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Topic: Dynamic Loudness Control (Read 2977 times) previous topic - next topic
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Re: Dynamic Loudness Control

Reply #50
I ddn't mean that red (iir PEQ from foo_dsp_effect) is ideal. It cannot be ideal, because granularity is settings is limited to whole dB, not fractions of dB. Also i didn't mean QRange is bad. I just meant that pre-made impulses from https://github.com/jaakkopasanen/AutoEq/tree/master/results are definitely off-pair with results from parametric EQs.
To me it seems visually that curve from ffmpeg is closest to reference curve that can bee seen in pdf from Oratory, so i would use ffmpeg. Also, there is PEQ in SoX, but i didn't try it yet.
Would you like me to generate an impulse response with IIEQPro and send it to you, so you could check it against the "theoretic ideal" ?
If you will do this for m50(x).

Re: Dynamic Loudness Control

Reply #51
I misread your post !  :o

You wrote this :
Curve from Oratory.
Red - iir filter from foo_dsp_effect,
orange - ffmpeg parametric eq,
yellow - QRange,
green - impulse from https://github.com/jaakkopasanen/AutoEq/tree/master/results

But I understood this :
Curve from Oratory. Red
- iir filter from foo_dsp_effect, orange
- ffmpeg parametric eq, yellow
- QRange, green
- impulse from https://github.com/jaakkopasanen/AutoEq/tree/master/results

I know, it makes no sense, but that's what I understood. In my country, dashes are separators.  :D Now I see what you mean !
So ffmpeg and QRange are quite close and probably hard do distinguish by ear.

Here are 3 impulse responses for you. They are from Oratory's M50x preset (this one : https://www.dropbox.com/s/r7wa83eb53da6fh/Audio%20Technica%20ATH-M50x.pdf?dl=0 ).
All were made with a 4096 samples basic pulse @ sample #2048.
  • First one : QRange with these settings : "Low Distorsion" and "Minimum Phase".
    I have been told in another forum by a QRange user that "Low Distorsion" and "Minimum Phase" should be better for Hi-Fi. Now we can see if that's true.
  • Second one : QRange with very different settings : "Good Frequency Response" and "Insane (Linear Phase)".
  • Third one : IIEQ Pro (no settings available)
    IIEQ Pro offers Low Shelf, High Shelf, plus 17 other filters (see here : https://fr.scribd.com/document/355586010/IIEQ-Pro-Manual ). I chose Ana Peak for all the Peak filters (bands 2 to 9) as it really seems to be the one to choose.

Let's see what your graph says !  ;)

Re: Dynamic Loudness Control

Reply #52
Red - ffmpeg, orange - IIEQ Pro Ana Peaks, yellow -  QRange Good FR Insane (Linear Phase), green - QRange Low Distorsion Minimum Phase. As you can see there are no differences between yellow and green. But actually minimum phase is preferred, because with minimum phase there is no pre-echo and human hearing is more sensitive to pre-echo than post-echo.

Re: Dynamic Loudness Control

Reply #53
Thanks ! It's good to see that everything is really close until 7 KHz. Even beyond, they all stay within 1dB of each other. So differences will probably be hard to hear, unless there are phase shifts and other weird stuff.
In that context, I would hesitate between IIEQ Pro (orange) and QRange Minimum Phase (green). Here are the pro/cons :

IIEQ Pro :
  • Pro : like the manual says, Ana Peaks are adjusted to prevent treble warping, the peaking curve remains symmetrical up to the Nyquist frequency (which is analogue behaviour, hence their name)
    Nyquist frequency is half the sampling frequency, so 22.05 KHz for 44.1 KHz, so if IIEQ Pro prevents treble warping until that frequency, I guess it's a really good thing.
  • Pro : seems closer to ffmpeg, which as you said is closer to the "ideal EQ".
  • Con : there is no phase setting, so how could I know what happens with the phase ?

QRange :
  • Pro : I can set phase to minimum
  • Con : if their peak filters are classic digital ones, there is a risk of treble warping indeed.
  • Con : not as close to ffmpeg as IIEQ Pro

Maybe QRange (green) is the best choice since at least I can set phase to minimum (I'm just unsure about this setting : "Low Distortion", "Medium Distortion and OK Frequency Response" or "Good Frequency Response").
And maybe IIEQ Pro (orange) is the best choice, since it seems closer to ffmpeg and it prevents treble warping.

PS : in case it matters, both QRange and IIEQ Pro are IIR-based, not FIR.


Re: Dynamic Loudness Control

Reply #55
Interesting, thank you :) Then IIEQ Pro is indeed the best choice : minimum phase + closest to ffmpeg over 7 KHz. I hope I'm not missing anything.

 
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