Verify
When a filter is both in PassiveFilter and in real life, the results can be compared in 'compare'
First import a measurement file with filter. Then chose SPL or Imp and hit 'compare'.
Often you need to measure with and without filter in excact the same position to have a valid comparition.
Then the files in import is changed with the new measurements without filter and compare is done again.
Excpect a difference of half a dB because of Component tolerances, loss and unlinearity.