This will blow your mind! well, maybe. at least it nearly blown my mind :)

[Paul.]

This is a fun yet slightly biased and gushing summation of Tesla's works...

http://theoatmeal.com/comics/tesla

 

[Clare Newsome]

And Tesla was played by David Bowie in Christopher Nolan's brilliant film, The Prestige. 'Nuff said....

 

[oldric_naubhoff]

... another example is Tesla's invention. if it wasn't for steel manufacturer's lobbying we would be using wireless electricity long by now...

Erm. What?

http://en.wikipedia.org/wiki/Wireless_energy_transfer

I think he meant the bit about the steel manufacturers lobbying, that isn't mentioned in that Wiki-article.

will not try to prove because I can't. I just heard this opinion one day form long forgotten source. but I don't find it too hard to believe was true since at the break of 19th and 20th century heavy industry was paramount and close connections between business people and politicians are a fact. I just find it quite credible that steel industry didn't want to loose contracts to build thousands of miles long transmission lines and then taking care of its maintenance for many years to come.

 

[Sliced Bread]

It looks fascinating, though do you recon you'd get phase issues having an open source vibrating? (more a question than an opinion)

I'm guessing this is just a concept at this stage. Hopefully it could be installed quite discreatly (assuming it works well).

 

[gbhsi1]

ok. people who know a little my attitude to hi-fi know that I'm no too much fond of box speakers with dynamic drivers. this is not some illogical, emotionally driven, "just because" kind of way hatred. as I was gaining more and more knowledge on how it all works together I came to conclusion that in order to reach my audio nirvana I have to try out other available technologies of sound reproduction. and since speakers are traditionally "the weakest link" I believe the search and research is a worthwhile endeavour. so, I couple of days ago I stumbled upon this thing here:

this rectangular steel frame doesn't look much like a speaker but it is a speaker nonetheless. it resembles nothing that's been invented so far. quite rightly so, it's not working like anything invented so far. I confess that I read the whole part describing how it works and still can't quite comprehend how it actually can reproduce music! I can acknowledge it can make some sounds on its own, but reproduce recorded sounds? but apparently it make quite good job. in fact, if it's as good as it's claimed on the web site this thing may be a bigger step in quality of reproducing music than Western Electric cinema horns from ca. 1930 were over phonograph's sound tube (note that those WE speakers can easily compete with modern designs in terms of SQ)!

there's not much details about its performance know to me yet, but they do attach freq response and phase graph on their web site. I wish they had some more usual speaker performance measurements in order to draw any meaningful conclusions. but this measurement alone inspires some optimism:

freq response from 20 to 20K Hz is simply put flat. and it's flat in good amps' performance terms, not good speakers terms. also there's essentially no phase shift from around 100 Hz to 10K Hz. and even phase shift for the full spectrum is still commendably low compared to most multiway speaker designs. this is always a good sign for perfect spacial resolution - i.e. imaging.

what's the list of strengths? here goes:

- this is a true full range speaker, so no need for any detrimental crossovers networks

- true omnidirectional principle for truer spacial reproduction (no need to spend $$$$$$$ for MBL omins any more)

- no box, so no box colouration nor any box reflections nor any baffle related freq response irregularities

- inherent phase coherence, as noted above an asset for better imaging

- the driver is incomparably stiffer compared to other materials drivers are made of (well it's essentially a steel rod with triangle cross section) so no problems traditionally related with finite driver stiffness like break-up modes or non-linearities at high x-max. this should translate to very good THD performance but let's wait for proofs.

cons? none. well, maybe, for some, the looks. but it's only the prototype so production version may look more WAF friendly.

I encourage you to take a look at the web site (I left the link at the top of the post). and if you don't fancy reading through all that techy flavoured blurb read testimonials at least. very interesting reading indeed...

interesting indeed but the designers will get 0% for aesthetics! unless they incorporate the concept into an existing design....perhaps

 

[oldric_naubhoff]

Think of a Wankel engine rather than one with pistons! It's design is very simple. The triangular vertical omni-directional radiator doesn't rotate but oscillates or pivots around its vertical axis - a fixed magnet provides centring for the radiator at rest & magnetic damping at its resonant frequency. The angular displacement is proportional to input amplitude. The mass of the spindle would need to be almost zero & very stiff so that tortional forces don't cause phase errors from one end of the radiator to the other that would be frequency dependant.

thanks for explanation.

Maybe not a hoax but I can't see it being flat in frequency nor very loud.

that's what I'm affraid too.

I'm also not sure if a 360 degree omni-directional source is a great idea in a room with reflecting surfaces such as walls.

I don't think it's a problem. contrary, I think that's an asset. i have never heard anything bad about MBL's omnis so far (I wish I could listen to what their Radialstrahlers can do one day) and usually they get best sound of the show accolades, wherever they appear.

I think that lobing artefacts are a bigger evil in case of multidriver systems with poor dispersion characteristics. and that's where wall reflections will not contribute anything good.

those Planot speakers seem to work like line source so they should radiate steady wave of sound over the length of the driver into the room. and that means possibly less lobing and definitely less floor and ceiling reflections.

 

[oldric_naubhoff]

It looks fascinating, though do you recon you'd get phase issues having an open source vibrating? (more a question than an opinion)

you mean phase issues, like dipole cancellation, in case of open baffle speakers? the way I understand it there should be no dipole cancellation because there will be no out-of-phase back wave.

I'm guessing this is just a concept at this stage. Hopefully it could be installed quite discreatly (assuming it works well).

yeah, me too. the way it looks now it resembles more some medical lab tool . but I don't think the look can change much from what it is now. the idea is a no enclosure speaker, so it'll probably stay in this frame form. but I think that substituting steel rods for wood would soften the look somehow without loosing too much of rigidity (provided right kind of wood was chosen). or maybe by using some plastic compound you could shape it more into some modern sculpture like form?

 

[busb]

Think of a Wankel engine rather than one with pistons! It's design is very simple. The triangular vertical omni-directional radiator doesn't rotate but oscillates or pivots around its vertical axis - a fixed magnet provides centring for the radiator at rest & magnetic damping at its resonant frequency. The angular displacement is proportional to input amplitude. The mass of the spindle would need to be almost zero & very stiff so that tortional forces don't cause phase errors from one end of the radiator to the other that would be frequency dependant.

thanks for explanation.

Maybe not a hoax but I can't see it being flat in frequency nor very loud.

that's what I'm affraid too.

I'm also not sure if a 360 degree omni-directional source is a great idea in a room with reflecting surfaces such as walls.

I don't think it's a problem. contrary, I think that's an asset. i have never heard anything bad about MBL's omnis so far (I wish I could listen to what their Radialstrahlers can do one day) and usually they get best sound of the show accolades, wherever they appear.

I think that lobing artefacts are a bigger evil in case of multidriver systems with poor dispersion characteristics. and that's where wall reflections will not contribute anything good.

those Planot speakers seem to work like line source so they should radiate steady wave of sound over the length of the driver into the room. and that means possibly less lobing and definitely less floor and ceiling reflections.

Can anyone else remember Sonab speakers? It may have been HFN that slated them ~30yrs ago. They were omnis so the idea has had a chequered history but of course may have been developed into a far more sophisticated product since. Although I sit in the sweetspot between my speakers, I'm lucky in that my Arros have a wide dispersion pattern so others sitting off-axis still get a decent sense of stereo. I presume that omni speakers try to give a stereo image over a much wider area but more defuse than ordinary ones in the sweet-spot would be my guess. I'm not going to go back over the extensive reading since you started this intriguing thread but I did read an opinion that MBL's were bass-light but do take that 3rd handed comment with a bucket of salt!

As for the Planots, bearing design would be crucial. Maybe scrapping the "Home" magnet & suspending the vertical radiator between Berrylium Copper strips as with so-called Taut-band moving-coil meters would provide damping & centre the radiator at rest without stiction but I can't see this radiator working with 10s to 100s of times more mass than an existing tweeter dome. I would speculate that the triangular cross-section would need to be very cerefully shaped (curved) to optimise movement of air & possibly tapered. Although I didn't read the entire thread on DIYaudio that spanned a couple of years as it happens, I got the impression that the inventer failed to take out patents but has disclosed his ideas. The fact that he attacked some respondees is neither here nor there - that aspect being part of most forums as we all know!

PH's link to Tesla reminded me that the world would be a better place if most alpha males were suffocated at birth but human activity is strewn with the wrong people taking the credit & making the money. As for wireless power transfer it's seldom used (Braun electric toothbrushes being an exception!) because it's very inefficient otherwise it would be extensively used - especially in a world that's running out of copper! Car engine running on water anyone?

 

[MajorFubar]

Anyone remember the gas speakers they demo'd on Tomorrow's World in the mid 80s?

 

[busb]

Yes, if you mean:

http://en.wikipedia.org/wiki/Plasma_speaker

 

[oldric_naubhoff]

AFAIK first commercial plasma drivers appeared in 40-ties last century so even in the 80-ties it was no novelty.

only seen tweeters though. can't this technology be implemented for lower frequencies?

 

[steve_1979]

... another example is Tesla's invention. if it wasn't for steel manufacturer's lobbying we would be using wireless electricity long by now...

This is a fun yet slightly biased and gushing summation of Tesla's works...

http://theoatmeal.com/comics/tesla

Thanks for the heads up guys.

I'd already heard of Tesla and knew about some of his work but I'd never realised what an interesting chap he was.

 

[Anonymous]

I am the inventor of the Planot loudspeaker driver; more specifically a new class of acoustic transducers.

I would welcome questions. I will answer then as best as I can.

John

 

[Overdose]

It seems a long time since I first saw the inital write up of your new transducers, 5 years or so, are they yet commercially available?

 

[Anonymous]

See http://www.planotspeaker.com/Planot/Home.html

 

[The_Lhc]

See http://www.planotspeaker.com/Planot/Home.html

Err, yes, that's the same link that the very first post in this thread contained...

 

[busb]

See http://www.planotspeaker.com/Planot/Home.html

Hey OneBox - that's the same link that appeared in the original post. Overdose asks: "It seems a long time since I first saw the inital write up of your new transducers, 5 years or so, are they yet commercially available?"

As the designer/inventor has shown interest in this thread let's hope he updates us.

 

[steve_1979]

I am the inventor of the Planot loudspeaker driver; more specifically a new class of acoustic transducers.

I would welcome questions. I will answer then as best as I can.

John

Hi John and welcome to the forum.

I assume it works by oscillating back and forth rather than rotating?

Is this movement like a vibration moving a small distance (similar to a speaker cone) or does it move a larger distance as it oscillates?

Do you have any idea when it will be for sale, how much it will cost and whrere could I hear it?

Thanks

 

[oldric_naubhoff]

I am the inventor of the Planot loudspeaker driver; more specifically a new class of acoustic transducers.

I would welcome questions. I will answer then as best as I can.

John

hello John and welcome to the forum from me too.

I've found out about your speakers a couple of weeks ago from a thread on DIY forum and decided to spark some interest on this forum as well. very interesting new concept IMO.

I was actually thinking of sending you an e-mail with a few questions but since you've come across our forum I can just as well use the forum as the medium.

first of all; is the research stage over and the prototype has reached its final form?

if so, do you have more comprehensive set of measurements for your speakers? listening impressions are very important thing but measurements may tell many things ears can't always pick up. I would be most interested in CSD and harmonic distortion measurements. also impedance plot would be useful (my amp of choice, which as yet I don't posses , has high output impedance and doesn't bear low impedance speakers well). I would also be very much interested to see "in room" and anechoic lateral response of your speakers; I'd like to confirm that omnidirectional principle will not contribute to creating unwanted resonances.

I also have one question about already available frequency response graph. what was the input power for taking the measurement? was it usual 1W or something less? if it was 1W that would imply low sensitivity of your design, only about 60dB. am I correct?

thanks in advance for your reply. :wave:

 

[Anonymous]

No there are no products available yet. I have been contacted by a number of speaker manufacturers, some not so well known and some very well known. I was contacted by Sony and Philips last year. I was negotiating with Philips for six months but negotiations broke off over contractural issues. I just talked to another manufacturer today; one of kits.

It is a very protracted process of getting a product to market. This is why I am finally courting the do-it-yourself market in hopes of kick-starting the commercialization of my patent.

John

 

[Anonymous]

I and working on a new motor; a potor in my terminology. Potor for "pivoting motor." I am constantly looking for improvements in my designs.

The only data I release is what I publish on my Web site.

The efficiency of the current prototype is not high. Future prototypes will have higher efficiency. The motor is a limiting factor and magnet strength is critical; it is expensive to have custom magnets made. China has been artificially raising the price and availability of the rare earth metals used in exotic magnets.

Specifications and measurements will not mean a whole lot in the scheme of things because different manufactures will implement my diaphragm design, differently. Each engineer has his own idea of the best way of achieving a design goal. So as far as the public is concerned wait for real consumer and professional products to appear before being too concerned over measurements.

The current potor "voice coil" has a 4 ohm rating.

John

 

[oldric_naubhoff]

The efficiency of the current prototype is not high. Future prototypes will have higher efficiency. The motor is a limiting factor and magnet strength is critical; it is expensive to have custom magnets made. China has been artificially raising the price and availability of the rare earth metals used in exotic magnets.

noted.

Specifications and measurements will not mean a whole lot in the scheme of things because different manufactures will implement my diaphragm design, differently. Each engineer has his own idea of the best way of achieving a design goal. So as far as the public is concerned wait for real consumer and professional products to appear before being too concerned over measurements.

still, I think it would be nice to know how your speakers behave with harmonics. just for instance, sometimes you may find out that exciting sounding speakers sound initially great because there's a lot of high frequency harmonic content added. IMO harmonic distortion greatly contributes to listening fatigue. I'm really interested how your speakers fare in this respect. I think I will go DIY route when plans are available for public. but I don't want to make too many "upgrades" in the future if it turns out there's something wrong with the sound. I hope I'll make the right decision and my next speakers will be my last.

The current potor "voice coil" has a 4 ohm rating.

resistive or is there some reactive component to it as well?

thanks for the reply!

 

[Anonymous]

Yes, it occilates

No, I don't have any idea when it will be available as a product but check back at my Web site.

This technology can be implemented at most any price point.

John

 

[steve_1979]

Yes, it occilates

Is it an occilating movement that only turns a small amount of say 1 degree each way or does it move larger amount of maybe 90 degrees?

 

[Anonymous]

About 45 degrees total. But that is a design decision tied to the motor.

John