A DIY Ribbon Speaker of a different Kind

[Drgoodvibe]

Originally Posted by Henjo Edel

As you can see is my voice coil of the underhung type.

From my own experience, there are still a number of points that I want to mention.

Homogeneity of the membrane material.
As you know, paper has to different sides. (drying, rolling, pressing)
Some people experiences a change in sound, and alignment problems with changing humidity.
The reason for this could be non-mirrored membrane halves. By increasing or decreasing humidity the properties of the paper changing antiparallel.

Any deviation in the z-axis of the mounting sides(direction of motion) is the same derogation off center of the voice coil relative to the magnetic field. Here the earlier mentioned “hen’s foot” can do a good job. Centering the voice coil in the Z en X axis. Adjustment in the Y-axis controls the suspension / resonance frequency.

Fill the space in the core of the coil by a material of the same thickness. And wind the wire tight around it, so the forces can be transferred better to the membrane. Consequently, there is the possibility that the coil is moving in the viscosity of the adhesive connection instead of moving the membrane. I think that is the reason why some people don’t reach the 10kHz.

Henjo

Just new to this thread where do I start on this ? could you help, direction please.

[seb4lo]

i'm trying to get in touch with the guy présentation

to build a pair of "monopole" , if the test is ok , i'll may try the Janus70 quite more expensive.....

[AndreP]

Hello Henjo,

wich paper do you have tested, already? Do you have any distortion measurements?

Andre

Originally Posted by Henjo Edel

A few pictures of my prototype.

The sound.
At the moment I have no good reference, but they are easy to listen to, a wall of sound, invisible, small sweet spot.

Suspension.
None, just the paper. But it was not easy to adjust.

Next:
- New coils pour into epoxy resin
- Different kinds of paper, starting with "elefantenhaut"
- Neodimium magnets
- Measurements

Henjo

[ondesx]

Here is my own tangential ribbon...

Sound is immediately loud. It lacks some high frequency range and it haves an uncommon radiation pattern !

Definitely an amazing driver !... It surely deserves more studies and developpment, IMHO !

[koldby]

Hi ondesx.

Please more information!
Looks like a planar diaphgram?
What is there with the radiation pattern?
Why did you change the rubanoid type of diaphgram?

Koldby

[Abelma]

Originally Posted by ondesx

Here is my own tangential ribbon...

Sound is immediately loud. It lacks some high frequency range and it haves an uncommon radiation pattern !

Definitely an amazing driver !... It surely deserves more studies and developpment, IMHO !

Hi, good prototype, congratulation.
If you are looking more high freq response, i believe that it is good to understand the technology. I think that this kind of driver is on the Distribuated Mode Loudspeaker (Or DML) group driver technology. You can google it. Rgds

[Henjo Edel]

Hi Ondesx,

Congratulations with your model of the JanusXX or Rubanoïde.

"It surely deserves more studies and developpment"
You're right about that.

About the high frequency response, did you read my earlier reply?
Be sure de membrane is glued with high stiffness to the motor.
If I recall, doublesided pcb in your case.
Otherwise the motor is moving into the elasticity/viscosity of the glue.

Do you use anykind of equalising?
Is there a big difference in frequency respons I sent in a earlier PM?

Regards,
Henjo

[ondesx]

@ Kolby : please read the posts from Moray James, he gave the Paul Paddock's list of patents, on which the present prototype is based. The radiation is very narrow vertically and broad horizontally with an amazing sound stage image and a beautiful reproduction of voices... The membranes are made of acetate.

@Abelma : yes this is a sort of DML, but I think there are several points to be discussed... I will be very interested to hear Paul himself do comments on this driver... If somebody knows him please ask him to give his lights on it !

@Henjo :Not sure Henjo that I read your post on high frequency behavior, please let me know where is it... You're right my coil is a double-sided pcb. The coil is "sandwiched" by the 2 membranes. The whole is securely glued by double face tape. The point of this driver is the very small movements of the membranes versus the very high output levels... Probably better than 95 dB/W/m ! I have just measure the frequency response for now... Equalizing will be another step and I prefer use it the less possible. Instead of Janus or Rubanoïde I prefer the term "Tangential Ribbon" or remember the author's of this driver, Paul Paddock, a great guy in audio field !...

If one of you guys, have an idea how to wire rapidly rectangular coils of 50 cm high and 4 cm wide, please let me know your technique !... Thanks.

[Abelma]

Originally Posted by ondesx

@ Kolby : please read the posts from Moray James, he gave the Paul Paddock's list of patents, on which the present prototype is based. The radiation is very narrow vertically and broad horizontally with an amazing sound stage image and a beautiful reproduction of voices... The membranes are made of acetate.

@Abelma : yes this is a sort of DML, but I think there are several points to be discussed... I will be very interested to hear Paul himself do comments on this driver... If somebody knows him please ask him to give his lights on it !

@Henjo :Not sure Henjo that I read your post on high frequency behavior, please let me know where is it... You're right my coil is a double-sided pcb. The coil is "sandwiched" by the 2 membranes. The whole is securely glued by double face tape. The point of this driver is the very small movements of the membranes versus the very high output levels... Probably better than 95 dB/W/m ! I have just measure the frequency response for now... Equalizing will be another step and I prefer use it the less possible. Instead of Janus or Rubanoïde I prefer the term "Tangential Ribbon" or remember the author's of this driver, Paul Paddock, a great guy in audio field !...

If one of you guys, have an idea how to wire rapidly rectangular coils of 50 cm high and 4 cm wide, please let me know your technique !... Thanks.

Henjo has a good point saying that the interface between the coil and the mebrane has to be rigid to transmit the high frequency. It has the same effect on the DML loudspeaker. Also about the kind of membrane. Exemple, if the membrane is rigid and elastic, means, not plastic deformation, you will have better high freq response. I am not sure if the weight of the membrane has influence on the high freq, because on the DML technology it doesn't. I understandt that for a pistonic loudspeaker, yes, the weight has influence over the HF response.....but not sure at all for this technology. You may try with an aluminium sheet and see what it happens with the HF response, only for test purposes. I hope it helps my humble opinion.....sorry for my bad english!

[ondesx]

Originally Posted by Abelma

... I understandt that for a pistonic loudspeaker, yes, the weight has influence over the HF response.....but not sure at all for this technology. You may try with an aluminium sheet and see what it happens with the HF response, only for test purposes. I hope it helps my humble opinion.....sorry for my bad english!

Well not really !... The more weight the less level. But the frequency response of the driver remains unchanged...

I know this is hardly understood, but you can do a very simple test : take a driver, measure the frequency response. Then, put it some weight on the protection dome, why not the same, i. e. you double the mass... Measure again. You have the same curve... But with less level !

Now if we speak of the inductance, it's another story.