AudioKinesis Planetarium Beta
Geophysicist -- Fri, 04/03/2009 - 10:15
I recently took possession of a pair of Duke Lejeune's Planetarium Betas, which consist of a pair of main speakers with two 12" woofers, mounted front and back, and a pair of 1" compression, waveguide-loaded tweeters, also mounted front and back. The idea behind the design is to produce a "controlled-pattern bipolar configuration". The mains are specifically designed to roll off at, by my estimate, 65 Hz or so. Below that, music is handled by what I consider to be the truly innovative part of the system, the SWARM. The SWARM is a set of 4 small subwoofer units, each with an 11" X 11" footprint, and utilizing a ported 8" woofer (tuned to 25 Hz). The subs are driven by a very flexible 1000 watt amp. The idea behind the SWARM is to place them at locations at varying distances from room boundaries, with each sub having its own room response, and thereby producing a much smoother overall room response when output from all four is summed. In my own field of expertise (geophysics), this is known as minimizing constructive interference. Does it work? Boy, does it ever. I had thought that my previous speakers (SoundLab A-1PX) were relatively impervious to room effects. They are, actually, but not nearly to the degree that I had thought. I am now enjoying the best bass, both in quality and quantity, that I've ever heard anytime, anywhere, in nearly 40 years of audio experience. Those looking to extend their bass response (Quad, Maggie, and high quality monitor speaker owners spring to mind) should definitely give the SWARM, which apparently is sold as a standalone system too, some serious thought.
I'm still trying to get a firm handle on the overall sound of the Planetarium Betas. The process is complicated by the fact that I have a brand new amp as well (Atma-Sphere S-30 Mk III...did I mention that the speakers are 96 dB efficient?), which is breaking in. I've never seen any piece of electronics that changes its sound so drastically almost by the hour as the break in proceeds. Regardless, I'll mention two very distinctive areas of superiority that are evident even now. The soundstage is extraordinarily wide and deep. I know many audiophiles who do not place a particularly high priority on this characteristic, but I'm most definitely not one. It is very, very striking. Dynamic capability, as might be expected from what's technically a horn-loaded system, is outstanding. Now, I've never been a big fan of horns. Regardless of the protests of horn enthusiasts, I could always hear that 'horny character'. The waveguide in the Planetarium beta produces none, at least that I can detect at this stage. So, we have the benefits of a horn without the downside. I love it.
In this world of 'yet another variation on the box stuffed with OEM drivers', I love seeing the innovation, particularly when it works SO well. And even more particularly, when I'm the beneficiary!
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That sounds like an interesting loudspeaker. The Atma-Sphere amplifiers are known for their soundstaging, and it's amazing what a lower-powered amplifier can do driving highly sensitive speakers.
I hope I get to hear the Planetarium Beta at a hi-fi show (perhaps the Rocky Mountain Audio Fest?).
I've been following Duke's work on solving the problem of mating subs to "stats for several years, and thanks for tipping me off on the SWARM. It is amazing how the soundstaging improves as one gets the deep bass right. You get much more of a sense of the hall from the plane of the speakers to the listening position.
Like you, I've never been a big fan of horns but they have been quietly getting much better reducing coloration. The latest version of the Classic Audio Reproductions loudspeaker mated to Atma-Sphere electronics at CES sounded glorious. I'm looking forward to hearing the Planetarium Betas---know of any sets in the Bay Area?
Robert and Jim,
I recently posted my review of the Planetarium Betas on Audio Asylum:
http://www.audioasylum.com/audio/speakers/messages/28/283487.html
And here are some system photos if you care to have a look:
http://forum.audiogon.com/cgi-bin/fr.pl?vaslt&1242404267&openmine&zzCurriemt11&4&5#Curriemt11
The review will make it clear that I think these are extraordinary speakers in many respects. It's unfortunate that they will probably never be reviewed by any of the mags. They deserve to be far better known.
As for RMAF, I'm not sure. Duke has had a display in the past, though.
> know of any sets in the Bay Area?
I don't. Best thing would be to contact Duke and ask, I guess. And, of course, if you're ever in the Houston area...
Looks good - but it's still a cone-in-box for the midrange. That would not make it much different.....
Hi JR-1,
If you're speaking of the drivers themselves being relatively conventional, you're correct. However, given that the set of drivers is duplicated on the rear of the speakers to produce a bipolar radiation pattern, I would say that it's quite different from the run of the mill "cone-in-box". This is what produces the extraordinary soundfield that I personally find so appealing - and more realistic - than any conventional box speaker I've ever auditioned.
If it's bipolar in the midrange then this is a failed idea - in all due respect. Mirage was the only co. to try this. It didn't work as audiophiles everywhere rejected the sound...........
It is bipolar from about 65 Hz on up, and I assure you that it is in no way a 'failed idea'. It was designed to mimic the soundfield of the SoundLabs electrostatics. Are these also failed ideas? Since the last speakers that I owned were the SoundLabs A-1PXs, I can say with absolute certainty that they succeeded, and then some.
With all due respect, I suggest that you do not make assumptions on the characteristics of gear that you have never heard.
SoundLabs are not bipolar !! Mirage was the only one - not a good sign to start with. That it was rejected by audiophiles only made it worse......
I realize that SoundLabs are not bipolar. They are dipolar, hence the use of the term "mimic the soundfield" of those speakers. I'm sorry to see that you cannot seem to understand that these are quite different in both design and execution from the Mirages. Oh, and by the way, Definitive would be interested to know that their highly successful line of bipolar speakers doesn't really exist, as only Mirage has produced them.
I can see that you are one of those who are quite sure of his own position in spite of the fact that 1) you have no experience with the specific piece of gear, and 2) an extremely experienced audiophile is telling you differently. All I can say is, listen for yourself – with an open mind - if you get the opportunity.
I won't bother to answer you further. I've said everything that needs to be said.
I'm open-minded...but I owned the Mirage M-1 in 1989 and sold it shortly thereafter. Maybe the Planetariums work better, but it still looks bad when only one (or two) co. in the history of audio made bipolar loudspeakers. *Dipolar* seems better - hence its loyal following.....
Well obviously I'm kinda late to this party...
JR-1, I appreciate your voicing your concern, and if you see this please feel free to respond.
In 2008 one of my bipolars received a Golden Ear Award from Robert E. Greene, which implies that maybe I'm doing something right.
The configuration I use is called a "controlled-pattern offset bipole", and when set up correcty it has some interesting attributes, including: Combines early-arrival sound characteristics of a narrow-pattern speaker with the reverberant field characteristics of a wide-pattern speaker; wide sweet spot and good tonal balance throughout the room; no baffle-step falloff in the lower midrange region; reduced magnitude of the floor-bounce dip; and smoother in-room bass.
You can read more about what I'm doing at this link:
http://www.audiocircle.com/index.php?topic=56877.0
By the way, I prefer manufacturing speakers that are well off the beaten path. What would I be adding to the choices audiophiles have if I simply do another "me too" product?
To Robert Harley, I did not display at RMAF 2009 because I was busy working on some prosound projects (in prosound, speakers are "tools of the trade" rather than "expensive toys" so sales hold up better in a poor economy). I plan to show at RMAF 2010.
Duke LeJeune
AudioKinesis
> In 2008 one of my bipolars received a Golden Ear Award from Robert E. Greene, which implies that maybe I'm doing something right.
Well, after just under a year of owning these speakers, I can certainly confirm that there's no 'maybe' about it. The Planetarium Betas are, on balance, the most satisfying speakers I've ever owned. This is no 'me too' product, and thank goodness for that. I would urge any who are interested in a truly innovative yet reasonably priced (whatever that means) speaker to attend RMAF and have a listen. I hope to be there, Duke. Would really like to meet you after all of these years.