Is it about as loud as a typical air pump, or a bit louder due to it being larger?
Can you post a pic of the tank?
It's probably about the same noise level as the Tetra 10 & Tetra 40 as long as it's on a towel. Without a towel, the vibration gets transmitted through the feet and the air line. I was using the 10, it was okay for the bubble curtains, but it couldn't handle 2 sponge filters.
The tank is the one in my avatar, but it's been transformed about a week ago. The center piece is gone (I felt it was too bulky for the tank), the blue gravel has been exchanged for pool filter sand and live plants are now planted on the sides. The fish seem to enjoy the sand & more open spaces.