I wanted to go into ASIC mining a couple of months ago, had a Antminer S9 in my basket and filled down my information but then I saw a video on YouTube about the noise they produce. Never thought it would be that loud, so did some tests in my study room with a device that makes an equal amount of noise and found it too loud so I canceled the order. The Avalon seems a little bit more quiet, but still too loud for the apartment I live in. The noise reducing you did seems to be going to the right direction for me. But I just hope that they will produce quieter machines in the future, so an average person can also enjoy ASIC mining.
It will certainly make your avalons quiter, but not enough to sleep in the same room. You can for example put this into your living room instead, with the idea I and philip described above. The problem is always the fan, but it is required to cool these machines down. Thus, your idea of a quiet ASIC machine is not feasible because it makes the miner much expensive, see r4 from bitmain, it has almost the hashrate as avalon but 2 or more times expensive. Water-cooled machines would make it much more expensive.
My walls aren't thick enough to block most of the noise. When I watch TV in the living room I still hear it quite loud in my bedroom. I guess I got to wait till water cooling is affordable. Because water cooled mining machines like the R4 don't seem to be worth it at this moment, unless you have free electricity.