FX multi in out routing

Hi, I have a question concerning FX in and out routing in Reaper, because I can't find the answer in Francis' documentation. I have the feeling that the routing works as follows, what doesn't feel consequent for me: When I am routing channels 1+2 into an effect with outputs to 3+4. The original signal will now still be on channel 1+2 after this effect plus on 3+4 the processed signal, right? Now what I don't understand: When I am Routing channels 3+4 with another effect back to channel 1+2, the original channel 1+2 has disappeared behind this effect. Right? That means for me that I can not use for example IX/Mixer_8xS to split the signal of channels 1+2 to several channels in order to do parallel processing, as the original signal will always stay on channel 1+2 not reagarding what level I chose in the mixer. Or lets say I could use the mixer to split the signal, but can not use channels 1+2. Am I right? Where are these things like FX signal routing documented? What is a good way to do parallel FX processing in Reaper? Thanks and regards, Phil

Try right clicking on the I/O button of the sending track and un-check "Master send". This option is also located in upper left of the Routing dialog window.., labeled "Master/parent send".

Wow, thanks everybody for these very good answers that explain everything perfectly and show me, that my understanding was correct. But to be honest, I have spent some very frustrating moments finding this out by try and error before I have started this thread to prove that my assumptions are right. This should definitely be explained in the manual or somewhere in Reaper, for example by roll over texts or something like that. Unfortunately the manual shows only one block for "Track FX Chain" in the track signal flow chart (5.20). This boxed could be perfectly explained by DarkStar's scheme. This would prevent other users to be frustrated, too. I don't know where this should be addressed correctly... Thanks again everybody.

^^^^ User Guide update; Already in progress. :)

Great explains all around. I just wish someone would make a tutorial where they used it on an effect that had, let's say, 8 channel possibilities, and how it would be routed, that would keep 1/2 dry, and the other channels effected and all sent back somewhere, then to Master track. DR