HP Filter in Parametric EQ Adobe Audtion 13

[davido62559002]

Wondering why if you apply a High Pass Filter (preset or manual) in the parametric EQ does it raise the volume of the frequencies beyond the frequency that is set for the high pass.

This happens everytime I apply this sort of filter in parametric EQ...but if I apply the same settings in the 30-band EQ...it does not happen.  I do not have any sort of output gain increase set up in the parametric (it is set to the baseline).

Shouldn't the HP filter only lower the volume of the frequency that falls below the setting?  Why is is affecting any frequency above the set HP filter?

Thanx,

David O.

[SteveG_AudioMasters_]

Well it doesn't here. Can you tell us exactly what you are doing?

[davido62559002]

Im only adjusting the HP usually up to 100. You can see everything I've
changed in the attached images.

[SteveG_AudioMasters_]

For some reason I couldn't see those earlier. That's almost certainly the forum's fault... anyway the generic answer to your question really revolves around what happens at the turnover point - especially on steeper slopes. You end up with what's known as passband ripple, which generally has the effect of increasing the level of frequencies near it. The response shown on the effect graph is idealised. This is quite normal - read this SOS question reply. 

[davido62559002]

Thank you very much for the info!

David O.

[paulfigg]

To circumvent the resulting disproportionate energy (and loss of headroom) - try using a Linear Phase EQ - and/or look into Phase Rotation. I wrote this up in 2014: "Asymmetric Wavesforms: Should You Be Concerned?" 

-paul.

@produceNewMedia

[davido62559002]

This is very interesting!  Thank you for the info.

David O.