silent system in wooden box- 2 80mm or one 92/120 intake fan?

[Bentrold]

I am planning to modifying an old Aopen hq8 tower by removing all steel and plasic on the outside and replace it with 14mm solid Ash wood on the sides and 34 mm solid ash/ veneer on MDF plate on the front and a hinged cover in front of the drives and the reset button (to keep them out of reach and to minimize the noise from the drives). I am going to install an aluminum door on the left side of the case to improve acces to inside and I want to cover the inside with cork or maybe magic fleece from Noise Control.( Any recommendations?
Since I am pretty much going to seal the case I will need some good silent fans: front intake 2 x 80 mm Pabst 26,5 cfm/19 db(A) or 92 mm Pabst 35,9 cfm/23 db(A). Exhaust: an 80mm or a 92 mm Pabst in the top, but channeling the air to the back of the case and a 60mm or 80 pabst near the CPU/agp slot.

How big a difference is there between 2 x 19 db(A) and 23 db(A)?

Anybody know if it is possible to fit an 80mm fan on Thermalright sk-6?
Is it worth channeling air from the outside to the HSF with some kind of duct (PVC drain pipe) ?


- Bentrold

 

[Spike]

How big a difference is there between 2 x 19 db(A) and 23 db(A)?

Remember that as far as sound intensity goes, it doubles every 3 db, so 23 would be twice as intense as 19. I am trying to find a site now that proves that, but so far no can do. At least I learned one thing here at school

-Spike

 

[clarkmo]

I have a 92mm fan and duct going from the side of my case to my sk6. The duct is a TacoBell xlarge cup trimmed to fit. The advantage to this duct is the gradual lessening of the diameter from fan size to sk6 size. The results are a 4 degree range from idle to full use. Once, I believe the temp increased 5 degrees centigrade from idle temp. This is extremely stable. If you can keep the flow going thru your duct than yes, it is worth it.

 

[Dim]

I believe what is doubled with a 3dB increase is the power. As far as perception of loudness goes, a 3 dB increase is not much. If I reacll correctly (and I may not - most of you weren't born when I studied this) perceived doubling of sound intensity correlates with a 10dB increase.

 

[Ausone]

Actually, the total noise from two 19dB fans is 22dB. So the difference between your two options is 1dB.

If you put a 80mm fan on a 60mm HS via adapter, you'll need more CFM to get the same cooling capacity as a 60mm fan in comparison. I don't it's worth effort & cost to put a 80mm fan on SK-6. I'd rather get a really quiet 60mm fan or undervolt one.