It is useful to find which part of a device is emitting a specific frequency. The part emitting the frequency may not be the original source of the energy but it is part of the transmission path.
The XL2 with Spectral Limits/Noise Curve option allows you to listen to the sound through a 1/1-, 1/3-octave, 1/6-, or 1/12-octave filters. You could but the XL2 mic on a mic boom pole https://www.bhphotovideo.com/c/product/770230-REG/On_Stage_56791_MBP7000_Microphone_Boom_Pole.html to get the mic close to different potential sources.
You could the listen to bandpassed sound through headphones as you move the mic from potential source to potential source.
To use the feature:
Thanks for you question.
Spectral Limits Option is a separate option.
If you are in North or South America you can order it from our web shop https://shop.nti-audio.com/pd-spectral-limits-option-slo.cfm
We then email you the code and you can install.
Outside the Americas, please contact your local NTI office https://www.nti-audio.com/en/contact
Do I purchase the Spectral Limits Option for the XL2 separately or is it included in the standard machine?
Is it software that can be downloaded and installed.
How can I buy it?
The picture got left off the initial post.