Last night I brought my Helix and in fact used the Spider V 240 as FRFR cabinet and I can tell you, amazing results!!!!!! instead of connecting in front of the amp you connect in the back of the Spider, that bypass the entire pre amp, effects, everything!!!!! The only thing that works is the volume! Use the AUX IN! The 240 version is a stereo version! from there you can send a L/R to the FOH, also you can use a splitter cable to send the signal from the Helix into a stereo 1/4"cable and send it to the Spider V. There is no way to go wrong guys, I got the same results connecting my Helix into a Line 6 FRFR monitor (L3M), exactly the same with the advantage to use the spider in small environments!