I have an emperor 400 and 280. The tubes that come with these are pretty long, so long I had to cut it cause the intake hit the bottom when I first installed it. (55g) But i do believe you can buy extention tubes but I'm not 100% sure. I have the 400 intake close to the bottom and the 280 higher up around the middle of the tank. The 280's performance is not affected cause of where the intake is at. When you first get the filters going they are a little noisy for a couple of weeks, but after you "break them in" they really become quiet. Now all I hear is the trickle of the water going into the tank. The motors and impellers are pretty quiet. My tank is right next to my ear by the couch and it does not affect me watching tv or talking on the phone etc. I have 3 filters altogether, the 2 emperors and a Fluval 305 canister and all of them are very quiet. The bio wheel itself does not make any noise or propell the water into the tank to cause any additional noise. It just flows through them and trickles out to the tank. They also do a nice job with agitating the surface and water flow on top of the water. My 400 is pretty new and I have had the 280 for about 5 years now. I definately recommend them but can't compare them to the AC70 cause I have never used that brand of filter. I bought mine for about $55 at my LFS so don't go to petsmart cause they are listed at $74.99. Hope this helps you out, let me know if you have any more questions.