Hello,
my Quattro 48/10,000 feels twice as loud as my refrigerator, a humming noise is clearly audible. It is not possible to stay in the same room for long periods. Without load only switched on.
On the other hand, my Phönix 12/1200 is completely silent as long as the fan does not switch on.
1 Why is that?
2 Which Phönix / MultiPlus / Quattro are noiseless?
I would also be happy to hear about your experiences.
Best wishes