Can anybody help me to find out about a high end brand of stereo speakers

[Ruphus]

Hi all,

a while ago my sister gave me a pair of high end speakers. They must be about twenty years old. Pritty nice stuff, think to have not heard such good sounding boxes anywhere. Looks like they were build by a German brand which might not exist anymore, can´t find any info where ever I try.

On the back there is written "KLANGRÄUME, Phonarch / 12.83 / 003 PW" on it.

I would love to find out what I could do for theses boxes. For example the bass cones are brown meanwhile and I guess they have been black once, so probably there could be things to do for care or improvement.

BTW, as I am about care. These speakers are feeded by a Luxman RX-103 Receiver whichs pots do crackle. Luxman itself seems to think it not necessary to respond to my questions. Any tip on this issue thus would be appreciated very much as well.

Thanks a lot for any advice or info.

Ruphus