1. You can build some noise barrier.
2. Downclock S7 to freg 550 , put fan to 37% to get 3000 rpm.
S5 fan to 30% to get 2700 rpm
or
3.
Click to enlargebelow only works on 1-2 miners:
1. I put S7 on a shelf rack (bottom shelf), then put couch pillows on three sides and on top shelf in an igloo fashion.
2. around exhaust, I put large poster cardboards (since I have them) to create a sort of labyrinth (like an incomplete skewed "T") so exhaust bounces off a couple of times before exiting. i had to experiment with boards to find the optimal angles.
3. This resulted in just 60-61 dB at 1m distance even on automatic fans (4320/4200rpm)
cheers