Adapting PEQ profiles

[vco1]

I'm using the PEQ in HifiBerryOS as my main EQ. That one doesn't support all frequencies though. It mostly seems to support multiples of 100Hz, except for the (very) low frequencies.

E.g. a profile may have a peak filter for 1550Hz, while the HifiBerry PEQ supports 1500Hz and 1600Hz only. What would be the best way to adapt the profile? Simply use the next higher or lower frequency? And if so, would higher or lower be preferred? Does that depend on the frequency and/or filter? Or should I also adjust the gain and/or q-factor in that case?

 

[tomtoo]

I'm using the PEQ in HifiBerryOS as my main EQ. That one doesn't support all frequencies though. It mostly seems to support multiples of 100Hz, except for the (very) low frequencies.

E.g. a profile may have a peak filter for 1550Hz, while the HifiBerry PEQ supports 1500Hz and 1600Hz only. What would be the best way to adapt the profile? Simply use the next higher or lower frequency? And if so, would higher or lower be preferred? Does that depend on the frequency and/or filter? Or should I also adjust the gain and/or q-factor in that case?

Its not a PEQ. In a PEQ you can define center frequence and Q free.

If you are at high frequences lets say 2k+ that 100Hz not realy matter much with low Q.

 

[Jimbob54]

That is not a parametric EQ (PEQ) where frequency, shape of slope and amplitude are configurable. That is a Graphic EQ (GEQ). You mightg get away with lower frequencies where wide filters are usually used, but for higher frequencies you might end up making the response worse , not better by boosting/ cutting a frequency near but not at the point you wish to adjust or by applying a filter with too broad an impact.

If you want to use precise PEQ you might want to look at a better EQ solution https://www.audiosciencereview.com/...ows-linux-macos-ios-ipados-and-android.18450/

 

[IAtaman]

Well, if the option to adjust frequency, gain and Q is there but with some limitation on frequency, I suppose one can still call it parametric EQ. Maybe even Selective Spectrum Parametric EQ to make it sound like a feature rather than a limitation?

There are people a lot more knowledgeable on this forum so I hope they can chip in and enlighten us if I am wrong.

To the best of my knowledge, I don't think that would matter a lot if you go 50hz higher or lower at 1500hz. At the lower end, 50hz is big difference, 50hz and 100hz are very different sounds but I'd say 1500hz and 1550hz not that much. I mean 58hz to 103hz is the full octave at the lower end while 1550hz and 1600hz are sharper G and a bit sharper G. Plus the target is smoothed out anyway, and the measurements are for the rig and not for your head and ears. So the whole thing is an approximation at best.

And then there is the masking of frequencies that gets wider as you move up the frequency ladder, which might play a role as well.

If I were you, and I did not have an option to get full parametric EQ, I would pick one approach and go with it, see how that works for me and adjust to taste.

 

[tomtoo]

Well, if the option to adjust frequency, gain and Q is there but with some limitation on frequency, I suppose one can still call it parametric EQ. Maybe even Selective Spectrum Parametric EQ to make it sound like a feature rather than a limitation?

There are people a lot more knowledgeable on this forum so I hope they can chip in and enlighten us if I am wrong. To the best of my knowledge, I don't think the that would matter a lot if you go 50hz higher or lower at 1500hz. At the lower end 50hz is big difference, 50hz and 100hz are very different sounds but I'd say 1500hz and 1550hz not that much. I mean 58hz to 103hz is the full octave at the lower end and while 1550hz and 1600hz are sharper G and a bit sharper G. Plus the target is smoothed out anyway, and the measurements are for the rig and not for your head and ears. So the whole thing is an approximation at best.

If I were you, and I did not have an option to get full parametric EQ, I would pick one approach and go with it, see how that works for me and adjust to taste.

No if a car can jump 20m wide its still not a airplane.

 

[Trouble Maker]

No if a car can jump 20m wide its still not a airplane.

 

[IAtaman]

No if a car can jump 20m wide its still not a airplane.

True.

How about if it could jump 2000km? Or, at what distance do you think the distinction between a car and an airplane would have no difference?

 

[tomtoo]

True.

How about if it could jump 2000km? Or, at what distance do you think the distinction between a car and an airplane would have no difference?

See we can start at the beginning, whats a car and whats a airplane?
One usually drives at a road the other usually flyes. You can mix that up like you want.
The same with a parametric eq, a para lives from changing the center frequence fluently.
While a gr eq has fixed center frequencies.

You can talk about quasi or semi paras what ever you like. BUT a eq with fixed centers is not a para.

 

[vco1]

Thanks all. This was meant as an honest question about using an equalizer (keeping it neutral now). But it turned into an almost religious discussion about the absolute definition of a parametric equalizer.

 

[somebodyelse]

Either something has changed under the skin or this is just a GUI issue - https://github.com/hifiberry/hifiberry-dsp does not have fixed centers. https://www.hifiberry.com/docs/software/implementing-room-acoustics-correction-using-rew/ shows import of parametric filters in REW's format.

 

[Jimbob54]

Thanks all. This was meant as an honest question about using an equalizer (keeping it neutral now). But it turned into an almost religious discussion about the absolute definition of a parametric equalizer.

This is the way of ASR.