Poly Directional Loudspeakers

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joerest

Poly Directional Loudspeakers
« on: 16 Apr 2017, 02:14 am »
Owned Omni directional (AKA poly directional) loudspeakers from 1975 to 2012. Started with the Bose 901's series 2, ended with the Shahinian Hawks. Owned Shahinian's since 1983. Got to a point where I could not take another day of listening to non-directional loudspeakers. Make no mistake however, I did enjoy them for over 30 years, so I am not bashing them under any circumstances. but would like to share experiences with those of similar ilk. I know for a fact however, I will never own them again. Any thoughts ?

S Clark

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Re: Poly Directional Loudspeakers
« Reply #1 on: 16 Apr 2017, 03:08 am »
I've had a pair of Design Acoustics D-12 speakers since around 1978.  To this day, they do a very good job of creating a believable full orchestra.  Not the best in pinpointing an instruments location, but what they do well, hall ambience,  they do very well.  With a downward firing woofer, upward firing midrange, and 9 beaming tweeters in a ported dodecahedron, they would be a nightmare to try to design by computer.
Mine look much like these:

joerest

Re: Poly Directional Loudspeakers
« Reply #2 on: 16 Apr 2017, 05:22 am »
S Clark: The first thing that comes to mind looking at your photo, is the size of the room needed to accommodate those omni's. They are truly omni's; and need to be in an open space. Either you are a single guy, or your wife has a broad WAF.  When I owned the Shahinian Hawks I did have a fairly large sound room. I have sinced downsized, and could never accomodate them today. Even small omni's are tough to accommodate in most domestic environments. Another thing that comes to mind, is the instances when you look to do some quiet nearfield listening. Not an option. On the other hand, I am sure orchestral music can be served well. I was an omni guy who has never enjoyed orchestral or classical music. In any case they look like an engineering feat, well built. Enjoy.

srb

Re: Poly Directional Loudspeakers
« Reply #3 on: 16 Apr 2017, 07:49 am »
I haven't seen any more ambitious omni loudspeaker than the RAAL Requesite Eternity loudspeaker from Aleksandar Radisavljevic of RAAL.  It was apparently shown at an audio show in 2009 but I don't know if there was ever any significant production.

With 5 X 15" woofers in a cast bronze 6-sided polyhedron and 18 X 3" midrange drivers + 15 RAAL ribbon tweeters in an upright 6-sided/circular column, this was probably one loudspeaker actually worth its projected $88K estimated price, given its driver complement and complicated construction.

For those that missed it, construction details were spotlighted in an interesting 6Moons article in September 2008.

Steve

  

joerest

Re: Poly Directional Loudspeakers
« Reply #4 on: 16 Apr 2017, 11:57 am »
So, a shout out to Omni lovers, do you feel they expand or shrink the overall soundstage ? Do they help to recreate natural space ? Is the omnidirectional presentation worth the loss of pinpoint imaging and detail focus ? Or maybe you feel they improve imaging and focus ? I am sure the execution is equally important. When owning omni's myself, I felt the need to control the level of non-directionality. Would have loved to add or subtract the reflective sound based on room acoustics or my mood at the moment. Or even based on the recording environment and/or musical ensemble. Maybe even control the relationship between the rear, inner and outer projecting sound. Maybe my "outgrowing" of omni's had to do with lack of control ? Or maybe the inability to recreate different venues ? Another issue is the effect of omni's on unnatural environments like recording studio's. Not to mention their influence on electronic effects like reverb or echo.

JLM

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Re: Poly Directional Loudspeakers
« Reply #5 on: 16 Apr 2017, 12:25 pm »
Omni's require bigger listening spaces and even then impose more of the sonic characteristics of that space on the playback sound.  And as long as the speaker can "fill the space" bigger rooms will always sound better regardless of type.

Soundstage/imaging presentation is an individual listener's decision but as always we are prisoners of how the recording was mixed/mastered (which was done with direct radiating speakers), so can be a real crap shoot using various recordings with other speaker types. 

Of course these considerations also apply to dipole, bipole, array, and other non-direct radiating speakers.

joerest

Re: Poly Directional Loudspeakers
« Reply #6 on: 16 Apr 2017, 12:51 pm »
Let us also consider how directionality changes with frequency. Do omni's allow beeming to increase as does the frequency? Or do they alllow the triangle to sound more natural not coming from a keyhole ?

studiotech

Re: Poly Directional Loudspeakers
« Reply #7 on: 16 Apr 2017, 01:15 pm »
. When owning omni's myself, I felt the need to control the level of non-directionality. Would have loved to add or subtract the reflective sound based on room acoustics or my mood at the moment. Or even based on the recording environment and/or musical ensemble.

Interestingly enough, I believe the new B&O system is capable of just that trick.

http://www.bang-olufsen.com/en/collection/speakers/beolab-90

Greg

joerest

Re: Poly Directional Loudspeakers
« Reply #8 on: 16 Apr 2017, 08:27 pm »
Dear Studiotech: Just my humble opinion, and not out to disagree, but was once told at a B&O demo that the speaker was 100% digital. Did not have the heart to tell the young B&O rep that humans don't have the ability to listen to music in digital. Lost all interest in B&O after that. Think it is another high end manufacturer that has lost it's way. Don't get me wrong, they all have to stay afloat in any way they see fit. But that doesn't mean I (as an old world audiophile) have to buy what they are selling. Sometimes I think the goal is to stuff as much stuff in the cabinet as possible. It loses the art after a while.

grsimmon

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Re: Poly Directional Loudspeakers
« Reply #9 on: 16 Apr 2017, 08:41 pm »
Keep in mind,  Polydirectional and Omnidirectional are NOT the same thing.  Different launch pattern, with polydirectional have some drawbacks due to lobing.   As Don Morrison says,  you can have drivers firing 6 ways to Sunday, but it won't produce a coherent launch.

MBL,  Duevel,  Mirage,  Ohm Walsh,  German Physiks,  and Morrison Audio are closer to a true Omni speaker.

Others like Bose,  Shahinian and others discussed so far are poly's.   

I currently run a 3 front speaker setup:   Mirage OMD-28's,   with a small Mirage bookshelf for center ambience/fill in,   using a McCormack MAP-1 analog preamp to create the center signal.   Three things I will say  1)  I'm never going back to conventional front-firing speakers,   2)  I'm never going back to 2 channel stereo.   3)  I'm never again using a "normal" center speaker in MTM arrangement, again due to problems with lobing and launch pattern.  A bookshelf or even floorstanding speaker is much better for center duties.

Hopefully someday I can buy some Duevel's or Morrisons.    Morrisons have the added benefit that they can be run actively using an external crossover.


studiotech

Re: Poly Directional Loudspeakers
« Reply #10 on: 17 Apr 2017, 02:55 am »
Dear Studiotech: Just my humble opinion, and not out to disagree, but was once told at a B&O demo that the speaker was 100% digital. Did not have the heart to tell the young B&O rep that humans don't have the ability to listen to music in digital. Lost all interest in B&O after that. Think it is another high end manufacturer that has lost it's way. Don't get me wrong, they all have to stay afloat in any way they see fit. But that doesn't mean I (as an old world audiophile) have to buy what they are selling. Sometimes I think the goal is to stuff as much stuff in the cabinet as possible. It loses the art after a while.

To each his own, but don't let an unfortunate statement get in the way of what they've accomplished with these speakers.  Do yourself a favor and read up on the technology being used.  Certainly pushing some boundaries, which more than  most audiophile companies peddling near $100,000 speakers can say.

S Clark

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Re: Poly Directional Loudspeakers
« Reply #11 on: 17 Apr 2017, 03:24 am »
S Clark: The first thing that comes to mind looking at your photo, is the size of the room needed to accommodate those omni's. They are truly omni's; and need to be in an open space. Either you are a single guy, or your wife has a broad WAF. 
I obviously have a wife that I don't deserve.  She puts up with a lot.  You can see my Design Acoustics D-12 peeking out from behind the speakers that really take up space! 



joerest

Re: Poly Directional Loudspeakers
« Reply #12 on: 17 Apr 2017, 04:07 am »
S Clark, you are certainly a lucky guy.
Studiotech, I will take you up on that, and look into the B&O  technology. My skepticism stems from all those switching class D amplifiers in a single box. Seems the limits of space inside an enclosure is more important than actually using the best sounding device. I will try and look at it with an open mind nevertheless. I would much rather hear opinions on poly/omni transducers which got it very right or very wrong. From a pure listening perspective. From my many years of listening to many different attemps, I would say some omnidirectionality or polydirectionality can make a speaker very palatable. Sometimes softening the presentation in a domestic environment is exactly what the doctor ordered. It can give the listener the feeling if being immersed in sound. Very relaxing and involving. On the other hand, a directional speaker will almost always render more detail. Maybe a combination of the two is the best compromise? Or follow direction of S Clark and get a pair of both types. Anyone know a good divorce lawyer ?

JohnR

Re: Poly Directional Loudspeakers
« Reply #13 on: 17 Apr 2017, 09:58 am »
Does "poly directional" mean "radiates in a number of different directions at the same time" or "is capable of different radiation patterns at different times"?

(Genuinely confused  :scratch: )

JLM

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Re: Poly Directional Loudspeakers
« Reply #14 on: 17 Apr 2017, 11:25 am »
Keep in mind,  Polydirectional and Omnidirectional are NOT the same thing.  Different launch pattern, with polydirectional have some drawbacks due to lobing.   As Don Morrison says,  you can have drivers firing 6 ways to Sunday, but it won't produce a coherent launch.

MBL,  Duevel,  Mirage,  Ohm Walsh,  German Physiks,  and Morrison Audio are closer to a true Omni speaker.

Others like Bose,  Shahinian and others discussed so far are poly's.   

I currently run a 3 front speaker setup:   Mirage OMD-28's,   with a small Mirage bookshelf for center ambience/fill in,   using a McCormack MAP-1 analog preamp to create the center signal.   Three things I will say  1)  I'm never going back to conventional front-firing speakers,   2)  I'm never going back to 2 channel stereo.   3)  I'm never again using a "normal" center speaker in MTM arrangement, again due to problems with lobing and launch pattern.  A bookshelf or even floorstanding speaker is much better for center duties.

Hopefully someday I can buy some Duevel's or Morrisons.    Morrisons have the added benefit that they can be run actively using an external crossover.

+1 on differentiating between omnidirectional and polydirectional.

JohnR:  go with your first guess.

joerest

Re: Poly Directional Loudspeakers
« Reply #15 on: 18 Apr 2017, 06:31 am »
Maybe we can get back on track here by bringing this thread on-topic. Was listening to my direct radiating, front firing speakers today, and felt the direct detail was just too relentless. It could have just been my mood-of-the-moment as yesterday's listening session was perfect in every way. But can say for sure, if my ears get used to a louder than usual  level, only maintaining that level will give me the bass drive and detail that will satisfy. But after listenimg fatique sets in, I realize I am overtaxing the room. Harking back to my years of owning poly directional speakers, this happened less often. The dilemma there was the sessions when I was bored due to lack of detail and directional queues. I am now in the process of researching new speakers. Whereas I don't feel omni/poly directionality is the answer, maybe a speaker like the Shahinian Arc or the Neat Lota Alpha's would be worth looking into. They both project the sound slightly upward, taking it just off axis to the listeners ears. I was never a proponent of "tow-in" or headphones as they accomplish the same thing. Any thoughts ?

joerest

Re: Poly Directional Loudspeakers
« Reply #16 on: 23 Apr 2017, 04:53 am »
Well being here at the Axpona show, I was able to dismiss a couple of possibilities. First, the Neat Lota Alpha 's are simply too small to be regarded as a real contender (or answer to the age old direct/poly directional question). They are good for what they do, but are way too small to be considered a high end speaker. Secondly, I took Studiotech's advice, looked into the B and O 90 loudspeakers, listened to a presentation on their development and technology, watched a video and actually auditioned the speaker at the Axpona show. In a word, they stink. Through it all, the proof is in the listening. As a caveat, this is only in my very humble opinion. I could be wrong. All and all, I am at a crossroads. Again heard the omnidirectional MBL Radialstrahler's , and am not sure I like them, or they fulfill any audiophile purpose. In their "omnidirectionality", they shrink the soundstage, and smear image. They do many things right, but soundstage and instument placing are not two of them. This brings me to the point, that omnidirectionality is not the answer, but maybe polydirectionality is. Maybe neither is any good, but a compromise of less directionality, in a directional speaker could offer more musicallity, and less head banging detail. I think I'll cal Roy Alison, and see what he thinks.

Letitroll98

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Re: Poly Directional Loudspeakers
« Reply #17 on: 23 Apr 2017, 11:21 am »
I think I'll cal Roy Alison, and see what he thinks.

That would be one heck of a phone call.

http://www.audioholics.com/news/a-tribute-to-roy-f.-allison

But I think you're on to something, the Allison 1 or 3 might just be the answer to your search, they always seemed to have their own presentation, neither omni nor direct radiating.  Unfortunately pristine examples are close to unobtainium.

JLM

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Re: Poly Directional Loudspeakers
« Reply #18 on: 23 Apr 2017, 11:30 am »
While at Axpona try looking up Duke LeJeune's Audio Kinesis (not sure he or his speakers are there this year).  One of the concepts he pushes is controlled directivity (like the mighty JBL M2 mastering speakers).  The idea is to minimize sonic energy that hits walls/ceiling/floor and reduce the associated smearing.  Sort of the opposite of poly/omni directionals.  Duke also believes in reducing thermal effects in drivers, so leans towards high efficiency professional drivers.

Back in the 70's I learned to unlike B&O speakers for their dry, constipated, un-involving sound.  Has that changed in 40 years?

Doublej

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Re: Poly Directional Loudspeakers
« Reply #19 on: 23 Apr 2017, 11:42 am »
In describing Allison speakers I have heard the term uniform power response. See the picture below. Unfortunately as Letitroll98 indicated getting a pair in pristine shape is impossible given what the state of the art was in materials for loudspeakers back in the 80s.

Someone should resurrect his design principles and make a few models.

http://img11.hostingpics.net/pics/599524allison1.gif