NRC rating vary with dB?

[ifsixwasnin9]

ie. As dB increases does NRC rating decrease?

 

[lovinthehd]

What is the NRC rating you're referring to?

 

[j_garcia]

In what context? Your room? I would expect it to remain constant even as SPL increased. This article does not mention what dB it is taken at, in a cursory read.

NRC Rating: Understanding the Noise Reduction Coefficient | ASI

Understanding what an NRC rating is and how it works will help you find the best acoustical product solutions you’ll need. Learn more here!

www.acousticalsurfaces.com

Just noticed that it says that the NRC rating is being phased out.

"The NRC rating is currently being phased out but is still a required calculation so current ASTM C423 tests can be compared to older ones. Its replacement is the Sound Absorption Average (SAA), which takes the average Absorption Coefficient over a greater range of frequencies, and with more frequencies in-between; 200, 250, 315, 400, 500, 630, 800, 1000, 1250, 1600, 2000, and 2500 Hz."

 

[highfigh]

ie. As dB increases does NRC rating decrease?

Specifically, what materials are you considering?

 

[TLS Guy]

ie. As dB increases does NRC rating decrease?

No

 

[highfigh]

No

Depends on the material and its mass and the SPL. If the SPL is hgh enough, it can partially compress some materials and that will reduce the NRC. I don't think the OP is dealing with extremes, but that's the reason I asked about which material they were asking about.

IMO, averaging the NRC is going to cause problems if the frequencies aren't stated separately and specific ranges need to be addressed. I also think materials will be mis-used and wrongly recommended, based on this average and confusion when trying to relate the old & new specs.