think Richard Shahinian is a disciple of Stuart Hegeman...a proponent of such designs).

"Dear, dear John..."

"A double Dear John John!"

(for MASH fans  )

Richard is still out there. Give him a call. You know you want to do it. You know you want to buy a pair of Shahinian speakers. Sure, there are other omni types on the market; a few of them are even pretty good. But you've heard Richard's speakers...still thinking about them 20 years later  ; pound for pound and dollar for dollar you know you won't be able to get an omni (or most any other type, for that matter!) that will outdo the musical gloriosity of a pair of Shahinians.   

[Danny Richie]

Brucemck, those were the O-3's that you heard.

[TheChairGuy]

I read a little on the Duevel speakers last night, too (thanks guys!)....interesting speakers.  They start at a very reasonable $1195.00, but rapidly escalate from there.

I guess the question I have now is....open baffle = omni-directional?  They seem related, but different (1st cousins of sorts) 

Danny - I have to look over your offerings.  I'm impressed enough by your M-165 driver (as you may remember I swapped them in my Linaeum for the cheapie Peerless' they came with) that if you use them in your OB series, I'm sure they're worthy of attention  (I've been meaning to shoot you a quick note on how impressed I am with them for the low cost - so there ya' go  )

tonyptony - I might just have to hear the Shahinians again.  I didn't have any appreciation for classical/orchestral back then, and I was still impressed.   

[Scott F.]

Hey TCG,

Don't forget about the Allison One's.

[TheChairGuy]

wow - Allison - that's an old name.

$6400 now - whoa - furniture grade and all   If I can get past the cost (which I likely can't), the following is the deal killer for me, tho:

Recommended placement for the Allison One loudspeakers is 10’ apart .

[*Scotty*]

A key thing to remember is that the Allison Speakers only radiate into the forward hemisphere, they are sort of the opposite of a bipolar design.
I don't think omni-directionality is is a prerequisite for a spacious presentation. I went from MG III's to forward radiating loudspeakers and really didn't loose any spaciousness and I gained image precision. I think the key to having the illusion of live music in your listening room is not having it sound like it is stuck in the two boxes in front of you. You should be able to play a single loudspeaker at a time and still have the loudspeaker disappear. An omni directional design can do this easier, but this is not an unreasonable demand to make of a forward radiating only loudspeaker.
Scotty

[TheChairGuy]

Scotty, et al...most of my listening is non-critical.  My office, and system, is in the same room so I normally listen all day when I'm home.  8-10 hours is normal (I eat a lot of tubes in my amps  but they are cheap ones, fortunately)

So, between speaking on the phone (often while typing and chewing gum  ), getting up for faxes, the mail, deliveries, etc. I rarely get to critically evaluate anything.  But, what's lost in quality time is spent in quantity...I can tell something's amiss qucik in my system as I listen to it so often, and for so long.

Forward firing mid/woofers are also 'in your face'...no matter the design if they fire forward.  An enveloping image portrayal, laid back a bit for depth perspective is probably an efficient way for me to enjoy my system and do all the work I have to daily.  That's pretty much why I'm asking about omni-directional designs out there today

[DaveC113]

I used to have a pair of Mirage M990 Bipolar speakers... interesting design with a fullrange driver on the rear, 2 identical 6.5" drivers crossed over at different points and a Ti dome tweeter on the front. It was ported front and rear as well. I listened to the smaller M-series too, and thought they were superior to the M7s, but I would have rather had the M3s. For the difference in price, I was happy with the 990s.  

I moved to a small space, and currently have Omega XRS... I would love to upgrade to the Omega Bipolar speakers, they can be set up bipole or dipole.... I enjoy listening to the XRS a lot more than the Mirage speakers, bipolar or not, fwiw.

Also, M&D have an "Omni-Harmonizer":

http://www.mark-daniel.com/Pro_En.asp?ProID=8

With the great reviews these speakers are getting, they seem like they are worth checking out.

Dave  

[Duke]

Hello Chairguy,

I'm a fan of what omni-speakers do well, though I don't actually sell any omnis at this time.

Let me give a brief overview of why I think omnis sound good, as the psychoacoustic principles behind it are imho at the heart of good loudspeaker design.

The goal is to recreate, as closely as possible, the perception of being present at a live performance, and the reverberant field is critical to this.  The ear finds a late-arriving, diffuse, well-energized, spectrally correct reverberant field to be rich, warm, lush, and very pleasing - enhancing timbre and giving a sense of ambience, spaciousness, and envelopment.  That delicious lushness we hear in a good recital or concert hall is almost entirely the result of the reverberant field's characteristics.  This is where omnis shine.  In my opinion, doing a good job with at least the spectral balance of the reverberant field is an important aspect of any loudspeaker designed for anything other than nearfield listening.

Moving back into the home listening room, unfortunately not all reflections are good.  In general, reflections arriving earlier than 10 milliseconds after the first-arrival sound are likely to be detrimental to imaging and timbre.  This roughly corresponds to a path length difference of eleven feet.  Now in a large enough room an omnidirectional speaker will not have early sidewall reflections arriving within this time window, but in a smaller room it's likely to happen.   Most speakers in most rooms will have floor and ceiling bounce reflections arriving within that time interval (line source speakers being an exception).

Note that most speakers generate a reverberant field that has a significantly different spectral balance from the first-arrival sound due to radiation pattern issues.  So there are a lot of speakers out there whose tonal balance goes down hill the larger the relative contribution of the reverberant field.  Omnis, however, are very good to excellent in this regard (varying somewhat from one speaker to another - some omnis are more omni than others).

Line source dipole speakers (Maggies, SoundLabs, Apogees, etc.) are an especially elegant approach.  Their inherent directivity in the vertical plane avoids the early floor and ceiling reflections, and if they can be placed six feet or so in front of the wall their backwave energy arrives late enough that its contribution is almost entirely beneficial (I still like to diffuse the backwave a bit).   The early sidewall reflection may still be an issue, depending on radiation pattern and amount of toe-in.

Likewise, a bipole will generate a rich reverberant field.  In fact, my first commercial system was a bipolar.  Bipolars have some interesting characteristics and challenges, and several variatons have been tried.  Although not very many bipolars have made it to the marketplace, a fair amount of innovation has gone into those that have. 

Of course there are even more variations among omnidirectional systems, and most are not really true omnis.  Even those with uniform 360 degree horizontal patterns (Duevel, MBL, Wolcott, Morrison) have vertical directional characteristics that can and do impact the power response and therefore the spectral balance of the reverberant energy.

I particularly like Richard Shahinian's word, "polydirectional".  That word includes omnis, bipolars, dipolars, and his own carefully-chosen multi-directional configurations.  Imho Richard's polydirectional speakers are very intelligently designed to work well in most people's rooms.  They address the early reflection issue by being very low to the ground and bouncing a lot of energy off the upper walls and ceiling.  In a small room, this increases the time interval before the arrival of the first reflections.  If I wasn't pumping my spare nickels into my own line, I'd probably be a dealer for him.

The speakers that I currently build get the spectral balance of the reverberant field right and are designed to be listened to off-axis so they aren't so much "in your face", but some people (and some rooms) prefer more energy in the reverberant field relative to the direct sound.   This is something polydirectionals do better than my off-axis monopoles.  So I have recently revisited the polydirectional concept, building and auditioning several different configurations using identical drivers.  One of the configurations I tried was clearly preferred by my own ears and also by my portable analog real-time spectrum analyzer, who doubles as my wife.  So at some time in the not-too-distant future I'll probably be adding one or two polydirectional types in my lineup. 

Duke

[TheChairGuy]

Super responses all - thank you - I'm taking it all in 

Just remembered Norh makes a Prism series of 'multi-directional' speakers (at least I think, info is a bit thin), too http://www.norh.com/products/prism/index.html