Thanks Nicolas,
is the original sound then also tuned for improved propagation under water? None of my Memovoxe's ring like the DSA, and some are from the same period.
I am sure that I read some JMC publications talking about this difference between the waves in the air and under water.
Could it be that I am that wrong ?
Is the sound comming out from the two splits at 12 and 6 under the bezel?
Or could it be that my DSA has a problem? It actualy only vibrates and emits a very low buzzing sound.