One advantage of the S9 over previous designs is that it makes less noise and less heat so your cooling cost is lower than the S7. R4 is still the best of them all but I'm not sure Bitmain still has anymore as at now.
The S9 I have had good luck with but I would not consider it a quiet miner. You must be downclocking it a way's to get it even close to quiet. And also most at this point use server PSU's on them and they are not quiet for most part either. These are not problems for me with my mining area but a S7/S9 in some places might be to loud. There are some who have made boxes or other things to help soundproof and that can make a difference.
But if quiet is what your looking for there are some older generation stuff that are much more quiet. Or wait and hope to see more of R4. But hard to predict what is happening there so would not build a "mining center" waiting on R4's.
But OP you need to go into so much more detail's and you really are going to have to do a lot of research to. We really cannot set up your mining area , but can help on some aspect's. But again need a lot more info. I suggest reading some other threads on this or look at picture thread for idea's. Come back with what you want, budget, etc. And you will find much better help.
