The ability to compare two frequency spectra is often required when setting up PA systems. For example, when adjusting the response of the left/right side of the main speakers or for trimming a series of monitor speakers to have a similar frequency response. Starting with firmware version 2.20, the XL2 supports this task by offering a capture memory in the Sound Level Meter.
A measured spectrum can be stored to the capture memory. The capture memory may then be displayed on the screen together with an ongoing measurement.
In the screenshot, the dashes are showing the capture memory representing the frequency response of the left speaker of a stereo speaker set. The bars are visualizing the spectrum of the live signal; in this example the spectrum of the right speaker.
Using an equalizer, the frequency response of the right speaker may then be adjusted to fit to the left speaker.
Need more such functionality?
Advanced techniques like multiple capture memories, averaging multiple spectra, displaying the difference of two spectra, increasing the resolution up to 1/12 octave are available with the "Spectral Limits Option."