What weight setting on the SPL meter should be used to assess noise levels in an AV rack room?

Using C Weighted settings on an SPL (Sound Pressure Level) meter is appropriate for assessing noise levels in an AV rack room because this weighting emphasizes lower frequencies, which are commonly present in the operational sounds of AV equipment. These low-frequency sounds can significantly impact the perceived noise within confined spaces like rack rooms.

C Weighting is particularly relevant for evaluating environmental sound levels, including those that may come from fans, cooling systems, and other equipment that generate a continuous hum or noise. Moreover, C Weighted measurements align more closely with how humans perceive sound intensity in environments where low-frequency noise is prominent.

On the other hand, A Weighted settings are more suitable for measuring sounds in areas where higher frequencies are more relevant to human hearing, while D Weighted is less commonly used and focuses on very low frequencies, often not applicable for standard AV rack evaluations. Z Weighted provides a flat response across all frequencies but may not effectively highlight the critical low-frequency noise typically generated by AV equipment in a rack environment. Thus, using C Weighted settings ensures an accurate representation of the noise impact in that specific setting.