Hi,
So lets get this right. You doing the DIY community a favour by charging
each person $500 for some blueprints, construction notes and parts.
This for design where you have chosen to ignore the real physics as and
when you choose in case physics indicate your "theories" might not work.
From your arguments the driver has no phase. Movement in
either direction would causes positive pressure (allegedly*).
That is a half wave rectifier.
(* Except it doesn't, that is clear from simple inspection,
no bass is produced at low frequencies, the examples of
subwoofers in the patent / on the site simply won't work.)
Moreover the dynamics of driving a rod from each end
the inevitable resonant nodes of the rod are ignored.
What else has been ignored is hard to say with the obfuscation.
For $500 I'd expect a lot more than vaporware, certainly not
something based on a premises that are clearly wrong, and
that comes with "promises" that are impossible to make.
rgds, sreten.
Its believable but hardly HiFi, in any sense.
So lets get this right. You doing the DIY community a favour by charging
each person $500 for some blueprints, construction notes and parts.
This for design where you have chosen to ignore the real physics as and
when you choose in case physics indicate your "theories" might not work.
From your arguments the driver has no phase. Movement in
either direction would causes positive pressure (allegedly*).
That is a half wave rectifier.
(* Except it doesn't, that is clear from simple inspection,
no bass is produced at low frequencies, the examples of
subwoofers in the patent / on the site simply won't work.)
Moreover the dynamics of driving a rod from each end
the inevitable resonant nodes of the rod are ignored.
What else has been ignored is hard to say with the obfuscation.
For $500 I'd expect a lot more than vaporware, certainly not
something based on a premises that are clearly wrong, and
that comes with "promises" that are impossible to make.
rgds, sreten.
An externally hosted image should be here but it was not working when we last tested it.
Its believable but hardly HiFi, in any sense.
Thanks for your interest.
The plot you have shown is from a prototype built by someone else, not me. That prototype does not have the top of the diaphragm secured and there is no homing/dampening mechanism. I have stated before, here and in other places, that both of these are critical for acceptable performance, let alone good performance. A plot for frequency and phase is on my Web site.
Moreover the dynamics of driving a rod from each end
the inevitable resonant nodes of the rod are ignored.
My prototypes are all driven only at one end.
From your arguments the driver has no phase.
No, did not say it had no phase.
Planot
The plot you have shown is from a prototype built by someone else, not me. That prototype does not have the top of the diaphragm secured and there is no homing/dampening mechanism. I have stated before, here and in other places, that both of these are critical for acceptable performance, let alone good performance. A plot for frequency and phase is on my Web site.
Moreover the dynamics of driving a rod from each end
the inevitable resonant nodes of the rod are ignored.
My prototypes are all driven only at one end.
From your arguments the driver has no phase.
No, did not say it had no phase.
Planot
Has anybody heard them...
Yes, I have quoted some of the people who have heard them on my Web site.
I have been invited to give a public demo to the Chicago Audio Society. The public is welcomed. See details on my Web site.
John
Yes, I have quoted some of the people who have heard them on my Web site.
I have been invited to give a public demo to the Chicago Audio Society. The public is welcomed. See details on my Web site.
John
I have had people who were interested but never showed up for one reason or another. I would entertain having a representative from a print magazine or an owner of a high-end audio shop come and listen. I had been begging for years for people to come and listen.
Is anyone out there listening?
John
Could this 'speaker' be a kind of omnidirectional balanced mode transducer?
I like this outstanding explanation of the conventional type, by LineSource, a contributor on this forum..
"To achieve a balanced response of a bending wave transducer, the modal
density - the number of modes in a given frequency interval - has to be
much higher in a good bending wave transducer than in most musical
instruments.
A musical instrument has typically a low number of high Q resonances in
a given frequency interval, while in a bending wave tranducer we ask for
a high number of resonances having also a lower Q.
Depending on the Q of the resonances and their distribution over frequency,
it is widely held as a rule of thumb, that a bending wave transducer
should have at least 10 modes per octave, to make a balanced response
possible. A mode is a vibrational pattern spreaded along the membrane
area of the transducer. Every mode is associated to a certain resonant
frequency af the system.
Instead of trying to avoid resonance, the design of a bending wave
transducer is about increasing the number of modes to make the device
behave "statistical" by modal overlap:
Once the modal overlap is high enough, there is no resonant behavior
audible.
I explain a bending wave transducer sometimes to myself as some kind of
"universal" musical instrument. If the modal density and further acoustical
properties are chosen well, it is able to "emulate" existing musical instruments:
An observed vibrational mode of our crash cymbal e.g. or a violin to be reproduced,
falls into a frequency range, where a whole set of modes of the bending
transducer is excited. If built well, the characteristic spectral power
distribution of the instrument can be approximated very closely.
To achieve this, it is not necessary for the vibrational modes itself to
look similar to those of the instrument to be reproduced. What matters is -
like for conventional loudspeakers too - a balanced frequency response of
the radiated sound pressure and the acoustic output power".
__________________
I like this outstanding explanation of the conventional type, by LineSource, a contributor on this forum..
"To achieve a balanced response of a bending wave transducer, the modal
density - the number of modes in a given frequency interval - has to be
much higher in a good bending wave transducer than in most musical
instruments.
A musical instrument has typically a low number of high Q resonances in
a given frequency interval, while in a bending wave tranducer we ask for
a high number of resonances having also a lower Q.
Depending on the Q of the resonances and their distribution over frequency,
it is widely held as a rule of thumb, that a bending wave transducer
should have at least 10 modes per octave, to make a balanced response
possible. A mode is a vibrational pattern spreaded along the membrane
area of the transducer. Every mode is associated to a certain resonant
frequency af the system.
Instead of trying to avoid resonance, the design of a bending wave
transducer is about increasing the number of modes to make the device
behave "statistical" by modal overlap:
Once the modal overlap is high enough, there is no resonant behavior
audible.
I explain a bending wave transducer sometimes to myself as some kind of
"universal" musical instrument. If the modal density and further acoustical
properties are chosen well, it is able to "emulate" existing musical instruments:
An observed vibrational mode of our crash cymbal e.g. or a violin to be reproduced,
falls into a frequency range, where a whole set of modes of the bending
transducer is excited. If built well, the characteristic spectral power
distribution of the instrument can be approximated very closely.
To achieve this, it is not necessary for the vibrational modes itself to
look similar to those of the instrument to be reproduced. What matters is -
like for conventional loudspeakers too - a balanced frequency response of
the radiated sound pressure and the acoustic output power".
__________________
Last edited:
Hi,
I not saying what you said, just saying what you said must imply.
Clockwise or anticlockwise rotation does not matter according
to your description hence the driver has no correct phase
connection, that is plainly obvious.
I said it has no phase (according to your description) and in
reality it doesn't either in any particular sense because it
cannot produce bass of any sort.
The lack of a homing / damping mechanism is pure obfuscation.
The fundamental operating principle does not work as described
rgds, sreten.
I do not believe it is a balanced mode transducer.
One point to consider is that a motor, with an open structure, itself produces audible output but of a "very" limited frequency response. A diaphragm that has more flex produces significantly lower sound level and reduced frequency response than P3 or P4. Making the diaphragm stiffer helps but until you have a 3 dimensional diaphragm of my design the frequency and sound levels are limited. Dampening is critical for optimum performance in frequency and loudness and distortion.
John
Hi,
Pretty much what I expected given your contempt for basic physics.
Your "speaker" doesn't work according to the way you claim it does,
it cannot do what you say it does, academic integrity seems for you
not an issue, and you can't engage in a discussion about what it
actually does because your too busy claiming its "fantastic".
I for one am not going to cough up $500 for what I believe is
probably more of the same that is on the website and next to
no useful real technical information.
It has all the hallmarks of pure "vaporware", from the glowing
(impossible) testimonials, to loads of "technical" illustrations
and claims that are all not remotely backed by one shred
of apparent understanding of real acoustic engineering.
There is nothing stopping an individual making anything based
on a patent for personal use, and its quite unethical that your
saying that is not true, and want $500 for probably nothing.
It is not the case "it works" because you say it does, it is the
case it doesn't work for basic physics reasons stated by many,
and refusing to to enter a discussion is simply the "long con".
If any of it was true, including the "response curve" posted
on the website we wouldn't even be here, the patent would
have been bought out years ago by an eager conglomerate.
It hasn't and it is clear why. The IPRs are worth nothing.
rgds, sreten.
Any Engineer worth his salt, asked to look at it for his company,
should report back quickly to his bosses that it is pure fantasy.
Kirk : What about trying to do this ? ........ whatever
Scotty : Ye canna break the laws of physics, Captain.
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Despite Planot's response to my question, it IS a bending mode transducer.
I would guess that he got the idea from seeing people turn computer hard drives into poor loudspeakers on the net.............probably Youtube.
When voice coils are placed in a strong magnetic field, they will move and vibrate.
In this case the Planot unit does exactly what a hard drive does : the voice coil vibrates and those vibrations are transfered in to the bearing shaft and eventuallly to the ''rod''. The rod rotates in sympathy to the strength of the signal(just like a hard drive....again) and the ''homing magnets'' keep it from moving too far.
The white nylon(?)base in the photos is used to dampen further movement and excitation of bending waves, trying to concentrate the vibrations to the rod only.
Are you suggesting that a bending wave transducer is a 'conventional type'? I thought the conventional type would be the electro-magnetic cone transducer.
jan
An omnidirectional bending wave transducer as opposed to a more conventional monopole or dipole type bending wave transducer. Here is a list of manufacturers of various types, also supplied by LineArray..
some examples of manufacturers of bending wave loudspeakers:
"Transducers based on wave propagation on thin foil
Manger Schallwandler
Airfoil Loud Speakers
Conical shaped membrane driven at the apex
Ohm Speakers
German Physiks - High End Technology Loudspeaker Manufactur - DDD Driver - Home
Flexurally (more or less) rigid flat panels
TERRA-SP3000 of Teragaki-Labo?????????????????TERRA???????????
Welcome to GÖBEL - Revolutionary Bending Wave Technology
NXT Sound - Home
http://futuremusic.com/blog/2007/12/...hile-speakers/
Special case
MBL - Unique High End Audio
I assume bending here is only intended for the lowest mode,
higher order modes seem to be circumvented by using smaller
membranes for higher frequencies. So these may not be
"bending wave speakers" in the same way as the examples
mentioned above."
__________________
Last edited:
Hi,
Its not a BMR (balanced mode radiator) or an NXT DMR (distributed mode
radiator). BMR's are a combination of pistonic radiation and DM radiation.
Both are horrible things to design if you are not armed with a powerful
computer and accurate real time finite element simulation of the driver.
The way the 3 dimensional diaphragm is driven it cannot produce any bass.
It is also impossible for it to move as one surface above a critical frequency.
Below that frequency output is very low and is theoretically zero.
Its anybodies guess what happens when the 3D diaphragm enters its
region of torsional twisting modes, and of course damping of the
diaphragm and its internal damping would make a lot of difference.
However one thing for sure is there is still no reasonable mechanism
for it to produce something resembling a flat accurate response.
Its nearly 5 years on from the inception of the "design" and its
pretty clear it has gone nowhere fast, because it fundamentally
does not do what is claimed, it is not a pressure transducer.
What this image actually represents is anybodies guess.
rgds, sreten.
Its not a BMR (balanced mode radiator) or an NXT DMR (distributed mode
radiator). BMR's are a combination of pistonic radiation and DM radiation.
Both are horrible things to design if you are not armed with a powerful
computer and accurate real time finite element simulation of the driver.
The way the 3 dimensional diaphragm is driven it cannot produce any bass.
It is also impossible for it to move as one surface above a critical frequency.
Below that frequency output is very low and is theoretically zero.
Its anybodies guess what happens when the 3D diaphragm enters its
region of torsional twisting modes, and of course damping of the
diaphragm and its internal damping would make a lot of difference.
However one thing for sure is there is still no reasonable mechanism
for it to produce something resembling a flat accurate response.
Its nearly 5 years on from the inception of the "design" and its
pretty clear it has gone nowhere fast, because it fundamentally
does not do what is claimed, it is not a pressure transducer.
An externally hosted image should be here but it was not working when we last tested it.
What this image actually represents is anybodies guess.
rgds, sreten.
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