My new batch 5 S5 is 'new' (definitely NOT used) and so far everything works-'knocks on wood'.
it looks about 2-3db less loud at ~71-73dB at one feet (in comparison with ear busting batch 1), but maybe this is more wishful thinking than anything else.

I will use a new cheaper mod tonight-we'll see if it works. ~$20-24/miner.
Lowes in my area is completely out of pan M4-0.7 35-45mm screws. had to buy hex.
I surmise that S5 modders scooped them all up, LOL.

There's not much you can do out there with fans unless you use two of those Noctua IPPC 3000 models. They have beeb bought up everywhere, assuming S5 owner's are buying them up by the dozens. Any fan(s) that have a high enough CFM
to properly cool the miner will always be too loud.

But I'm still curious as to what your plans are?

My final two S5 shipped Friday and would have arrived Monday, but somehow, the UPS driver screwed up the delivery and a different driver completed Tuesday -- bummer on the whole day delay, lost some good WestHash payout !!!

Have received two each by USPS EMS, Fedex, UPS, and all would have been "two day" delivery (excluding Sunday and the UPS SNAFU), lowest shipping cost was EMS via DHgate back in January.  The latest two (with S3 push fans) are setup side by side on the floor of my coolest room running 312.5MHz and temps 47/42 and 43/40 (top temp was 59 Vs 52 at 350MHz over a 2-1/2 hr check out). That first consistently runs by far the highest temp and fan speed of my three pair and makes me consider the heat sink paste mod described earlier** (currently 2760 Vs 2160 rpm) -- it also had pre-damaged Phillips head screws by whatever gorilla installed and warped the plastic side panels (since loosened).  Am expecting to give Silverstone FHP141 pull fans a try this coming weekend.

Thanks again Bitmain for the timely ordering assistance (Janet/Tim) and quick turnaround of the order -- here's looking forward to learning about the next generation!

**https://bt.irlbtc.com/view/902305.msg10926267#msg10926267

I thought I had a 15 AMP but as it turns out I have a 30 AMP and can confirm that 3 S5s will run on this. I am not overclocking anymore. All at 350 Frequency. Purring along. New 20 AMP breaker goes in today so I can buy more

http://www.frozencpu.com/products/13819/fan-901/Akasa_140mm_x_25mm_VIPER_PWM_Fan_w_Hydro_Dynamic_Bearings_AK-FN063.html

Will two of these 110CFM fans in a push/pull configuration be enough to cool at 350M?

Came today 2 S5. Version 1.91 and 1.7. In version 1.7 does not work one of the blades

http://joxi.ru/v297DonsXyg7rG

Hope that you are right!

EDIT: LOL it is an April Fools joke. I puked in my mouth when I read the announcement.

Fuckers!

I will make sure. Thanks for the heads up!

True, cooling is critical, and so, if need be, underclock is necessary.  Fan noise is major to me since the miners share my living space!  Adding an exhaust fan makes it easier for the intake fan to do its job, doesn't have to be noisier than the single.  Very interested to see how the Silverstone works out on the exhaust (two S3 fans on an S5 are much louder than one, though still easily quieter than S5 stock).