Best Free AU Plugins for Logic Pro: Part I

Best Free AU Plugins for Logic Pro: Part I

When it comes to audio, plugins are to present-day production what outboard gear used to be until a few years ago. In many cases, high-end plugins can be almost as expensive as their hardware counterparts, but fortunately there is no lacking of free, and often high quality, alternatives.

Although Logic Pro already comes with its own, high quality and comprehensive set of plugins, suitable for most audio purposes, there are times when the user needs a specific function or simply wants to add new flavors to the audio palette: this is when third-party plugins come handy.
What follows is part one of a two-parts review, entirely dedicated to the best free AU plugins currently available on the market.

Nicola Loverre

Red, Hot and Blue

Red EQ is a three, fixed-bands, equalizer, basically a graphic EQ. It provides 16dB cut or bust on 80 Hz, 1.8 kHz and 8kHz. Certainly not aimed at “surgical“ operation, the Red EQ is suitable for broad band strokes or coloration of the incoming signal. The bands chosen are actually extremely effective, especially on drums or on the mix bus. Input and output gains are independently adjustable, with a useful level meter at the end of the signal chain. The only small drawback, at least in its au incarnation, is the “EQ in“ button, which does not provide a visual feedback when active or inactive.


The installation process is a bit less straight-forward than usual: in order to download and install Red EQ, you first have to add it to your shopping cart from here and then proceed to checkout. A free Acustica Audio account must be created, after which the download link will show up in your browser.

Saturation Knob

Saturation Knob is a freeware Softube product. Basically, it is exactly what the name implies: a one-knob, three-positions switchable saturation plugin. It adds harmonic distortion to the incoming signal, in continuously variable amount; its front panel switch features three positions: Keep High, Neutral and Keep Low; these apply three types of distortion, each one aimed at preserving a specific range of frequencies, and the results range from subtle to dramatic, depending on th amount of distortion the user dials in. Possible uses include, for example, adding more grit to a kick drum, using the Keep Low function, helping it cut through the mix or completely distorting a drum loop. It can be downloaded absolutely free from here.

Saturation Knob free

The installation process includes the use of Softube’s proprietary installer, which then launches a dialogue window, listing all of Softube’s plugins the user wants to activate a license for. In this case, of course, the license is free, but the same procedure must be followed.

Blue Cat’s Freeware Plug-ins

BlueCat audio have made a name for themselves after releasing not just one, but an entire bundle of freeware AU plugins. Their free bundle includes: chorus, flanger, spectrum analyzer, gain utility, phaser and an EQ. We will go deeper into the functionalities of each module of the bundle in our next article, focusing for now on the EQ alone.


Triple EQ is a 3 bands, semi-parametric equalizer, with a very slick and attractive user interface. The Q is not adjustable, therefore not making it fully parametric. It comes in both stereo and dual channel configuration, which can be linked together or left completely independent. Interestingly, all of the products in bundle have in common adjustable transparency for the gui, very useful when you want to keep the plugin’s main window active while keeping an eye on what happens in the background. Personally, I have found myself many times using their EQ as a favorite tool for high-passing tracks, although its use is far from being limited to this task. Installation on AU platforms is pretty straight-forward and consists in just downloading the .dmg file from here, mounting the virtual image and the copying the AU components to your Library/Audio/Plugins/Components folder.

Next set of free plugins takes us to the realm of dynamics.

Rough Rider

Rough Rider free

Rough Rider can go quite extreme with its settings, watch your speakers!

Audio Damage Rough Rider is a bit of an unusual, creative-oriented compressor which comes with a bunch of presets and still remains 100% manually tweakable. Its settings lean a bit towards the extreme, with ratios reaching up to 1000:1 ( ! ) and +30dB of makeup gain. The traditional “ threshold “ knob has been renamed “ sensitivity “ with the higher values corresponding to the lowest threshold settings, in dBs. Its uses can range from the more traditional ones of a compressor to completely squashing and distortion of the incoming signal. Particularly suited for parallel compression. If you are looking for a “ gentle “ compressor, this might not be right choice; if, however, extreme compression is what we are looking for, this is definitely a go-to plugin.
Rough Rider can be downloaded from here.

Kotelnikov by Tokyo Dawn


Kotelnikov is a very comprehensive, mastering-oriented compressor.

On the opposite side of the spectrum we find Kotelnikov by Tokyo Dawn: a dynamics processor with an incredibly vast palette of options. The list of features includes: individual release control for peak and RMS, Delta preview to audition the difference between compressed and uncompressed signal, sidechain highpass filter, and many others. This particular compressor plugin is aimed at precise, transparent dynamics processing: even mastering engineers can benefit from its many options and “ controlled “ sonic behavior. Absolutely a must-have. Here is the download link.

Faraday Limiter

Faraday Limiter is….well, a limiter. In this case though, coders have come up with something totally different from Kotelnikov: their intention was to recreate an analogue-modelled transformer sound. In other words, not a transparent peak limiter, but a colorful one. The result is a pleasant sounding, un-harsh plugin with a distinct tonal character. You can check few examples of its sound below and download the plugin from here (64 bits only).

Goodhertz presents us with a very straight-forward and elegant installer, as shown on the picture below: just drag the AU component to the folder and done, the plugin is ready.


The clear, no-frills installation interface for Faraday.


Flux has come up with an extremely useful processor called Bittersweet, which is essentially a transient designer. Its main control is a big central knob which can be used to continuously dial in values ranging from “ sweet “ to “ bitter “, the former decreasing and the latter increasing the transients’ amplitude.
A “ mode “ control affects the stereo signal: Main affects the entire signal, while choosing the Center position, only the mono, central portion of the signal is processed. If stereo is selected, only the side signal is processed.


Bittersweet can operate both in stereo and M/S mode.

The most obvious use of Bittersweet is of course on drums and especially snares, to help transients cut through or, conversely, to tame them without using a compressor, for example. But its use is not limited to drums, and has proven to be very effective on synth leads or guitars, when capturing more energy from the strumming etc. Flux Bittersweet can be downloaded from here.

Continue to Part II

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