12" rvk fan - quiet please!

Today I got a real bargain on a hardly used 12" RVK A1 fan (1300m3/h)
It came with 5 metres of electrical flex and a plug (which is usually an extra expense)
and it has a mounting bracket attached (normally £11 extra).

But it's NOISY....!

I was looking at GORILLA BOXES and I was told that they're VERY EFFECTIVE, VERY LOG LASTING and VERY QUIET.
Unfortunately they're also VERY EXPENSIVE!
And, to my untrained eye, they appear to be little more than a box constructed from MDF and pumped full of insulating foam.

Has anyone made their own DIY gorilla box?
Or maybe implemented noise reduction in another way?

All suggestions greatly appreciated.

It is all down to the quality of the insulation foam inside. If you are handy, i would make my own. Go buy the foam from an audio supplier, do some googling on the best materials for sound proofing rooms. It will be expensive, but you wont need much more than a few square meters of it. Don't forget to use rubber dampeners. Noise comes from both air waves and vibrations from the fan. Good luck!

Thanks
That's my project for December.

I have insulated ducts for music rooms since i played drums, I use rockwool insulation in wood and gypsum board layers. the rockwool comes in many grades, the best i used is pinkish very soft doesnt make much dust when handled. the box design is what's most important, part of the sound waves bounce and others get absorbed so you need to make solid barriers inside the box lined with insulation. you also need to make it aerodynamic and large enough. it is not an easy task to get it right without diminishing fan efficiency but it is definitely feasible. every layer of solid cover (wood or gypsum) needs to be totally sealed from the sides with solid mastic applied to edges. any small hole in a wall results in diminishing most of the soundproofing effect. the insulation must not be pressed together but kept loose. I prefer to attach the box to a solid wall and the fan seperately to the wall using rubber lining around it. If you want to further lower the noise, buy a fan controller, it almost removes the noise to just set it on below max. however it is said to shorten the lifetime of the fan, and to my experience, it seems true...

wooden box fan all the way shift far more air an is the quietest on the market

http://www.ebay.co.uk/itm/like/160538984686?hlpht=true&ops=true&viphx=1&lpid=95&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=95&ff19=0

RVK fans aren't made to be boxed up it create extra heat, sell it an buy the above no cutting corners! unless you want a fire in your grow room

Thanks, Zem - Very interesting.

Machead - I cannot afford a wooden box fan yet....
In another 10 weeks maybe....

http://www.ebay.co.uk/itm/350765537802?var=620112647356&ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Maybe these could help solve the problem?
Two times the above amount (£120) would be enough to cover the wall that shares a neighbour.