lkjb QRange

[heavymetalmixer]

Btw, now that you mention it, what implications has the plugin being IIR-based? What differences are in plugin delay, phase and ringing, etc?

I started to write something more in detail but this not easy to get into a concise post. I'll postpone this for an explanation on the wordpress page.

In short an FIR based LP EQ can create any frequency response. An IIR based one on the ther hand uses an IIR filter to process audio forwards and that output again backwards (that is inversely in time). The filter is thus applied twice with a resulting linear phase response. Due to this only "normal" filters (peak, shelf, multiple of 6 dB/oct cuts) can be used resulting in not so different peak and shelf filters but cuts are now multiples of 12 dB/oct.

Ringing is inherent to LP filters and should only depend on the resulting frequency response. The phase might be not so linear for IIR based LP EQs but still sufficientlty linear for not being noticed at all in parallel processing. The delay depends on the used maximum impulse response length and processing implementation and not so much on an IIR/FIR base.

According to this, would it be correct to say that Fabfilter and Izotope LP EQs and IIR-based?

[thecontrolcentre]

Thanks for this. I'll try it out later ...

[lkjb]

According to this, would it be correct to say that Fabfilter and Izotope LP EQs and IIR-based?

I can't say. I'd assume that most LP EQs are FIR-based. The only IIR-based EQs I know of don't call it IIR-based but speak of working in the time domain (which would also be possible for an FIR-based LP EQ but very CPU-consuming).

[Obsolete236871]

There was quite an interesting discussion a while ago on Gearslutz, after the developer of a very highly priced Linear Phase eq claimed that his implementation of Linear Phase had absolutely none of the typical artifacts of LP processors like pre-ringing, which to my understanding are inevitable if the EQ is pushed beyond certain limits. Other users and developers quickly chimed in and discussed the merits and downsides of Linear Phase:

https://www.gearslutz.com/board/masteri ... nging.html

There is also a short article by another commercial developer, that lists everything one needs to know when using a Linear Phase eq:
https://cravedsp.com/blog/linear-phase-eq-explained

From what Ikjb said and the info in the article, I assume that one should rather avoid applying EQ to the lower frequency range and also rather cut, than boost frequencies (preferably in the higher frequency range). I wonder: does applying a highpass / lowcut filter also exaggerate the transient smearing / ripple artifact the way using a peak eq in that lower frequency range does?

[SoundPorn]

Yes this is def the first IIR Linear Phase EQ I ever heard of in fact I even read before from another developer that it was impossible. I don't know what is and what's not possible but I do know this is an extremely helpful tool.

[hannesmenzel]

Thanks for this plugin. Would you tell which framework you used? I saw that you changed from Juce to Iplug lately.

The first two things that came to my mind was trying to use different drawing libs to make the curve drawing a little less pixelated. What's a little confusing for me is that the shelf handle is on half of the gain value, but actually not a big deal.

I'm not so advanced in dsp so could you tell how you do a linear phase eq with IIR filters?

Best wishes, Hannes

Edit: Sorry, didn't realize that the IIR discussion is already ongoing.

[Obsolete236871]

So, here is some background to the Ikjb QRange that I only came to fully realize after doing some research: Last year a big controversy was prompted by a company which claimed that they had invented a Linear Phase EQ that was completely free of pre-ringing artifacts, something that is technically not possible to my understanding.

That EQ was essentially an updated version of the Algorithmix Orange EQ and the company offered it for a price of 950 €. Some guys on Gearslutz became curious of the claims and eventually some DSP guys from other renown companies chimed in. They came to the conclusion that the claims of the EQ having no preringing was absurd and total hogwash. Also, the asking price of 950 € got ridiculed quite a lot, especially when highly praised EQs like the DMG one or the Fabfilter cost only a fraction of that.

https://www.gearslutz.com/board/masteri ... nging.html

Then the man behind the company that offers the 950 € Linear Phase EQ (that additionally requires a rare 50 € dongle, that almost no other audio software uses) participated in a German language live stream, to share his perspective. The guy actually seems like quite a nice person, it's the same guy who brought us the popular "dynamic range meter" some years ago.

During the discussion, he had to admit though that the claim of their 950 € Linear Phase EQ having no preringing artifacts could not be fulfilled. His fellows in the live stream even tried to help him, suggesting that the asked price for the EQ might be too high and not competitive in today's audio software market place. Still, he maintained that their EQ was somehow better sounding, based on subjective and personal notions, that could not be objectively verified. Confronted with some technical details, the guy admitted that he didn't really know the intricacies of Linear Phase processing, since he works with experienced coders who take care of all this.

https://www.youtube.com/watch?v=UiZke6BA3jo

So, Ikjb QRange, has a similar name and layout to that controversial 950 € Linear Phase EQ and I guess can be seen as a reference and response to that controversially discussed EQ. And it's free (vs. 950 €)!

[onerob]

Great, I'll take the free one!

[enroe]

So, here is some background to the Ikjb QRange
...
So, Ikjb QRange, has a similar name and layout to that controversial 950 € Linear Phase EQ and I guess can be seen as a reference and response to that controversially discussed EQ. And it's free (vs. 950 €)!

What a fantastic story!

It is fully in the sense of the free cultural movement . The free-culture
movement has an ethos of free exchange of ideas comprising the free
and open-source-software concept.

Also - there are still many musicicans here who believe that
freeware is inferior to payware.

[Omkar]

2nd round:
"... questions I would have is in how far the max latency does have an impact on rendering
and how the upper regions are performing ..."

refers to 1st round:
viewtopic.php?f=6&t=529574

Premise:
On my mind I placed EQ`s like this to the mastering section I will never touch,
a free one catched my interest to learn something new.

Rendering at max latency had no particular impact on Samp, S1 and Reaper (demo).
Not sure if it represents behavior of all daws on all platforms
and I keep this option open for individual tests.

Upper freq section, broad and narrowed Q don`t bite as I hear it in many other EQ`s,
so called analog ones included.
I dare to say I prefer the EQ results over many others I would usually place on groups or master bus.
Something precise and pleasing there.

When solo functions implemented, an EQ I am very fine with as is
and I stick to impressions of 1st round, precise and fast workflow.
I also feel grateful for the free opportunity at this quality.

Out of pure curiosity, does dev have specifics / improvements on mind?

[lkjb]

Thanks for this plugin. Would you tell which framework you used? I saw that you changed from Juce to Iplug lately.

I used Youlean's IPlug for QRange. I'm still using JUCE for the open source plugins.

The first two things that came to my mind was trying to use different drawing libs to make the curve drawing a little less pixelated. What's a little confusing for me is that the shelf handle is on half of the gain value, but actually not a big deal.

JUCE certainly has nicer looking curves (using thickness) but I must also admit that I didn't investigate much. The alternative to having the shelf handle at half the gain value would be to have it hovering beside the curve which lead to my decision as it is now.

I'm not so advanced in dsp so could you tell how you do a linear phase eq with IIR filters?

I wrote something more detailed about how IIR linear phase works as well as some QRange specific details here.

One other thing: QRange currently doesn't have presets. I thought about adding that but as I wasn't sure whether this is something an EQ needs (for my workflow it doesn't ) and I also wanted to release the plugin it's not implemented yet. Any other opinions?

[hannesmenzel]

Thanks for this plugin. Would you tell which framework you used? I saw that you changed from Juce to Iplug lately.

I used Youlean's IPlug for QRange. I'm still using JUCE for the open source plugins.

The first two things that came to my mind was trying to use different drawing libs to make the curve drawing a little less pixelated. What's a little confusing for me is that the shelf handle is on half of the gain value, but actually not a big deal.

JUCE certainly has nicer looking curves (using thickness) but I must also admit that I didn't investigate much. The alternative to having the shelf handle at half the gain value would be to have it hovering beside the curve which lead to my decision as it is now.

I'm not so advanced in dsp so could you tell how you do a linear phase eq with IIR filters?

I wrote something more detailed about how IIR linear phase works as well as some QRange specific details here.

One other thing: QRange currently doesn't have presets. I thought about adding that but as I wasn't sure whether this is something an EQ needs (for my workflow it doesn't :)) and I also wanted to release the plugin it's not implemented yet. Any other opinions?

Interesting. I thought, IPlug Youlean draws with Cairo. I use IPlug2 by Oli Larkin (though on very beginners level) and it implemented some different libs to choose from, NanoVG, Cairo, AGG and some others. And they share some code as far as I know. I thought Cairo was a little smoother for drawing vector graphics.

[Distorted Horizon]

Just tested on my bassline. AWESOME!! Thanks for the freebie, it's going to be used a lot

[lkjb]

Out of pure curiosity, does dev have specifics / improvements on mind?

At the moment I'm collecting suggestions. There's nothing from my side at the moment.

Interesting. I thought, IPlug Youlean draws with Cairo.

To be honest, I used IPlug Youlean mainly for the resizeing feature. I noticed that it has Cairo support but I didn't check any further since the graphics worked.

[Omkar]

Out of pure curiosity, does dev have specifics / improvements on mind?

At the moment I'm collecting suggestions. There's nothing from my side at the moment.

Perfect, ditto.