I don’t much trust dB measurements as there aren’t rigorous standards for measurement distance and other test conditions. 45HL tried to justify the Noctua upgrade:
But there are some questions about the test results that never got answered, particularly around CFM:
The real thing one needs to know isn’t dB/RPM, it is dB/CFM. How much noise is generated in order to move a certain amount of hot air out of the case.
I don’t question the Noctua upgrade for the full build; that needs to be done because of the stupid 2-pin wiring setup. I’m less convinced for custom builds with motherboards that will take DC fans. Although, PWM fans probably give you finer control over the fan curve than DC fans.
If your noise floor is already high I guess it’s not an issue. I thought from the LPs and turntable you might be more sensitive to these acoustics.