AU | VST | AAX - Which plug-in format should I install?

As you have probably noticed, the ERA Bundle installer provides 4 format options for each plug-in. 

1. VST
2. VST3 (Pro plug-ins only)
3. AU 
4. AAX

Of course, installing all the available formats will not affect your system or the performance of it. However, in case you want to install only the necessary components, please read the following guidelines and decide which format to install based on your:

• Operating System
• Host
• Workflow

VST (Virtual Studio Technology) is one of the most popular audio plug-in formats. It stands for Virtual Studio Technology and it was designed by Steinberg in 1996.

As of today VST has evolved into its 3rd version and is commonly referred to as VST3.

On Windows, it is one of the standard plug-in formats, and you can be pretty certain that your DAW or NLE will support it. The VST format is also compatible with macOS.

AU (Audio Unit) is Apple’s equivalent. It has similar functionality to VST, but it’s exclusive to software developed for the Apple platforms.

AU is compatible only with macOS systems.

AAX (Avid Audio eXtension) is a plug-in format developed by Avid, the company behind the popular Pro Tools, audio recording and editing system. It works with Pro Tools and Media Composer and comes in two versions, AAX-Native and AAX-DSP.

AAX DSP — compatible with Pro Tools|HDX only 

AAX Native — compatible with any system running Pro Tools/Pro Tools HD 10 or higher

Below, you can find a compatibility table that sums it all up:

I’m a macOS user! Should I use AU or VST2/VST3 in my host?

AU is a format maintained by Apple and exclusively for macOS. If you intend to share your projects with Windows users then you should use the VST2 or VST3, which is cross-platform. Make sure that your host supports at least one of them. 

I don’t use Pro Tools. Should I install the AAX format?

TL;DR: No! AAX is an exclusive format for Avid products, so you only need it if you use a host provided by Avid, i.e. Pro Tools, Media Composer, etc.