My 2ct
Hi,
I am watching this flame fest and finally had the urge to respond.
And about physics, when a rotating mass, the mass is pulled in, in accelerates. Like sitting on a office chair and pulling your legs in while rotating. The mass of the planot is centered and very near the pivot point. The problem is not accelerating, but stopping it!
Been thinking about this design a long time and came up with a theory why it works. Tested my hypotheses and it seems to be correct. The planot is not relaying on piston action by pushing air, but by creating small turbulence to create under pressure. Exactly the same what makes (paper) air planes fly. Or this contraption using the magnus effect
And about that YouTube clip:
1) No homing magnet. In my own experiments this makes a HUGE difference. It will focus the sound.
2) No centering support on top. The wobbling prevents MF en LF output. This problem caused me to stop experimenting.
My own experience with the design is that it has beautiful mid's and high's. With only 1 speaker build, i and my friend could hear depth. It baffled us completely. And yes, it is painfully inefficient. But this can also be because where using a UcD 100 watt amp (at full volume) and the single voicecoil had a impedance of 16 ohm.
Hi,
I am watching this flame fest and finally had the urge to respond.
According to this NXT speakers will not make HF. Some brands are using plaster walls. That is a lot of mass! There are more means to generate HF.
And about physics, when a rotating mass, the mass is pulled in, in accelerates. Like sitting on a office chair and pulling your legs in while rotating. The mass of the planot is centered and very near the pivot point. The problem is not accelerating, but stopping it!
Been thinking about this design a long time and came up with a theory why it works. Tested my hypotheses and it seems to be correct. The planot is not relaying on piston action by pushing air, but by creating small turbulence to create under pressure. Exactly the same what makes (paper) air planes fly. Or this contraption using the magnus effect
And about that YouTube clip:
1) No homing magnet. In my own experiments this makes a HUGE difference. It will focus the sound.
2) No centering support on top. The wobbling prevents MF en LF output. This problem caused me to stop experimenting.
My own experience with the design is that it has beautiful mid's and high's. With only 1 speaker build, i and my friend could hear depth. It baffled us completely. And yes, it is painfully inefficient. But this can also be because where using a UcD 100 watt amp (at full volume) and the single voicecoil had a impedance of 16 ohm.
Jelle Schrijver: hello!
Jelle:
Good to hear from you again! Still playing the bass?
You are right about the homing magnet. Using the Homing magnets together with a analyzer is critical. The mass and the "straight-ness" of the diaphragm is critical. Just about everything is critical. My current prototype uses two voice coils who's combined impedance is 4.5 Ohms and the whole moving mass is very low and the whole structure is very stiff. Also you must be sure to remove all sources of mechanical noise.
Jelle, send me an e-mail at: info@planotspeaker.com
I have a deal for you.
John
Jelle:
Good to hear from you again! Still playing the bass?
You are right about the homing magnet. Using the Homing magnets together with a analyzer is critical. The mass and the "straight-ness" of the diaphragm is critical. Just about everything is critical. My current prototype uses two voice coils who's combined impedance is 4.5 Ohms and the whole moving mass is very low and the whole structure is very stiff. Also you must be sure to remove all sources of mechanical noise.
Jelle, send me an e-mail at: info@planotspeaker.com
I have a deal for you.
John
Create the Future Design Contest
Please follow the link below to vote for Planot for the "Create the Future Design Contest" sponsored by Tech Briefs, COMSOL, HP and others. Pleas share with friends.
Voting is simple.
Open this link...
Planot: Boxless, Full Range, Omnidirectional Speaker :: Create the Future Design Contest
Scroll down to where it says... WANT TO VOTE FOR THIS ENTRY?
Register (it's free and only takes 2 minutes) then log on and vote.
Thanks,
John
Please follow the link below to vote for Planot for the "Create the Future Design Contest" sponsored by Tech Briefs, COMSOL, HP and others. Pleas share with friends.
Voting is simple.
Open this link...
Planot: Boxless, Full Range, Omnidirectional Speaker :: Create the Future Design Contest
Scroll down to where it says... WANT TO VOTE FOR THIS ENTRY?
Register (it's free and only takes 2 minutes) then log on and vote.
Thanks,
John
Sure...
Ever seen a CSD plot of a NXT speaker?
Ever wondered why NXTs are limited to "lifestyle" and computers speakers and never made it to up there with the best performing so called High-End speakers (subjective and/or objective)?
Ever heard NXTs and preferred their HF compared to a "good" dome tweeter?
There are always some basic physics "rules" involved that one has to follow in order to make a good sounding (and measuring) sound emitting device, Planot is not one of them.
Last edited:
Physics Upheld
For those nay-sayers trotting out their love of physics to dispel the Planot concept, the sound is real, the sound is accurate, the technology is in evolution, and nobody is claiming this will reproduce bass like an Altec 515 in an A7 cabinet. The Planot actually fills the room with the sense of sound as well as actual sound. It is very hard to describe the sound properties just as it is hard to reconcile the traditional application of physics. I have my opinion about where it could be a stunning player in the audio world but John may not have the same vision. I will not step on his approach to perfecting this transducer because he is doing quite nicely.
For those nay-sayers trotting out their love of physics to dispel the Planot concept, the sound is real, the sound is accurate, the technology is in evolution, and nobody is claiming this will reproduce bass like an Altec 515 in an A7 cabinet. The Planot actually fills the room with the sense of sound as well as actual sound. It is very hard to describe the sound properties just as it is hard to reconcile the traditional application of physics. I have my opinion about where it could be a stunning player in the audio world but John may not have the same vision. I will not step on his approach to perfecting this transducer because he is doing quite nicely.
Hi,
Accurate ? Like you've measured them ?
Yes, its very hard to describe the sound of someone completely
kidding themselves due to completely and utterly positive bias.
Bass ? They don't it, in any shape or form, they cannot.
rgds, sreten.
Wow! a DIY forum participant thinks more of measurements and graphs than actual sound? More importantly, I have no intent on using the Planot in my system nor do I have any interest in promoting their commercial success; but don't expostulate from across the pond that it must be rubbish because it is out of the norm. It is not rubbish I have listened to them. As for most middle aged DIYers the operative question is, can your ears even hear above 9k? Statistically you are rare if you can hear over 9k once you're passed 50. I have my hearing tested yearly and still am right at 12k before rapid drop off. The new drive motors for the Planot are beautifully made and I look forward to listening to them again soon.
He (and I, for that matter) think more of measurements and graphs (real ones, not the nonsense posted on the planot site) than testimonials by an unknown person, especially when claims counter to basic physics are advanced and no basic data are offered. John is singularly unwilling to do a public demo, so that's all we have to go off of.
If he gets some measurements from a competent and independent practitioner, AND puts them out in public, good, bad, or ugly, that would go a long way.
Hi,
I think more of measurements than pontificating nonsense.
If they don't measure well they are not accurate EOS.
FWIW at 56 my hearing dies a death above 13 KHz.
Not that it has much to do with the Planot nonsense.
rgds, sreten.
Last edited:
A voice coil suspended in a magnetic field attached to almost anything, a hanging wall mirror, a door or an empty plastic water bottle can produce "sound", is this "out of the norm" enough for you?
"Out of the norm" is not a bad thing, on the contrary, but still, you need measurements to know how accurate the produced sound is.
Last edited:
Measurements and listening...
Floyd Toole stated in, "Sound Reproduction, Loudspeakers and Rooms, Elsevier/Focal Press, in chapter 2;
"The author's experience suggests that the performance target for almost all consumer loudspeakers is a more-or-less flat axial frequency response."
Geddes, whom Toole quotes extensively in his book, agrees with Toole on the importance of frequency response as Geddes has seen in his experiments with listeners. But Geddes goes on to say that equally important is a lack of reflections and diffraction from a loudspeaker enclosure. Then Geddes says that these two factors are the only important ones when a loudspeaker is played at normal listening levels.
These are some of the design goals of the Planot speaker.
John
Floyd Toole stated in, "Sound Reproduction, Loudspeakers and Rooms, Elsevier/Focal Press, in chapter 2;
"The author's experience suggests that the performance target for almost all consumer loudspeakers is a more-or-less flat axial frequency response."
Geddes, whom Toole quotes extensively in his book, agrees with Toole on the importance of frequency response as Geddes has seen in his experiments with listeners. But Geddes goes on to say that equally important is a lack of reflections and diffraction from a loudspeaker enclosure. Then Geddes says that these two factors are the only important ones when a loudspeaker is played at normal listening levels.
These are some of the design goals of the Planot speaker.
John
- Status
- Not open for further replies.