Now I see the problem.
You currently have
30 80mm screamers, so you beleive (based on current experience) that fans are louder than drives.
Yes, this is usually true, but it doesn't have to be.
It is easy to make air cooling much less noisy than drives, in fact water cooling is often louder than smart air cooling these days. (The pump on foam usually makes more noise than 2-3 x 120 ultra low speed, vibration isolated fans, if you use the right fans.)
An mCubed T-balancer will give a fan full current to get it spinning, than drop it back to the lowest RPM it is capable of still working at (RPM is monitored by the T-balancer). Get the right fans and this is
very slow. If the temps go above a set level it speeds up the fans based on a temp/speed curve you create in the software.
Seriously, many over at SPCR say the idle & seek noise from their single suspended 3.5 drive is by far the loudest part of their air cooled system. Think about that, it's a whole different world of "quiet", and it can be had with just air.
At one stage I built a drive silencing box for around 10 drives out of 3/4" wood, and tons of accoustic foam. The box had a single burried fan blowing/sucking air through a maze of sound baffling. The end result- the drives stayed nice and cool, I coudn't hear the fan,
but the hard drives were still far too noisy for me. I've never used it.
P180 which could be made quieter than the h/drive box standing next to it.