myMix is a networked audio system which utilizes off-the-shelf 100Mbs networking hardware and standard CAT5 cables to distribute signals across the network. Signals can be injected onto the network via the local myMix inputs ( mic/line), IEX-16 input expanders ( line, ADAT), or a combination of both. Each signal gets a name assigned at it's input, which is used for identification, visible and available on all myMix units.
Audio channels on the network travel in pairs. A pair consists of the two inputs on a myMix, the odd-even inputs from IEX-16 (1 & 2, 3 & 4, 5 & 6, etc.) or a stereo mix from a myMix. Each network input pair can be configured as dual mono, stereo, or disabled from the network. When a pair is configured in stereo the audio comes in discreetly left and right and shows up as one named channel on the screen. A stereo pair still counts as two channels. Dual mono signals are two uniquely named, pan-able and mixable channels. While these signals always travel together, you have the choice of only selecting one member of the pair. It is important to keep in mind that although you have only selected one member of a pair on your mix screen, the pair counts as two channels against the 16 you can mix.
While each myMix can mix up to 16 channels, it can have access to many more. The current firmware supports 250 audio channel pairs ( = 500 audio channels), the actual quantity is depending on the switch. Typical for unmanaged switches are 16 (up to 22) channels, managed Fast Ethernet switches can handle 160. Each user can decide which 8 network pairs (or 16 channels) they want to mix. For instance, if you have 32 channels coming from the stage to the mixing console, you could have all 32 direct outputs routed to a pair of IEX-16L input expanders and use a third IEX-16L for 8 stereo sub-mixes like drums, vocals, guitars, keyboards, band, etc. for a total of 48 available network channels. The myMix philosophy is to help the musicians and not to overwhelm them with throwing 40+ channels at them. So each musician can select what they want to control individually and what they like to get as submix, e.g. the singer may have no interest in mixing the entire drum kit, but would rather have a stereo drum sub-mix and each additional vocalist independently, while the drummer wants full mixing control of the drum kit, but only wants a stereo sub-mix of guitars, vocals and keyboards. Download this 50-channel example here.
AVB is an open source protocol that is currently pending standards ratification by the IEEE. It requires the use of AVB switches ( or bridges). myMix uses a modified AVB protocol to operate with standard, easily available Ethernet switches. This also allows the integration of myMix in existing Ethernet networks. ( See Ethernet Switch Info for details).
More information on AVB: the AVnu Alliance is a great resource for AVB and its intended applications. The myMix firmware is updated by SD cards, so a myMix using a fully compliant AVB protocol is a future option.