I have a two-way loudspeaker system in which I do not understand the THD
measurements I obtain with REW. The woofer THD measures like this (first jpg)
before the crossover filtering (low pass LR2, miniDSP):
Then after the low pass LR2 filter it looks like this (2nd jpg), with lots of
distortion above 1.5kHz.
The THD of the two units combined (3rd jpg; LP and HP LR2 with miniDSP) looks like
this, but all that distortion above 1.5kHz is gone.
How can it be that the "distortion" above 1.5kHz which was so obvious in the
woofer trace disappears in the combined unit? I think there must be something
basic about FFT which I do not understand. I couldn't find the answer in the REW
Help PDF.
measurements I obtain with REW. The woofer THD measures like this (first jpg)
before the crossover filtering (low pass LR2, miniDSP):
Then after the low pass LR2 filter it looks like this (2nd jpg), with lots of
distortion above 1.5kHz.
The THD of the two units combined (3rd jpg; LP and HP LR2 with miniDSP) looks like
this, but all that distortion above 1.5kHz is gone.
How can it be that the "distortion" above 1.5kHz which was so obvious in the
woofer trace disappears in the combined unit? I think there must be something
basic about FFT which I do not understand. I couldn't find the answer in the REW
Help PDF.