NZXT Kraken X63 Review - Noise levels - Sound pressure readings

Acoustic Performance

With a certified dBA meter, we measure how many DBAs originate from the PC. It's slightly subjective as there is always noise in the background, from the streets, from the HD, PSU fan, etc so this is by a mile or two, not a precise measurement. You could only achieve objective measurement in a sound test chamber. Take this measurement as an indication, not a precise measurement, please.

The human hearing system has different sensitivities at different frequencies. This means that the perception of noise is not at all equal at every frequency. Noise with significant measured levels (in dB) at high or low frequencies will not be as annoying as it would be when its energy is concentrated in the middle frequencies. In other words, the measured noise levels in dB will not reflect the actual human perception of the loudness of the noise. That's why we measure the dBA level. A specific circuit is added to the sound level meter to correct its reading in regard to this concept. This reading is the noise level in dBA. The letter A is added to indicate the correction that was made in the measurement. Frequencies below 1kHz and above 6kHz are attenuated, whereas frequencies between 1kHz and 6kHz are amplified by the A weighting.

In idle you cannot hear the fans. Once we put the processor at 100% load with several full wPrime runs. Noise pressure is still not an issue. The cooler is silent to normal when it comes to noise levels. Despite the low noise levels, we can hear the pump a tiny bit though, which is something we have not heard with other Kraken models.

So that makes one wonder; what happens when we overclock? Well, DBa levels rise only once we pass 1.30V voltage to the processor and overclock. So at default clocks, this is a good cooler in terms of acoustics however fans kick in relatively fast now that CAM is not controlling them any more. Our advice, connect them to the motherboard FAN connector, assign 600 RPM (fixed) and you're good to go completely silent. The CPU certainly has enough cooling capacity left to do that.