Mixbus : Ardour + Harrison DSP for OS X

Harrison, the manufacturer of world-class analog and digital consoles, along with Paul Davis, lead developer of Ardour are proud to announce Mixbus®, a customized version of Ardour for OS X.

Mixbus enhances Ardour by providing critical mixing functions in a knob-per-function interface called "True Analog Mixing"(tm). True Analog Mixing is based on Harrison's renowned 32-Series and MR-Series console designs, combined with Harrison's proprietary digital mixing technology. Mixbus enables the user to record, edit, and mix a musical performance "in the box" while achieving a sound that harkens back to the golden age of album recordings.

Features include:

  • Straightforward “knob per function” mixer layout based on Harrison's renowned 32-series and MR-series music consoles.
  • Precision DSP algorithms for EQ, Filter, Compression, Analog Tape Saturation, and Summing based on Harrison's world-renowned large format analog and digital mixing consoles.
  • Unlimited stereo or mono input channels (based on available CPU power) featuring High-pass Filter, EQ, Compression, and 4 Mix Bus sends on every channel.
  • 4 Stereo Mix Buses (can be used for groups or auxes) featuring Tone controls, Compression, Sidechaining, and Analog Tape Saturation.
  • Stereo Master Bus that features Tone controls, Analog Tape Saturation, K-meter, and Limiting to help you make polished mixes.
  • Plugin delay compensation to support effects such as parallel compression.
  • Comprehensive "at-a-glance" metering with peak, peak hold, and compressor gain reduction visible on every track and bus.
  • Extensive DAW features via the Ardour Digital Audio Workstation.
  • Supports AudioUnit plugins and any CoreAudio interface.

According to Harrison product director Ben Loftis, "Harrison didn't want to launch a "me too" workstation in an already crowded market. Instead, we used the Ardour open-source workstation as the Mixbus recording/editing/playback engine. Because Ardour has been around for nearly 10 years, and has thousands of users, it is a stable platform that doesn't further add to the fragmentation of the workstation market." Harrison has had an ongoing collaboration with Paul Davis since 2004, when they used Ardour as the basis for the Xdubber product

The original idea behind Mixbus was a simple Harrison "channel strip" plugin. But after some experimentation, it became obvious that simple plugins don't interact correctly to recreate console functionality, and freeform DAW summing architecture does not lend itself to analog production styles. So during an extensive testing and experimentation phase, the design morphed into a combination of Ardour and Harrison features in the channel strip.

For those who are familiar with Ardour's existing design, Mixbus was implemented using a single closed source LADSPA plugin to provide Harrison's channel strip DSP, along with a set of extensive but non-intrusive changes to Ardour's core. The source code for everything except the plugin is available as usual via the svn repository at ardour.org. Harrison has been a long-time supporter of Ardour, and they will continue development of the Ardour open-source platform. Some of the proceeds from Mixbus are being directed towards Ardour developers and increased development efforts.

Special thanks to Thomas Vecchione (Seablade) and Malte Rogake for design reviews and testing during the development of Mixbus.

For more details or to purchase Mixbus, go to http://mixbus.harrisonconsoles.com

Any chance that the Mixbus

Any chance that the Mixbus plugin will be released (as binary) for Linux as well, or would this be a problem because of incompatibilities between distributions?

@the CLA: that is precisely

@the CLA: that is precisely the problem. I want to fix this problem for "regular" Ardour too, and when we do, there will be a Linux Mixbus release as well.

Linux! Linux! Linux! Will buy

Linux! Linux! Linux! Will buy it! Will buy it! Will buy it!

What prevents us from using

What prevents us from using the interface (which is built on ardour) together with ladspa effects to have the same level of ITB functionality for standard ardour?

I would also buy it if available for Linux... amd64 please.

Would it continue in 3.0?

Awesome! Will buy if there's

Awesome! Will buy if there's a Linux version!

Hi Paul and the Ardour

Hi Paul and the Ardour team.

Have Mixbus running on my PPC Mac.
Wow ! What a sound from my speakers. Amazing filters and dynamics, and the option for parallel compression is superb
for mastering.


qharley: theoretically,

qharley: theoretically, nothing. in practice, the DSP in Mixbus represents 30 years of development at Harrison. These weren't newly written "plugins", the DSP is the same code used in Harrison's own consoles. The GUI part may inspire some kind of conceptually similar integration of plugins into the GUI in 3.X (something that has been planned in a very simplistic way for a while), but part of the reason this works so well is that there is one plugin and one GUI controlling it for each strip, not one for the EQ, one for the compression, etc. etc.

In terms of a Mixbus based on 3.0 ... thats totally hypothetical at this point, and will depend a great deal on how the release based on 2.X is received by the world.

30 years of development...

30 years of development... That could be good.
There are already some kind of interest from some of my buddies on The Womb. ;-)

There are quite a few linux ardour users that would love this setup. The way I see it, is that the GUI could essentially stay the same, and that the user can choose to use an ardour defined cluster of ladspa plugs, or the Harrison module for linux (which you could buy from Harrison)

It is not that we don't have good quality plugins for ardour, the problem is mostly that they are a bit tricky to control, and it takes time to mix. I currently use the DSP's on my digital mixing console to do all the things Mixbus would do, because doing it in ardour just takes too long comparatively.

Another thing to chew on, is that there are quite a few capable DSP programmers out there that could write similar plugins for Linux, if the interface were known. There could, for instance, be a LinuxDSP module for linux that does the same as the Harrison one, just with different code (and different core sound of course) - and it could generate an income for that DSP programmer should he decide to sell it.

Just spit balling here, but I truly believe that this will drastically change the way ardour is perceived as a user friendly DAW interface.

Pricing looks quite

Pricing looks quite reasonable at the moment. Unless the non introductory pricing is significantly higher you can pencil me in for a linux version should it be released

hey guys, Some time ago, I

hey guys,

Some time ago, I had (during a dream) installed OSX86 on my old (dreamlike) intel based Dell laptop and could run Ardour OSX-X11 on it (still during the dream).

So (the theoretical question) is the MIxbus plugin compatible with IntelMac platforms or is it PPC only ?

(before I awakened from this dream) I scraped my osx86 partition since I couldn't use it for anything (yeah, it's a dream, remember) but I can retry (to dream the same dream) if you Paul tell me that it is also supported on intel platforms.

This is of course for educational purposes and remains a "theoretical" idea or wishful thinking. Do not install OSX86 on non certified platforms :)

So (the theoretical

So (the theoretical question) is the MIxbus plugin compatible with IntelMac platforms or is it PPC only ?

IntelMac is what I tested it on for the past several months. That being said in your dream world I can't comment on it on a OSx86 machine obviously;)


Ciao Seablade, if I (dream

Ciao Seablade, if I (dream that I) install OSX86 on my (dreamlike) PC, should I (dream that I) buy a copy of Mixbus or can it be tested for free ?

At the moment there is no

At the moment there is no demo I know of, sorry.

This looks very exciting. I

This looks very exciting. I have not been mixing much stuff recently, but will keep an eye out for a version OS X 10.6 compatible as I am about to upgrade my os. I hope this continues to run parallel to Ardour development as these DSP options mixed with the features which Ardour3.0 is going to have under the hood would make a pretty rocking combination.

Thanks for the work.

Are there significant changes

Are there significant changes to the rest of the interface or would one feel at home switching between Ardour and Mixbus? Or do one really not gave to swicth between them to reach each versions advantages as they are and are working the same (except for the mixer)?

Are the onboard eq controls, bass and treble sweepable shelving filters plus a semiparametric mid?

Roger: The Editor page is


The Editor page is identical in both products. You won't have any trouble going back and forth (except that the Mixbus elements are missing in Ardour, of course)

The track EQ's are Lo Shelf, Mid Peaking, and High Shelf, all with sweepable frequencies. The buses are similar but with fixed frequencies.

The official promotional

The official promotional video is a hell of a great demonstration of Ardour!


looks cool. I would like to

looks cool. I would like to hear how it sounds though. Not on youtube obviously :)

Will Mixbuss be on AES next

Will Mixbuss be on AES next weekend?

I WILL buy. But only if the

I WILL buy. But only if the linux version comes out. Differences between distros? True, but with just a .deb and a .rpm you cover 99% of linux users.. Is it such a big issue?

@vervelover- Yes sadly. It

Yes sadly. It isn't quite as simple as that unless we do something that most distros don't like;)

You shouldn't have much problem at all switching between Ardour and Mixbus. There are some differences, but the majority of it is pretty similar.


can mixbus import ardour

can mixbus import ardour projects and vice-versa?

can mixbus import ardour

can mixbus import ardour projects and vice-versa?

Yes and No. Ardour importing

Yes and No. Ardour importing Mixbus you would lose all the processing and settings that were done in Mixbus. But the session itself should open fine, and the mixbus busses are replaced with standard busses named IIRC mixbus-1 through mixbus-4. Obviously no processing on them though.

Mixbus importing Ardour should be possible (In fact it was one of the things I tested when I was testing mixbus), though there seem to be a couple of hiccups for some people right now IIRC. They are being worked on I think.


This looks pretty cool, but I

This looks pretty cool, but I would have to see a Linux version before spending money on it since I transfer sessions between my desktop (ubuntu) and laptop (OSX) quite often. On the other hand though, looking at the screenshots has given me the idea of creating a session template/track template with the same setup of effects (free ladspa versions of course). I'll post when I'm done.

partially proprietary? that's

partially proprietary? that's very off-putting...
is the rest of it GPL'd ?

Will there be a version of

Will there be a version of mixbus based on ardour 3 with midi editing capabilities?

@heminder The only


The only proprietary parts are Harrison's DSP. Everything else is open source, and in fact has already been included in Ardour's SVN server (Where appropriate of course, some of it wouldn't make sense to include in Ardour or would remove functionality from Ardour).


I do not believe that has been decided by Harrison at this point. I suspect it will depend in no small part on how well Mixbus does commercially.


At the pricing posted on the

At the pricing posted on the Harrison site (!!!) I'd buy a copy.... for Linux. Using Fedora 11/i686 with PlanetCCRMA FWIW.

The screenshot looks marvelous. If I had a Mac there would be a sale right now... :-) If there were a Linux binary, there'd be a sale right now.... Man, could I ever use this on the project I'm doing! But I guess having a binary of this for Linux by the middle of October is a pipe dream, and that's the deadline for getting this project out the door....

just to clarify a comment

just to clarify a comment from seablade about svn. the mixbus source code is all in ardour's SVN repository under its own branch. useful changes/fixes from the mixbus branch will propagate into 2.X and 3.X. all that is missing is the actual Harrison DSP code, which remains a closed source, dynamically loaded library.