I have a very simple question after having put the sound generator together: How can I be that the sound is so low, that I almost can’t hear it? I have looked at all the possible thing I could think of but everything seems to be fine. Except for the fact that the sound level aren’t fitted for humans.

Everything else seems to be working fine!

Can you help me please?

Best regards Mikkel

Most likely an assembly error or bad battery is at cause.
If you can link to SHARP and HI-RES picture of both component and solderside, we can take a look at your assembly.