Quiet is subjective, many of these fans are well within the error tolerance of their specs &/or my gear.
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On the other hand, other factors such as motor noise or blade chop come from the fans as well. Which make them more audible to some, and thus "louder" even though, in terms of Sound Pressure, they're on line with another product.
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BeQuiet, Noctua, Noiseblocker, & Delta fans are the most expensive on the market and available in most areas. Three of those manufacturers are worthwhile, while the other can only be considered if their 2nd generation being is used.
Hint, their name starts with an N and they like to use the color brown.
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Got a few more fans added to the 2nd post, gonna do more in the morning after some painkillers for my hands and rest.