I have a nice wittner which seems to slows down and lose precision around and below 60 bpm afer a while. It seems however that above 100 bpm works fine.
How could I be sure that it works correctly (i.e. the beat is steady and even)?
How could I fix it in case it is not perfect?
Can it be fixed?
Has anyone had or noticed the same problem with mechanical metronomes?
N.B the metronome is new from the shop and it never fell or sustained any damage since I had it (about a month).