Very often, hard plumbing increase sound as the vibration cannot be dissipated.
You can place the pump on a rubber mat if it does not come with rubber feet.
Else, connect to the pipes with a silicon hose. Sample pic from internet.
If its not a new pump, the sound could be coming from worn out bushings or unbalanced impeller.
you need to get a DC pump with SINE technology...... cheapest one is Jebao DCP pump, cheap and good. You can opt for the DCP5000 or 6500 for your 4ft tank which is less then $150