During fall 2016 I received a pair of Sonab OA12 with original speaker elements and in need of reparation. The first part was changing the membranes which was ordered from Ebay ”One pair of 6.25″ foam surrounds for Sonab spkrs. eg SW 7 etc.See list.”.
After changing the membranes the speaker obviously performed better but still had a scraping sound from the left speaker when played quite loud. However as of now this is not a problem as they don’t need to perform at this high sound level but in the future replacement speaker elements will be installed.
The next problem was the old DIN speaker connectors. New terminals was installed using a 3D-printed adaptor. The STL-file can be downloaded here Sonab OA-12.