REW EQ Not Matching With Equalizer APO

[lopi]

Hi, I'm trying to make an FIR filter for my headphones, using the "generate measure from filters" fonction.

I'm using my eq parametres from Equalizer APO for that. Only problem is that the filters seem to match up to 1kHz, but then deviate quiet significantly (see pictures below). It's not just graphical bug, I can hear it.
Does anybody have an idea why the filters don't match, and what can I do make them translate ?


(I use Generic EQ, and set none as target type, with no room curve)

 

[John Mulcahy]

The difference is due to the sample rate for which the plots are generated. The generic equaliser, with no measurement loaded, defaults to 96 kHz. The response of a filter set at 96 kHz differs from the response at 48 kHz, due to the warping effect which occurs as the limit of half the sample rate is approached, see the plot below. PK filters will have zero gain at half the sample rate, so the main culprit for the first filter set is the very wide PK filter you have placed at 19.218 kHz. If you want to bring down the high frequencies you shouldn't use a wide PK filter, it would be better to use a high shelf filter instead. For example a HS 6dB filter placed at 10 kHz with a gain of -8 dB would work much better (the 3rd and 4th traces below).

 

[lopi]

Thanks for your reply and advice, I didn't know peak filters behaved that way!
Although as I didn't design this particular eq but rather picked one in the AutoEQ Library, that makes me think this must be a widespread but quiet unknown issue, because none of the eqs in the library either tells the sample at which the eq settings were made, or as you said featured a shelf filter which would solve the problem.