In the jungle of third party Audio Unit plugins, ‘free’ , as in zero cost, doesn’t necessarily mean low quality. Nor does a less funky GUI. Here’s a list of free Audio Unit plugins worth taking for a spin in Logic Pro, or any DAW that supports Audio Units. There’s lots to choose from, happy tweaking!

Flux

Flux offers two free plugins (submitting your email address required):

• Bittersweet II – a transient designer, offering separate shaping of the Mid and Side signal.
• Stereotool – features control of input gain and individual pan for left and right channels. A phase inverter, global stereo pan and stereo width settings, vector scope display, PPM meters for both inputs and outputs, and a phase correlation meter are included.

Blue Cat Audio

Blue Cat Audio, famous for their plugins that have controller output offers a free plugin bundle, available here. The bundle, updated to version II on March 28th 2012, includes:

• Chorus
• Flanger
• FreqAnalyst (Analyzer)
• Gain Suite
• Phaser
• Triple EQ

Most effects are available in Logic Pro , but for a different color, be sure to check out these out.

Brainworx

Brainworx offers two very useful plugins:

• bx_solo – discussed in the ‘Solo The Sides’ series part one, two and three. Requires submitting your email address.
• bx_cleansweep – Lowpass and Highpass filtering with ‘Anti Crush Technology’. Requires submitting your email address.

Voxengo

Voxengo offers a series of free plugins:

• OldSkoolVerb – released early March 2012. This plug-in implements a “classic” stereo reverb algorithm and produces a very “clear spatial image that blends well with the mix”.
• Tube Amp – applies asymmetric tube triode overdrive.
• SPAN – a real-time “fast Fourier transform” audio spectrum analyzer plug-in.
• Overtone GEQ – a 7-band harmonic (overtone) graphic equalizer that supports mid/side channel processing. Overtone GEQ applies harmonic enhancement processing.
• Sound Delay – Sound Delay features internal mid/side encoding and decoding, and allows you to delay mid and side channels independently.
• Stereo Touch – this plug-in takes a mono input signal and generates a stereo output signal.
• Marvel GEQ – Marvel GEQ is a linear-phase 16-band graphic equalizer. It supports mid/side channel processing.
• MSED – use this to extract mid-side channels, swap stereo channels, or switch polarity of a signal.

Camel Audio

Camel Audio has two free plugins:

• Alchemy Player, including 200 presets and 1GB of samples. Requires registration.
• Camel Crusher, a distortion plugin. Requires registration.

Izotope

Izotope offers one free plugin: Vinyl. It will make audio sound as if it was a record being played on a record player. That may sound lame in 2011, but the bursts of noise it creates are random (put it on an empty audio region just to get the effect). Use it as a source for sidechaining for a creative effect, or combine it with Bluecat’s plugins that offer controller output. Requires registering with Izotope.