I have classic looking DAB radios in my Herald and Vitesse, Both using the dealer option housing and speaker on top of the tunnel, the Vitesse recently started giving intermittent sound which has progressed to no sound. I tested the radio on the kitchen table with a spare speaker I had from on old Peugeot I used to have, no sound at all, the radio display and function is all normal. Peugeot speaker had 3.5 ohms across it.
Today I measured the resistance on the old speaker as the supplier said it should be around 4 ohms. The speaker has a dead short across the connections.
I had a spare original one In the shed so I measured that, 3.2 ohms, swapped them over and it works in the Herald, but the Vitesse radio has to go back to the supplier as It looks like the speaker short has killed the output.
So I wondered, how is the speaker constructed and where does it get the resistance, Is there a coil in there?.
Steve