Insulating a noisy bathtub. How?

I'm installing an acrylic bathtub. The thing is light and easy to work with, but I'm worried that it will sound like a orchestra's timpani drum once installed. What might I do to insulate it? I recently installed a new dishwasher and, as per the suggestion of an appliance shop, I used taped pink insulation instead of the paper-thin sheet that came with the unit. Seems to work well. Could I tuck pink insulation into the underside cavities of the tub to cut down on noise?

Keith

spray foam works too.

Keith,

Yes.

Also, you can fill empty space AND get a little more rigidity with expanding foam. Anything that blocks airflow will block sound too. It needs to block 99.9% for it work well. Taping up the front of your dishwasher was a good idea.

David