Telefunken RB46 Speakers (5403 "Sound Columns")

[Wagner]

Looking for someone who can and does repair these "non-standard" vintage German types (or who is willing to advise)

Sold as stand alones as the RB46, labelled "5403" if they were supplied with a receiver or radio

I have a pair I just re-capped, very impressive little boxes.............BUT, I have an issue with woofer cone resonance and it's bad, ruins the speakers

Using warble test tones I have identified the main problem as being between 63-80Hz; any "off the shelf" suggestions? Can't hurt anything

Fairly large oval shaped woofer, VC alignment is good and the spider appears flat and firm

Have done/checked all I can do, even treated the pleated surround edges with a little PVA (these speakers were poorly stored I think)

Very very nice sound after the re-cap, mids to highs

These are worth repairing, so my question is: does anyone here work on these types or know someone who does?

https://www.youtube.com/watch?v=5ZoRZWT2Kp4

http://www.lajazz.us/audio/R/Telefunken-RB46/RB46_003.jpg

[Hoerninger]

More pictures:
http://www.hifido.co.jp/KW/G0201/E/7200-50/C09-27799-18569-00/

These speakers remind me of my first speaker project about 1967.
The tweeter and the bigger oval speaker are made by Isophon. (he third speaker I can't identify)
These big oval speakers have a high QTS which makes them unsuitable for closed box or bassreflex designs. Telefunken made holes in the back. Perhaps it is adviced to use a back with bigger holes or to use some damping behind the speaker.
These ovals sound quite nice in an open baffle design.
___________
Peter

[Wagner]

These big oval speakers have a high QTS which makes them unsuitable for closed box or bassreflex designs. Telefunken made holes in the back. Perhaps it is adviced to use a back with bigger holes or to use some damping behind the speaker.
These ovals sound quite nice in an open baffle design.
___________
Peter

I know they sound good, that is why I am hoping to have the woofers repaired

I tried the PVA on the edges and damping in the boxes prior to the re-cap

I am running/working on them now with the baffle board removed from the cabinet (I have the complete systems, Telefunken's original cabinets as shown in your link's pictures and the video I provided)

The detail present with the parts that do work properly is pretty darn good now; these will make some very fine Jazz speakers IF I can get the woofers to handle some bass notes!

I am fighting the urge to apply something, either to the spider or cone, but am trying to be patient and wise (once you do it, it's done) Hard to discern if I am fighting a "too stiff" or "not stiff enough" problem with the spider or a cone that is just so dehydrated it's resonance frequency is way up there..........either way

When I move the cone by hand it feels firm (the spider) and springs right back into place when the cone is released) For what that's worth

When I first acquired these they were unlistenable; playing them gently and running a 30Hz tone through them for a long period has made them somewhat usable (they are fantastic for voice/talk radio) but they still can't handle music with any bass content like sustained notes with a long decay (think Diana Krall stuff)

On things like Sinatra/Riddle (uncompressed, original mixes/mastering) they sound very good (parts of it anyway)