A question to plugins, especially EQ

Hello, folks!

I’m still fairly new to mixing and mastering of self recorded music and using plugins with Ardour. So I watch regularly tutorials on YouTube about such stuff, i.e. of Paul Davids, a dutch guitar player. He showed a very interesting feature while using an EQ plugin. In general, I know what an EQ is and how it works, but this was new to me. He demonstrated the use of the lowpass filter and with a keystroke, the plugin switched the output to the filtered out signal to make hearable, what was cut off. I have to confess, that I mostly use CALF plugins so far, because they seem very intuitive to work with, so I don’t know, if there are any other free EQ plugins, usable with Ardour on Linux, that do that in a similar way. If i.e. the CALF EQs should be able to do so, I didn’t find out yet, how to manage that. So please feel free to spread your wisedom.

The general advice you hear in these forums is do not use CALF plugins, they are prone to problems and tend to be of poor quality.
The EQ plugins which come with Ardour are fine to use. Are you using the build of Ardour from this site, or one which was installed with a linux distribution? The build from ardour.org comes with some additional plugins.

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Hey, Chris!

I use Ardour on Manjaro. Have it installed from the repos. Also all plugins I could find. I also followed a YouTube video of Unfa. It’s a big list. Usually I narrow it to Gate, Limiter, Compressor, EQ and reverb and the fluidsynth plugin.
Calf plugins on the other hand I remembered from former attemps of home recording and some mixing. I found them easy to use and self explanatoring. The graphic display helped me a lot to understand what they are doing with the signal.
Maybe it would be helpful for me and other beginners to know, which are this fine additional plugins, that come with Ardour, so I can give them a try?
(Oh, and by the way - I never had any problems with the CALF plugins I used so far.)

Yes. Are the Calf plugins at a standstill development-wise? The known issues brought up by R. G. and others could be easily fixed, no?

With the rise of the gorgeous LSP plugins, I’d say there isn’t much interest in doing that.

I think Robin addressed this somewhat in his recent interview whose link is posted elsewhere in this forum. It seems the needed fixes would change the sound of the plugins, which would affect sessions made with the existing plugins. The Calf maintainers are reluctant or unwilling to accept these types of pull requests, which I think is understandable.

Could someone fork Calf and make a new set of similar plugins that resolves the issues? I believe so, but I wouldn’t imagine that would be easy. I would think it a considerable investment of time to maintain a separate project, and Robin is busy with Ardour. Sadko made the decision to write his own set of plugins rather than forking Calf, and from what I gather, the DSP in his plugins is very good, so for those who are not satisfied with Calf plugins, the LSP plugin project seems to be a very good alternative.

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Agreed, but I need to mention one thing this one time: Although they have long been unmaintained, a lot of people still find them and use them when they start mixing. IMHO this has a lot to do with the GUI which I guess looks inviting, professional and (sorry, Paul) “intuitive” at the same time.
There’s still no match for that in any free-as-speech-and-beer plugin pack.

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Yep. that would apply to all the multiband FX, which introduce phasing artifacts and also do not have a flat freq response. (crossover filter bank don't have a flat frequency response · Issue #217 · calf-studio-gear/calf · GitHub).

As for the calf EQ, as long as it is not automated it is probably fine. Otherwise beware of zipper noise when any control is changed.

Some references:

As with everything in music, if sound good to your ear go with it.

Just be aware that what calf GUIs display is not what you hear (and that includes the calf-analyzer).

Wait does ardour EQ have a hidden band solo feature??

why can’t calf create a new version of their plugins thus not having their plugins change sound for everyone. Doesn’t sound like a good excuse, I like LSP but if calf had better dsp hands down I would use them over LSP.

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You would have to ask the Calf maintainers, but I imagine they don’t have the desire or resources to maintain two versions of the plugins. There hasn’t been a lot of activity on their GitHub page over the last 3 years. If they aren’t doing much work on the main project, it is probably safe to assume there is no appetite on their part to split the project.

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If that’s the case it’s a real bummer, I really do like their work, there plugins just need regular maintenance or at least knocking out some of the major issues stopping them from being a good solid option.

As a career FLOSS developer, with a huge pile of Python libraries for which I’m at least notionally responsible, I can testify that burnout and apathy are a thing for maintainers of long-stable FLOSS software: touching such libraries / apps at all, even to do something as seemingly simple as adding support for a new version of Python, can turn into days or weeks worth of work, often for what seems like minimal improvement or (intangible) reward. I say “intangible” because effectively nobody offers to pay for such “janitorial” cleanups, but the pitchforks and torches come out when a new update breaks their own workflow / usage patterns.

I don’t know the Calf plugin developers, but can easily imagine that risking outrage from their long-time users to fix use-cases which don’t affect (most of) them could be quite unappetizing, even if they haven’t collectively or individually moved on to new projects.

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That’s just the nature of software development - its not confined to FLOSS. In fact as an independent developer in the commercial space there’s possibly greater pressure because you may have a perceived imperative to keep everything working for your customers, while its become the norm that you can’t / don’t charge for updates. So you can burn 90% of the development time and resources just doing work that can’t be charged for, and the best outcome is that at the end everything still works the same as it used to and (ironically) that no-one notices. With plug-ins you’re also dealing with OS updates, new formats, host application updates, SDK updates etc etc.
I’m not sure if its possible to quantify (for those who have never been involved in software development) the sheer vast amount of work that goes into making (and maintaining) some of these things (I’m typing this at midnight on a Sunday…). As an example, in my case a typical plug-in (will re-use some code, but) may have at least 50,000 lines of code in it, and I will have written every single one at some point. That’s my choice, but it takes a special kind of madness to want to get involved at all :slight_smile:


This makes me want to consider an analog desk lol. Atleast it will always be available to use. Software is becoming a nightmare for me. But then again things have to be maintained. Maintenance is key and technology always is changing and progressing. Just wish things were more smooth in regards to just reliability. I can’t rely on any software, only ones that are cared for are the ones that will be available now and In the future

Its kind of the same - you can’t necessarily get spare parts for (especially modern) analogue equipment indefinitely. Perhaps the difference (mainly from a developer point of view) is that its not normal for analogue equipment manufacturers to provide spare parts, service and repair in perpetuity at no cost.

The alternative to that - in the commercial world at least - is a software subscription model, but personally I’ve never wanted to go down that road either as a customer or a developer.
Whether open source or commercial, audio software and plug-ins in particular seem to demand a very specific and diverse mix of skills which significantly reduces the pool of available developers too.

Also for me I wanted something stable long term, not really tons of new features all the time, but sitting plug-ins eventually stop working as new operating systems and versions are released.
This really does also make me want to just create a offline system and just lock in. I need things to work year round. It’s really a lot at times to keep up.

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You can certainly do that, with Linux you can normally control which updates you want to install. AVLinux is a good audio specific distribution in that regard. As I understand it, its philosophy is to give you a stable system which you can lock down and won’t unexpectedly auto-update in the middle of a project and break everything.

It’s funny because I have lots of good paid plugins on my Mac system but I still have a desire to mix on a Linux setup.

Tasks such as video / 3D CAD rendering, etc etc were once traditionally the domain of high-end Unix or (Unix like) workstations, so it’s always kind of made sense to me that Linux would (or should be) the ideal platform for ‘in the box’ audio projects too. (I suppose if you’re using a Mac, then technically you are using a high-performance Unix system under the lid, but for various reasons I’ll choose not to include that :slight_smile: )