My Fluval canisters are very quiet. The eheims are even more so but it's almost unnoticable either way. The E400's...and I have a LOT of them running...are quiet for HOB units but they all make a splashing sound from the waterfall returns. The AC's can be quiet but its a bit hit or miss...this is due to the impeller magnet clearance.
IMO your best bet for quiet is a good canister in an enclosed stand.
IMO your best bet for quiet is a good canister in an enclosed stand.

