If you want to make the box more quiet, you need to prevent more of the air from reaching the reeds. To do that for the bass side all you need to do is twist (screw in) the two front buttons a little so that they don't open as much.

John

Yup...

sounds like someone has a screw loose here. Bruce has a better idea. Take heed!!

Thanks for your help. learn more each time I ask a question.

.... Ed

Screwing the button in or out will work on some accordions but not all. Some have a spacer on the button's threads that sets the travel. So on those the spacer would need to be modified. On accordions without the spacer turning the button will tend to loosen the threads and you could end up with the button screwing itself closed. Best in all cases to consult with the maker.