Firewire streams on a StudioLive mixer are called "Firewire Returns" according to the Software Library Reference Manual, page 9 section 2.5. These firewire returns according to Section 6.6 of the StudioLive Hardware Reference Manual, showing the Block diagram of how things are routed through the mixer, shows that firewire returns come separate from the input channel's converter over firewire.
Therefore, Firewire streams can be recorded by busing to other outputs being recorded on a mixer, but not through individual input channels, as expressed here.
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