What is the most quiet return pumps?

[BlueAbyss]

Originally Posted by sphelps

I would assume the quiet ones are also synchronous. Correct me if I'm wrong but I believe this simply means the frequency of the AC motor is consistent and therefore always turns at the same speed. This would likely be consistent with any magnetically driven pump. I'm fairly confident that these two pumps are identical, meaning the same motor and impeller.

I think synchronous refers to the rotor (impeller) rotating at the same speed as the rotating magnetic field in the coils, which I assume is where the electronics come in.

It's good to know that this pump is not quiet. It is efficient though...