A DIY Ribbon Speaker of a different Kind

My first post on this thread. (I've only read pages 73 -50)
I found this (@ 4 minutes flat coil winding)

Would magnetic kitchen knife holders work?
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Thank You
 
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My first post on this thread. (I've only read pages 73 -50)
I found this (@ 4 minutes flat coil winding)

Would magnetic kitchen knife holders work?
View attachment 1064056

Thank You
Hi Chris
The original design by M.Deminiere used vertical stacks of neodymium magnets, each
measuring 30mm W x 30mm L x 10mm Thick.....you literally cannot pull a pair of them apart
with fingers, need some kind of jig to pry off the block stack.
You need this kind of force to accelerate the voicecoil/diaphragm, the little kitchen knife holder
would make a weak motor.
The polarity of the two magnet horseshoes also needs to be N/S not N/N.
 
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Hello
I have two more questions about the rubanoid.
1 question
Copper caps are often used in broadband chassis. Now I have dismantled such a chassis and discovered that the copper cap does not conduct electricity to the pole plate. Is this absolutely necessary?
2 question
What is the physical reason that longer membranes of the rubanoid can reproduce lower frequencies than shorter ones?
I would be very happy about replies.
greetings
 
I unfortunately do not understand. higher amplitude why? With normal speaker chassis, the size has no influence on the bass reproduction
That is not correct.
You have to move an amount of air to reach a low frequency and SPL.
A small woofer can go low but with low spl.
With the rubanoide a larger membrane can deliver more SPL or go lower with the same SPL then a smaler membrane.
As for the copper cap's it's not necessary to make it work but some people say it sounds better, so it's up to you.

Rob
 
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Of course, at low frequencies, a large chassis moves more air than a small one at the same stroke. However, this is also the case with medium and high frequencies. Could it be that this process is not linear with respect to the surface?