Questions & Answers


Installation & Compatibility

x42-meters, x42-eq, and x42-whirl are included with the Harrison Mixbus™ DAW.
If you have Mixbus or Mixbus32C, you do not need to install these separately.

The software comes in two formats: a standalone application and a plugin.

The installer puts everything in the right place. No manual intervention is needed.
Compatible with Windows XP and later.

The package installer deploys the plugin automatically. It offers a choice between system-wide installation (requires admin privileges), and per-user installation.
Compatible with OS X 10.6 and later macOS (Intel 64bit, Intel 32bit), as well as and OS X 10.5 (PPC). A separate download is avilable for Apple M1 (ARM CPU) systems.

Note: The application is not digitally signed. On Yosemite (10.10) or later, right-click (or control + click) and select Open from the context-menu to launch it. Since Big Sur (macOS 11), you may have to Disable the Gatekeeper, when you install the plugins in a way other than using the .pkg.

(As alternative an .dmg download is provided for power-users wishing to deploy plugins themselves. This disk-image also includes a standalone JACK app that can be drag/dropped to /Applications).

GNU/Linux (Intel):
Unzip the .tar file, move the lv2 plugin to $HOME/.lv2/ and the application to $HOME/bin. A Linux installer is in the making. Please stay tuned.
Compatible with all GNU/Linux distributions since circa 2009 (glibc ≥ 2.2.5), Intel x86 compatible systems (SSE2 or better), requires X11 and openGL ≥ 2.1.

GNU/Linux ARM:
These builds are intended for Linux running on ARM CPUs (e.g. Raspberry Pi). The same install instructions as for GNU/Linux x86 builds apply.
Compatible with all GNU/Linux distributions since circa 2014 (glibc ≥ 2.17), ARM 32bit (hard-float, NEON) or AARCH64, requires X11 and openGL ≥ 2.1.

Prerequisites / Hosts

The LV2-Plugins need a LV2 capable plugin-host, see below.

The standalone application requires JACK. Please see Downloading JACK.


License File installation

Please see License File Installation page which includes a concise description and a video.

Purchasing a License

The x42-plugins are available as partner product from the Mixbus Store.

Manual License File installation on Linux and OSX

On GNU/Linux and OSX, copy the license file into your home directory as $HOME/.x42_license.txt.

Manual License File for Windows

The file needs to be saved as as %localappdata%\x42_license.txt.

This is usually expands to C:\Users\YOUR-USER-NAME\AppData\Local\x42_license.txt, to navigate to that folder, open the windows explorer and simply type %localappdata% then press enter.
(Future personalized license files will come with an installer to automate that.)

Licensing Conditions

x42 plugins are licensed in terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

Some binaries are provided as demo. A license/signature file is required to remove the evaluation restrictions: Without a valid signature, the plugins function normally, except the GUI does not respond to any mouse interaction and eventually fades to black. Audio processing is not affected.

The purchased license is strictly personal. You may not share it with other individuals, but it is valid on for all operating systems and can be used on different machines of the owner.

We make every effort to test the software, within the limits of our resources, to ensure compatibility with a wide range of commonly used host systems. Yet, you are strongly advised to test compatibility with your operating system and host applications before purchasing an activation code.

We cannot guarantee to replace lost license-file or software downloads. You are advised to treat purchased software with the same care as physical hardware. License-file download links are time and usage limited as a necessary security measure and should not be regarded as an online backup.

We will offer a full refund if purchased software are deemed not fit for purpose, particularly in a manner which could not have been foreseen by, or was not evident during, evaluation of the free demo copy of the software and where all reasonable steps to remedy the situation, such as software updates or replacement have proved unsuccessful. We reserve the right to ask for proof of purchase if required.

License purchased in error may not be refundable except where it can be shown that they or the products they refer to were inappropriately described or labelled in a manner likely to cause ambiguity or confusion.

If you experience problems downloading or installing purchased license files, Contact Us and we will assist in resolving the problem.

License? I thought they were free-software?

x42-plugins is free in the sense that you are free to do anything with it that you want (including use it on as many machines as you wish, make copies of it for friends and so forth).

«Free software» means software that respects user's freedom. Roughly, it means that the users have the freedom to run, copy, distribute, study, change and improve the software. Thus, «free software» is a matter of liberty, not price.

Some people like to explain this with the phrase "free as in free speech, not free as in free beer".

It is also free in the sense that you can get the source code at any time and build it yourself. This can be a complicated and difficult task.

These plugin suites are complex software projects which requires expertise to maintain and time for quality assurance. The license serves as a signature-certificate. The binary releases are tested rigorously to conform to standards and work correctly - in particular the measurement applications.

This is a time consuming project and without revenue to support its development, it will almost certainly grind to a halt. The licensing system is one way that we try to raise revenue. Please consider being a part of the wonderful group of people who help to make continued development possible.

Donations? Aren't you selling licenses

The donation system is entirely separate and exists for a couple of reasons:

Either way, it allows people to make a simple one-time payment. It is not part of the licensing system, and any payment you make via the donation system does not apply for a license.

Plugin Specs

LV2 ?

LV2 is an open standard for audio plugins, used by hundreds of plugins and other projects.

The most famous DAWs supporting LV2 on all major platforms are Ardour and Harrison Mixbus. A standalone plugin host Carla is also available cross-platform. For a complete list of host please see the LV2 Plugin website.

Why no VST/AU ?

Various reasons, VST is a standard from the 90's and while it is still in widespread use and has mutated a couple of times to reach VST3, it is akin to using Windows'95 in 2015.

Another important aspect is that VST and AU are proprietary standards. While this makes little difference to musicians, x42 strongly believes in software-freedom and open standards.

After all it's the user's rights that are protected: Many audio-engineers often refer to the plugins they use as "my plugins", although when reading the small print, they are not allowed to own them in the first place and merely have a license to use for as long as they follow the terms-of-use.

Plugins only working on proprietary platforms, with proprietary specifications, keep people locked in.


This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

The Windows, Apple and Linux names and logos visible on this site are trademarks or registered trademarks in the USA and other countries, respectively of Microsoft Inc., Apple Inc., and Linus Torvalds.