The best way is to keep it far from your home but if you have somewhere around you make sure miner is in cooler possibly environment. lower ambient temp better.
Also lower clock to 400M and voltage set lovest in the global setting and fan mode in auto silent mode.
This will make it run a bit quieter but dont expect much, best silent is when you turn it off.
People doing own DIY in that matter, you can find some idea  from YT https://www.youtube.com/results?search_query=antminer+soundproof

Here is my version of soundproofing "box"  https://vimeo.com/244755225
 
But lets stick to the topic of Blissh firmware