A DIY Ribbon Speaker of a different Kind

*LOLOL* No chit! But his earlier observation aligns well with our current...oh, 'ell. near constant view of our dolts. But us Dems are hopeful....wish us all luck. ;)

Understand illness, although mine is the 'sick 'n tired' version...

Jealous of your 3D capability....I wish I could wish things into existence. *G*

Although I'd like to 'do' them into titanium....*L*

Feel better...so we can 'see' what you're 'hearing'...

Cheers, mate. *S*
 
Signs of life...

*L* Old topics never die....they just vague away... ;)

Rubinoids have a fascination, being the dipole/omni sort of person I is. There was a fellow in EU that had made a huge version, some 4~5' tall!. I believe it was called an Airfoil, although I can't seem to get the Google to dredge it up.

MHO, there has to be a physical limit as to how large the radiating elements can be to be efficient unless the magnets start to rival subs in their size. I may be wrong, but I could be right....to quote the refrain from a song on an unrelated subject. *L*

Anyway....Happy Monday....although that sometimes seems an oxymoron... ;)
 
Hi there
I also build a rubanoid, but only with a front membrane. With Femm I was able to find out a lot, but unfortunately not everything I want to know. I would prefer to use disc-shaped magnets. Does anyone know how I can simulate this with Femm?
Thank you in advance. Also for the many information in general!
 
Ah....
Impact Airfoil 5.2 loudspeaker system | Stereophile.com

Don't know if they're still in production....but they are BIG.....

peril, don't know how disc magnets would work, but since they're placed between bars....and if Femm could cope with (IMHO) any 'lobe-ing' of the fields created...

I'm thinking of a 'wavy field', mimicking a beaded chain as on an old lamp with a chain switch....and I appreciate the 'perils' (no pun intended) of prototyping anything...

That, and I'm only slightly familiar with dipole rubanoides....'single-faced' ones' are new to this mortal...*S*

...and y'all have EU sources that are 'mysterious' to 'stateside' mortals.... ;)
 
I would prefer to use disc-shaped magnets. Does anyone know how I can simulate this with Femm?

I think you would need a different, 3D capable program to model this. FEMM says it's "for solving 2D planar and axisymmetric problems".

Sometimes it's easier to build a simple prototype and measure the result than it is to accurately model a system.

From the FEMM FAQ:
Finite Element Method Magnetics: FAQ
"20 Is there a 3D version of FEMM?
No. For intrinsically 3D magnetostatic problems, I sometimes use Radia."
 
DIY-ing into the Void of Happy Happenstance....

bandsei, that was my thought about those magnets....it'd make sense that they'd be polarized in that axis. First reaction was they're out of old hard drives. SOP for DIY...I'm guilty as well. *G*

If that was the case, they'd be strong but one would need a bunch of them. Placed between bars, you'd get a lot of 'field strength', but it's a 'guesstimate' whether or not the field would be 'consistent' in shape. *?*head scratch*

Ergo, my comment on 'lobe-ing'; perhaps if that occurred there may be a hidden positive result. The space between the magnet assemblies in relation to the driven coil plane may benefit in being adjustable to explore that potential...

The Radia link seems to be aimed at a crowd that 'if it's not SOTA/'bleeding edge' research related, don't bother us...IMHO....

I'd explore making a 'test rig' where one could 'swap out' magnet structures with a 'given' radiator structure. But that would only be perhaps useful for a
'conventional' rubanoide design....

For a Manger DIY unit....I've no clue as to an approach, as I've not been drawn to copy one.

I have my own Quixotic Quest...;)
 
An intriguing thought....

...perhaps....

Most rubanoides I've seen (not heard) tend to be 'full range' drivers...except for, of course, 'deep bass' into subwoofers....

Now, this has struck me as a common occurrence with planar type drivers.

Magnaplanars have a separate HF 'area', if not a 'stand-alone' driver....and the bulk of 'FR' speakers have similar 'HF issues'....

I wonder if a 'Small+Large' rubanoide arrangement would yield more 'even' response overall? I've found that the case with my Walsh drivers; it was noted in comments on the original Ohms units. The current Ohm speakers seem to address this with separate tweeters within the 'basket' atop the main drivers.

Hence, the 'toe-in'/Left & Right speaker designations their pairs come in...

I'm trying to get around and over that....

"One Driver to Rule Them All", borrowing and paraphrasing TLOTR 'hardware' . *L*

Any thoughts on that? Just curious....
 
Shared album - Albert Schweitzer - Google Photos

According to the theory of bending wave propagation, a tough elastic material is ideal.

On the drawing you can see an experiment that everyone can do with a sheet of paper. The semicircular membrane makes a lateral movement at the end of the membrane.
The membrane attached to the center towards the end makes no visible lateral movement. I think this is advantageous.
Maybe someone disagrees?
Unfortunately I have to stop the Ruba project because I am forced to demolish my workshop. I illegally built 12 square meters 13 years ago. now the authority has discovered this. ****
 
3D Printed Rubanoid anyone? Also ironless -

Finally had the time this evening to... - Sparrow Legs Speaker Design | Facebook

Rubanoid.jpg