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

@paul: is this done in a

@paul: is this done in a generic way so that you can specify one or more plugins to have their UI inline in a mixer channel? For example I'd quite like to have a trim (simple amplifier), delay (for time alignment) and triple band EQ on each channel. This would be quite a cool feature! With LV2 I imagine you could have an extension for "channel strip UI" which would be designed to fit in the channel strip. And then a button to launch the full UI. Obviously this can all be done using normal LADSPA plugins, the advantage is that you now can tweak the plugins directly without opening their UI windows.

Well, I've put my money where

Well, I've put my money where my mouth is. Even though I don't currently have a Mac with a high enough rev of Mac OS X, I bought a copy, if nothing else, to help support this effort. I have a PPC Mac running 10.3 available to me; perhaps it's updateable to something later.

@nickmurtagh At the moment it


At the moment it requires modifications to Ardour's source code itself in order to provide that level of integration, sorry. I have brought up a few suggestions(Not sure if Paul was there for them or not) in the same line of thought you are thinking of though;)


One more comment: The Mixbus

One more comment:

The Mixbus Quick Start PDF is quite a good introduction to Ardour in general, and a great, quality read.

I bought mixbus and it is

I bought mixbus and it is really awesome!! I have been using SawStudio on a PC for about 4 years and was looking for something sonically equivalent for my mixing style on mac. Thanks guys for all the great work on this app!!!

Great job to all involved! I

Great job to all involved!

I am crossing my fingers that a Linux version will be made available at the same price.

@nickmurtagh: there's quite a

@nickmurtagh: there's quite a bit more going on in mixbus that you can see from the GUI. i've alluded to that in the news item - the harrison plugin does some unconventional things (though entirely "legal" from an API perspective) for a LADSPA plugin.

i don't intend to do any work on the 2.X series to make it easier to have "plugin GUIs inline", but its certainly a long term goal for the 3.X series to move toward something a bit closer to what mixbus is doing now, from a GUI perspective at least. i don't think that regular ardour will ever get close to what mixbus is presenting, but certainly being able to present "a bit more detail" for basic plugins would be desirable.

hi paul, if i understand your

hi paul,
if i understand your posting right, its possible to compile this branche (mixbus) under linux.
but to get it working you need something like dynamic link libraries which are not included as binary or as source code? right? if yes, is it possible to get this libraries.
e.g by buying the osx version of mixbus.

greetings wolke

i just get the mixbus branch compiled on my debian linux box. whatever it looks like that i need a file called "harrison_channelstrip.so".

where can i official get this file?

you cannot get this file.

you cannot get this file. there will be an official linux release of mixbus when we determine how to distribute it.

ok, thanks. sounds good. i

ok, thanks.
sounds good. i hope your involved into this project :-). this is a good place for a part of commercial closed software in this awesome daw.
greetings wolke

Any idea when Mixbus will

Any idea when Mixbus will working with SL10.6.1? I have a new MBP and see it is not compatible.

Hi Paul, This may have been

Hi Paul,

This may have been suggested before, but for something like Ardour, I don't see what's wrong with a static binary distrobution. I use Blender on Ubuntu and never go near the repos to get it. Tools like Blender and Ardour, are large specialist tools that I think benefit from that distrobution method.

Have you checked out the Blender packages ( http://www.blender.org/download/get-blender/ )? Are there reasons for not having statically linked binaries? I'm genuinely curious and I can't find anything from searching the site.

Is the multichannel support

Is the multichannel support gone in this Ardour/Mixbus? I only see mention of stereo. Will it be possible to do ambisonics beside stereo (meaning inserting multichannel LADSPA plugins)? If it does then I'll be considering buying it.



@philip8888 We will be


We will be looking to support it after JackOSX supports Snow Leopard, but it will obviously need to be tested first.

@Max Littlemore

That is one possibility that is being looked at to my knowledge yes. There are reasons not to have them, for instance the dependency on the static linked version of specific libs means that you can have multiple versions of the libs floating around, not all of them up to date.


Mixbus is Stereo only.


@Max Littlemore: Blender

@Max Littlemore: Blender doesn't use GTK. GTK can be built as a static lib but continues to use dynamic (run time) loading of various components (such as image handlers). This complicates a "static" build somewhat.

I bought Mixbus, coming from

I bought Mixbus, coming from a background where I really had no idea about Ardour, and think it sounds great! I'm trying to spread the good word across all the forums I stop at.

I would really, really like to see Mixbus continue to grow, and see Harrison keep Mixbus alive along the development of Ardour. I realize that this depends on the commercial success. I have a few comments on what I've perceived so far, based on my own experience.

As an Ableton user, I was first exposed to Mixbus, and thus Ardour, through the Live Forum. There, I found the thread at gearslutz. Ultimately, I bought Mixbus based on: 1) the positive feedback on gearsultz; and 2) the introductory pricing. However, as a reflection on Harrison, I thought the thread was a mixed bag. In particular, I saw the same question being repeated and unanswered by Harrison representatives. These questions concerned how the Mixbus achieved its allege improved sound. While I was able to discern the reasons, it seemed that many could not, and that these took a disproportionally negative stance to what I otherwise saw as a great product.

My personal experience involved setting up Mixbus with Live, a process I am still refining. While I was able to initially figure out a work flow on my own, I easily saw how others could be extremely put off by the process. However, I must emphasize that Mixbus and Ardour have not crashed on me as of yet.

Thus, in my opinion, the two biggest obstacles I can see so far to Harrison and Ardours continued success with the Mixbus involves two issues: 1) a clear, streamlined explanation of why and how Mixbus sounds "better" than other DAWs; and 2) clear and concise explanations of the various ways to route audio and midi from one application into Mixbus.

To give an example in outline form:

1. Why Mixbus sounds better - Harrison's Algorithms developed from 30 years of experience
A. At the summing level - what's the difference between the way most DAW's sum and Mixbus?
B. EQ's - exactly what are they based on?
C. Compression/Limiting - same with EQ's
D. the 4 Mixbusses - clearly explain their advantages and uses

2. Routing Audio - the Flexibility of JackOSX
A. Setting up jack - a simplified version of what is presented in the quickstart guide
B. Routing application outputs --> I'm still figuring this one out
C. using the Jack audio unit / vst plugin --> the method I currently use

3. Routing Midi
A. MTC sync
B. Midi Patchbay

All in 2 pages, tops. I had to search through forums to find out how to do everything needed to do, and I'm still in the process of figuring somethings out. But to attract new users the sound difference of Mixbus needs to be clearly spelled, imho, and the integration aspect needs to be presented in a way that makes people realize how powerful it really is. I'm excited now to be using Jack, and equally excited to have an app which can fully take advantage of it. But this aspect isn't really being presented in the clearest way, in my opinion.

Like I mentioned regarding the gearslutz thread, there is so much noise that its hard to really hear what Ardour and Harrison are saying with this product. I will end with the caveat that what I am suggesting may not be needed by more season engineers and producers, as I am more of an artist. However, a lot of the negative and critical comments were being made by, it seemed to me, much more seasoned and veteran engineers.

In the end, a concise explanation highlighting the main factors contributing to the Mixbus sound and clear step by step instructions for integrating Mix Bus with the major DAWS may be able to get people to take that $80 plunge. If they're like me and most of the other happy users, it will be well worth it!

Mixbus sounds great bought it

Mixbus sounds great bought it last night and just a few hours behind the wheel well what can I say it´s good. Seems there´s no midi though but I guess there´s way around that one too via Logic or something. Playing with mac osx86 on an old Dell singlecore 3,2 Ghz just for fun and it even runs pretty ok on that one too.

Mixbus is a superb product,

Mixbus is a superb product, and I believe it really does what it says on the tin!! :) Many thanks to all who worked on this great product.

I tested Mixbus by importing WAV format source audio files from a recent mixing project. The most noticeable thing about using Mixbus is that the audio required far less 'tweaking' to achieve a great sounding mix compared to the industry standard DAW I had previously used for this mixing project. I was also able to achieve this without using any additional EQ or dynamics processing plugins, only using Mixbus EQ. I also found that I did not need to use nearly as much compression to allow all the instruments to have space and presence in the mix - only using it to even out the bass guitar performance and for parallel compression on the drums.

I had the memorable pleasure of mixing and assisting on a Harrison 32 Series console in the mid-80's for a couple of projects and Mixbus really reminds me of those times. IMO the Harrsion 32 Series was one of the most 'musical' consoles I mixed or assisted on. I very much hope that Mixbus is a great success.

I will be using Mixbus as much as possible for projects going forward. I was blown away by the sound, the resolution and the detail/clarity of the audio. I also very much like the 'de-cluttered' interface and the fact that the input channel and mix bus channel strips have only 'essential' features and no frills. Mixbus sounds and feels to me like a real console.

So far Mixbus itself seems stable on Mac OS X.6.1 (MBP Dual-Core Intel Xeon) using the latest version of JACK.

It's a real pleasure to use! :)

hey all. this looks great! i

hey all. this looks great! i just hope that the code specific to mixbus (not the prop. libs, i mean the gpl wrapper code) can be ported to the 3.0 codebase. that way (i hope), one could purchase this version and use the libraries in the modified 3.0 version. also, if those parts are abstracted, perhaps there would be scope for plugging in other plugins (eq/comps etc) in the same way.

i have to admit i have been away from ardour a bit (still a subscriber though) as i have needed to use features with midi/loops etc for projects that ardour doesn't do at the moment, but watching that youtube video makes me wish i could come back 'home'. if this was made to work with 3.0's midi stuff, i would be very close to heaven haha

i haven't looked at the price yet, but may get it anyway, as a test. if one purchases the osx version, will they be entitled to the linux version (when it is released), or will they have to be purchased separately?

update: just purchased a copy (although i haven't booted into osx to test it. i still use linux day to day and have no intention of changing). also can i just say i love seeing 'real' looking faders again? i understand the reasoning behind the ribbon-like ardour ones, but this just feels more natural to me. maybe make them an option ('use natural faders'/'use ribbon faders')?

I'm using Ubuntu Studio linux

I'm using Ubuntu Studio linux and....I need mixbus for audio production in ardour. NEED.

I'm currently using JAMin with Ardour, but it's just not the same as having a compressor/EQ plugin in Ardour. I need it.

If there's anything i can do to help with developing an EQ/compressor plugin for Ardour, please let me know. I'll do whatever i can to help out with this. kimsynghyun7@jinbo.net

@g-raf Have a look

@g-raf Have a look here:


Compressor, EQ plugins - everything you need - especially:


I would also love to have

I would also love to have ardour/mixbus on linux. Would be nice.
And those linuxdsp plugins too.

When the new laptop and the new audio interface arrives, life will be good. :)

is really good work! Thnks

is really good work! Thnks for everything.



MIXBUS 1.3 IS Out Baby!!!!

New Mixbus Version 1.3 released August 11, 2010

Please ! Tell me that youŕe

Please ! Tell me that youŕe working with care in a linux version of Mixbus, I will be waiting for this day.

A while ago someone asked

A while ago someone asked about Mixbus based on A3, and the answer was something like... totally hypothetical and depended on how well is 2.X received by the world....

Now i've seen a few "very good" LV2 plugins that leaves me very little to nothing to envy to pro plugins on other platforms (ozone for example for windows or mac)... so now it seems with A3a3 that low-cost / high flexibility and performance / home recording is getting very close to be true in GNU/Linux.... to that you add a great low-cost project like Mixbus....

so my question is: does Mixbus based on A3 keeps being absolutely hypothetical or would that change? a Mixbus addition to A3 would be a great improvement over an already greatly improved DAW.

@fernesto: I think its

@fernesto: I think its extremely important that you understand two things clearly. Ardour 3 is still at the alpha stages, and Mixbus is still undergoing its own development based on the Ardour 2 codebase. Even with all the will in the world to eventually release a version of Mixbus based on Ardour 3, Harrison still could not feasibly do this in any near-term time range. They know that there are audio related features in Ardour 3 that will be a good complement to Mixbus' own features. That doesn't mean that it makes any sense for them to start working on an Ardour 3 version when Ardour 3 has not even reached a beta release. I think its rather likely that in the long term some version of Mixbus will be released that uses Ardour 3 as the starting point. But its not likely to happen for quite some time. For myself, I consider the Ardour 2 codebase to be more or less a dead end, so I will certainly welcome it whenever Harrison decide to switch. But Ardour 2 is also far better tested and known, and therefore I would not attempt to hurry Harrison into that decision.

Nifty-looking product... and

Nifty-looking product... and highly cool for the company (i.e., Paul) to engage with the Ardour forum. Impressed!

Just a couple of questions... was this 30-year mature DSP code intended to run on... an actual DSP? I.e., on a hardware DSP processor running a softcore or else a hardcore execution environment? If so, is a virtual machine layer also part of the MixBus package... i.e., some hardware emulator for the "actual Harrison DSP code" to run on? If so, is this emulation layer Harrison-owned, or licensed from a third party? Finally, is it understood at present what level of license compatibility exists between any DSP execution environments involved, and the Linux kernel?

Sorry for such intrusive questions. But your comments about differences between distributions made me wonder whether legal rather than technical challenges may be slowing down a release compatible with open source.



@hkingman Keep in mind I


Keep in mind I don't work for Harrison(And neither does Paul by the way)... but I think you missed something. The majority of the code for Mixbus IS open source, it is Ardour, with closed source parts in the form of LADSPA/DSP plugins that are integrated into the interface. You can check out most of the code for Mixbus in Ardour's SVN repo in fact, but you won't be able to do much with it as it doesn't have the closed source DSP in it obviously.

In as far as how the DSP is implemented, having used it for some time I seriously doubt that there is any VM/emulation environment. All this code was written from scratch and compiled to run on x86, which if you look at some of Harrison's existing product line, that shouldn't be to surprising either.


Yup I think this would be a

Yup I think this would be a great idea. Btw, really love this product !!!