There's a pair of these on Ebay http://cgi.ebay.co.uk/ws/eBayISAPI.d...ksid=p3907.m29 How often do these things turn up? Rear view shows one speaker mounted upside down. Does anything need to be done before operating a single ESL 57 long term upside down? It's common sense to check power supply box mounting, but I was thinking about the internal damping cloth, wondering if it would stay where it's meant to......................