Measuring SPL by octave band to calculate NC or NR level

[Chris_Adair]

Hi Everyone, I want to measure the noise floor of my cinema, and people ask me what the level is in NR or NC as a single figure ? This requires knowing the SPL at each octave , it seems REW can display a full curve but I can't see how to get octave band SPL ?
Actually I'd be using Leq , but need it perOctave not just a total A/C/Z. Chris

 

[John Mulcahy]

On the RTA set the Mode to RTA 1/1 octave. You can also have REW show the noise curves on the plot by selecting that option in the Appearance settings, the Y axis should be set to SPL.

Edit: more info in the help, the noise criteria figures are shown at the bottom of the Levels panel when the RTA is in 1/1 octave mode.

 

[TSnape]

Hi John, where I have the show noise curves tickbox there's a window that looks like a drop down. Is it meant to show different curves, such as the NR in Europe? I tried clicking on it, both on windows and mac, but it instead actions the tickbox and not the dropdown. Also tried v5.20.1 with the same results.

 

[John Mulcahy]

Yes, it's broken when using the mouse but fixed in the next build. In the meantime click on the checkbox and select to show the curves, then use tab to move to the drop down (and use the up and down arrow buttons to select).