Thanks all, some good and interesting suggestions here. I think I will start with the simplest approach and see if I can get a long range stereo bluetooth transmitter powerful enough to do the job - and see about the cost of a pair of active speakers to receive and amplify the bluetooth signal...
I've got a pair of old passive speakers, but was more or less reconciled to needing to buy new, active, ones to receive a wifi or bluetooth signal, since obviously the amplification will have to be done at the speaker end.
Hmm thanks, that rather fits with what someone at Richer Sounds thought. But he felt Bluetooth would not work over 12m and through a brick wall. That’s why I was wondering if I could somehow co-opt the wi fi in the house instead.
Maybe it will just have to be cables then. But let’s see if...
I expect this has come up before but I'm having trouble finding an answer. I'm looking for a device to transmit the signal from my existing old stereo system to remote speakers in another room about 12m away. Basically I'm trying to avoid running wires over such a distance as it would be messy...