Another question is why does the pump run so badly with Automatic Frequency Settings?

Hi Guys Just got my Aquastream XT Ultra and I am having a problem with the frequency setting. If I set the Aquastream to "Automatic frequency settings", it spends about 5 minutes trying to find its optimal frequency before settling at about 80Hz. at which it vibrates a lot and is very loud. After a bit of trial and error I found its best setting (for noise) seems to be 58Hz. My questions are: 1. Is this normal? 2. Can I damage the pump by manually setting the frequency? Ive updated the Firmware ...