A friend of mine measured a few stock boxes between 41 and 43 Db. Keep in mind Db is a logarithmic scale so one notch higher is
a lot louder than the difference from one notch lower. Also realize that your Hard Drive might be making a lot of your Xbox's Noise. The stock HDD on my V1.0 was nearly 3 times louder than the fan :lol: Most version 1s also have GPU fans that sometimes rattle and make
a lot of noise. I was lucky and mine is wisper quiet. swaping out the HDD alone and my Xbox is silent (stock fan and all).
No idea what the CFM (no good way to measure it) but I'd make an educated guess that it typically runs somewhere between 25 and 35CFM.
Just upgrading to an 80mm alone should theoretically reduce the noise level (larger fans dont have to turn as fast to product the same airflow).
If you want lots of Quiet:
-get a HDD with a low noise rating
-get a quiet 80mm fan with a low noise rating (Vantec, Papst or Panaflow, etc.)
-rubber grommet mount your HDD
-get some noise deadening material and line the non vented areas around the hard drive and fan
As for the 12V fan mod the sound of the air flow alone is friggin loud, honestly there's no good reason to do it in my opinion.
a lotthe space bar is our friend