NTi Audio
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Frequently Asked Questions

Room Noise Criterion (RNC) Measurement with XL2 analyzer




The XL2 Audio and Acoustic Analyzer is the first handheld instrument providing on-site results of the Room Noise Criterion (RNC).

Room Noise Criterion measurements are recommend if the ambient noise contains modulated or fluctuating noise components in the low frequency range, such as generated by heating and venting systems (HVAC). Fluctuating low frequency noise is annoying to the persons in the room, thus leads to an annoyance penalty when measuring noise curves.

XL2 Analyzer averages Spectrum every 100ms
The handheld XL2 measures the octave-band sound pressure level to determine the applicable room noise criterion (RNC) curve in accordance with ANSI 12.2-2008. The instrument averages the acoustic spectrum every 100 ms and monitors for any low frequency fluctuation during the measurements. If the measurement results exceed the limits for non-fluctuations then the LEQ levels below 300 Hz are automatically “penalized”.

Acoustical Consultants receive handheld RNC Measurement
“In the past consultant's derive RNC results based on a complex and iterative external spreadsheet process. The calculating power of the XL2 Analyzer offers a new generation of time saving and efficient RNC measurement. The RNC function is part of the overall NTi Audio XL2 solution for acquiring and deriving noise curves automatically and internally with the XL2 Analyzer. The new XL2 noise curve capability, including the RNC measurement, will be one of the most valuable advanced functions available to any professional acoustical consultant" comments Thomas E. Mintner, President of NTI Americas Inc.


The RNC Noise Curve functionality is part of the Spectral Limits Option and offered with firmware 2.60 or higher. Download the latest XL2 firmware V2.60 for free at XL2 Support website.

Read more about the XL2 Acoustic Analyzer at here.


Press Picture(s) for download here.