Side effects
An effects rack that several lanes pass through, one at a time, without ever being summed.
A send bus mixes what it receives. A side effect lane does not. It is an effects rack beside the send strips that a lane routes through: the lane adds a Side effect device to its own rack, points it at the side effect lane, and its signal leaves the rack at that slot, passes through the side effect lane's devices, and comes back to the same slot to continue. Several lanes through one side effect lane are separate streams: each gets its own copy of the rack, all copies share one set of controls. So one compressor setting applies to three parts, tuned once, and each part is compressed on its own.




Sidechain
A device in a side effect rack can listen to a lane other than the one it is processing. The factory compressor's detector has a Sidechain In, and on the rack you pick which routed lane keys it, with the option to process the source as well. A bass line ducked by the kick is two lanes through one side effect lane and one menu choice. Keys arrive on the same sample as the audio they key.


Groups and send buses can route through a side effect lane too, and a side effect lane's rack has its own automation and modulation like any other.