Noisy Overflow Need Advice

[longhorn_20m]

Well, I just finished all the plumbing on the Oceanic 180 and filled it up and turned on my return pump.

Here are the specs:

Oceanic 180 RR
Two overflows in each corner
Durso in each overflow
Mag 9.5 Return pump (I suspect with the height, it is pushing a little over 700GPH, thus ~4x going through my sump)

I was amazed at how loud it was. It isn't from the Durso pipe, as they're pretty silent, just hear a slight hum as air pass through it. The noise is from the sump and as a result of the water entering it. What are some techniques to reduce this?

I also attached some pictures.

I also have another question related to the return pump. I've previously owned Mag 5 and Mag 7 pumps and they each had a base attached. The Mag 9.5 I received (brand new from Drs F & S) doesn't have a base. Is it good to have it sitting directly on the bottom of the glass sump? It seems from the vibrations and how it is positioned, it moves itself around slightly and when just right increases the noise as it vibrates off the glass. How do others use the Mag 9.5? Do you put something under it to provide a buffer?