The THD Meter is documented in the next revision of the ‘Foo manual. It
\nwas originally intended for internal use only, but after many requests
\nit has been added to the release version. This is why the UI is not
\npolished.
\nTo select your input, hold the control key and click on the settings
\nbutton. This will allow you to select your input signal.
\nThe Frequency Locked indicator will come on when the THD Meter senses a
\nsingle frequency signal, and will display the frequency.
\n– The S\/(N+D): display shows the signal to noise plus distortion
\nmeasurement.
\n– The THD+N display shows the total harmonic distortion plus noise
\nmeasurement.<\/p>\n
Both measurements are shown as a percentage, as well as their levels in
\nrelative (dBr) and full scale (dBFS) units.<\/p>\n
The THD Meter also shows the input level referenced to full scale. By
\nclicking the “A-Weight” checkbox, the results may be weighted.<\/p>\n
To properly use the THD meter, you must analyze a single frequency
\nsignal. An easy way to do this is by using SpectraFoo’s Signal
\nGenerator, with synchronization enabled.<\/p>\n","protected":false},"excerpt":{"rendered":"
The THD Meter is documented in the next revision of the ‘Foo manual. It was originally intended for internal use only, but after many requests it has been added to the release version. This is why the UI is not polished. To select your input, hold the control key and click on the settings button….<\/p>\n