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Revision as of 22:49, 22 October 2008 by Nando (Talk | contribs) (Host Computer)

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A fully-extensible software-based dedicated mixing console emulation.


What do we want to do when we get to the Studio that houses the OpenMixer system:

  • login to the studio workstation, press a button in the UI that says "Workstation" and have all 24 channels of the soundcard connected to all 24 speakers, control overall volume with a fader labeled "Master"
  • walk to the dvd player, insert a DVD disk, press a button in the UI that says "DVD" and have the DVD play in 5.1, control overall volume with a fader labeled "Master"
  • connect a laptop for stereo playback by connecting to a 1/8" plug, press a button in the UI that says "Laptop" and have stereo playback properly routed, control overall volume with a fader labeled "Master"
  • connect a laptop for 8 channel playback by connecting multiple outputs to 1/4" plugs, press a button in the UI that says "Laptop8" and have 8 channels routed to the mid 8 channel speaker ring, control overall volume with a fader labeled "Master"


The OpenMixer software runs in a dedicated fanless computer. Zalman has discontinued their TNN300 and TNN500AF products so we have to look for other options.

Host Computer

Options for fanless computers:

TNN500 case


TNN300 case

Discontinued but still available so it is an option. Advantages: a product we know and works very well. Disadvantages: 70W max power for the CPU so no quad core options, form factor could be smaller (we need something "hidden").

mCubed case

Review of a computer using the same case:

Logisys computers

Other fanless small computers

Audio Interface

The audio input and output is controlled by an RME HDSP Madi PCI card ( which provides 64 inputs, 64 outputs, MIDI i/o, work clock i/o, etc. It uses up 2 back panel slots but is inserted into one PCI slot. Another option is the RME PCIe Madi PCI Express card ( PCI Express card (same capabilities, different bus).

The MADI output is split into ADAT outputs using the RME ADI-648 ADAT/MADI converter ( (we get 8 ADAT pipes from it). The ADAT pipes can be connected directly to other computers or equipment, or go through ADAT D/A and/or A/D converters to connect to analog equipment.

Control Surface

The simplest alternative is to use a USB (MIDI through USB) fader box. The Behringer BCF-2000 ( is an inexpensive 8 fader box that could be used as the basic control interface. The Behringer BCR-2000 ( can be used as an auxilliary control interface to do channel assignments. All the interaction between the user and OpenMixer would happen through that interface.


The OpenMixer computer boots into the control program. At least in the first stage it does not even have a monitor, keyboard and mouse for user interaction (just the control surfaces outlined above).

The software would consist of several separate processes that can be started from runlevel 3 (or runlevel 5 is a GUI and X are used).

  • control program
  • jackmp server
  • jacktrip server