Another interesting Ebay item

[Nuuk]

These look interesting. I'm particularly intrigued by those mid-range drivers. Does anybody know exactly what they are?

 

[Mr Evil]

The weird looking midranges have diffraction gratings on them, I believe. I see them on horn speakers sometimes, for controlling dispersion.

 

[Magnetar]

Sawafuji Dynapleats

 

[Nuuk]

Sawafuji Dynapleats

So are they some kind of ribbon?

 

[GuyPanico]

What I think is funny is that Sawafuji sounds japanese, that manual looks german, and they're made in Ireland

 

[HeatMiser]

So are they some kind of ribbon?

They are weird drivers, each of the "bumps" has a voice coil embedded in it and rows of bar magnets in back drive the thing. They are dipolar though. I've heard them called ribbons but personally I think that stretches the definition pretty far.

ldsg.snippets.org has some info about them but I'm not sure where exactly one would look, and I'm having trouble getting to the site at the moment.

 

[Nuuk]

Interesting! I wish that I was closer to go and have a listen.

 

[HeatMiser]

I don't actually have any, but there was a little speaker building place near here several years ago that was putting them into various systems. They also did crazy car stuff for fun, and at one point they had a little Nissan Z car with the whole back end converted into a sub cabinet and horizontal arrays of (I think) 6 of those Dynapleats across each door.