What pump model do you currently have?

I think the Matrix came with that filter but I want to make sure. That is normally a fairly reliable pump so there must be something about your installation that is causing issues with the pump. Can you post a picture of your setup? Is there anything unusual in your setup?

I need a quite motor, so I can leave my windows open at night.
This assumes you actually need to run your pool at night. Given most pools can get away with less than 4 hours of run time per day, you could just choose a run time not at night. But also a two speed would really help the noise factor because you can run on low speed most of the time.