Custom Made Drivers by (Lowther Modification Support Group)

[ghemml]

Some of the work and craftmanship from the Lowther Modification Group's members

 

[ghemml]

more of their works

 

[ghemml]

cont...

 

[ghemml]

Cont....

 

[jotom750]

Hi G.
It's fantastic to see the inventiveness of the ideas you are using to improve the drivers. I myself have been considering modifications to another make of paper drivers to attempt to control a very fierce break up mode. The step up in of the order of nearly 8db, and almost vertical in rise. Rather than reduce the crossover frequency or use high order slopes I would wonder if modifications to the paper cone profile to stiffen it may help. Rather like the ribs shown on this picture. (Which you may recognise). I would attempt this by adding ribs as I could not press them in. I imagine that they would be slightly larger than the ones shown here. If there any FR graphs of before and after, that would be great. Many thanks for any assistance.

 

[ghemml]

Hi G.
It's fantastic to see the inventiveness of the ideas you are using to improve the drivers. I myself have been considering modifications to another make of paper drivers to attempt to control a very fierce break up mode. The step up in of the order of nearly 8db, and almost vertical in rise. Rather than reduce the crossover frequency or use high order slopes I would wonder if modifications to the paper cone profile to stiffen it may help. Rather like the ribs shown on this picture. (Which you may recognise). I would attempt this by adding ribs as I could not press them in. I imagine that they would be slightly larger than the ones shown here. If there any FR graphs of before and after, that would be great. Many thanks for any assistance.

To be honest with you, in fullrange application all those cone breakup can be quite nonsense as many people claimed online. We have members making use of 130gsm paper commonly used on, shellac hardening, low gauss motor and they are pretty decent to listen to. You can check the members' work.

Over hardening of paper can be a negative effect on the midrange shout, paper need some softness to absorb some of the freq without them getting to over amplified on the midrange. We also experiment on whizzer cone with different weightage paper, normally we tend to use paper on the whizzer cone much lighter than the main cone, around 80gsm to 100gsm

But we can't just focus paper hardening, the motor is an important factor. And from the experience in the group, we commonly agree anything about 1.6Tesla on the magnet gap can be too overwhelming and making the driver very forward. Even a 1.3T we find it maximum performance vs acoustic performance vs percentage of the VC in the flux. Then designing of Field Coil (Which is not really complicate to do)

We also have quite a bit of discussion on types of winding technique and wire, CCA(Copper Clad Alu) wires, Copper wire, self bonding, which this will lead to another discussion on adhesive for example 3M Nitrile glue, CA glue, epoxy bonding available from wire industries like Ultimeg.

Do join the group, we have lots of technical information in it.

 

[Boden]

Hello Ghemmi,

What kind of felted or fibred paper have you used in your last 4 pictures, and where do you source that material?

 

[ghemml]

If I am not wrong it should be mulberry paper, re-enforced with shellac and different material. It is done by our member "Бранко Кашиковић" from Serbia.
He also uses papyrus paper in his work as well.

You can check out his work

https://www.facebook.com/groups/493360037882723/permalink/660685501150175/
https://www.facebook.com/groups/493360037882723/permalink/855766411642082/
https://www.facebook.com/groups/493360037882723/permalink/603384953546897/
https://www.facebook.com/groups/493360037882723/permalink/668151280403597/

And his beautifully made custom drivers

https://www.facebook.com/groups/493360037882723/permalink/588640078354718/

 

[Boden]

Unfortunately I do not have access to these Fb pages.

 

[ghemml]

Unfortunately I do not have access to these Fb pages.

You still can click on them to view the photos, even without FB account. The group is set to public, so anyone with or without account can view the contents

 

[ghemml]

Unfortunately I do not have access to these Fb pages.

I attached in my reply, so u can see it closer

 

[Boden]

Thanks a lot, Ghemmi.
Looks like a press-mold. Is the raw material heated in the cone mold-press?

 

[ghemml]

It is mixture of reprocess material and off the shelf paper material. The heat press does the trick as I seen member in the group reprocess paper using heat source

 

[ghemml]

Lowther DX2 rebuild

 

[ghemml]

AER rebuild.

https://www.facebook.com/video.php?v=768619151894929

 

[Guerilla]

AER is another brand?
Did any of you use bamboo for cones as I think JVC did in better midi system speakers?
How about balsa wood for support ribs? Its light, and rather stiff I think.
Cheers!

 

[ghemml]

AER has been around for quite a while

https://aer-loudspeakers.com/

 

[Guerilla]

Very Lowther inspired or very different?
Cheers!

 

[Ivo]

Similar, the membrane and whizzer configuration are the same, but materials are different. Sounds similar, but different. I thought they sounded cleaner and more real 20 years ago. Don't know how they have evolved since, or compare to current Lowther drivers.

 

[ghemml]

The new Lowther cones sound very different from their old version and of course different from AER.

The new Lowther cones are much thinner and the have redesigned the suspension system