Aquaclear vs Whisper

I was wondering about the noise produced by the Aquaclear
filters. I have several Whispers, and they are all quiet. I
have one Aquaclear Mini, and it tends to buzz. Is it just a
lemon? Also when I put CO2 into the Whisper it makes a
racket each time a bubble hits the impeller. I no longer use
that method. Does the Aquclear do the same?  If so is there
any way around it? I do like the rinsable sponge instead of
the throw away filters....