Speedwave DC pumps?

[nrosdal]

i have been running a dc5000 for the better part of a year now and it is quiet as can be. Ther must be an issue with the pump if you are getting a sound at low speed.

when i have mine at full blast i can hear a slight humm but nothing that would travel more then a few feet and then not be audible. Mine is also externally mounted... so sound should be muffled even more if you have it in water. Do you have the base on it so that it is not vibrating against the sump bottom without the rubber feet?