when you have such great hardware gear, why you wanna just mix itb and with ableton?
my sugestions based on my experience playing live shows is:
- mix inside the hardwar units - most elektrons have an audio in for chaining / mixing
- or buy an analog mixing desk (or ask the promoter to rent it) - ofcourse no Behringer
which may gives you some inserts for hooking up a smal master compressor like RLNC - Really Nice Compressor
I bought a small Yamaha MG10 mixing desk to send 3 Elektrons through it and a reverb and a Korg Volca Bass. This is way more fun and better sounding then in mixing in the box with Ableton (which I´ve also done in the past). Depending on the OP amp on the mixing desk, it also will colour your sound a bit and maybe will give you some saturation or slightly compression. You even can use the Lowcuts on the mixing desk. The Yamaha is around 150 EUR and not bigger then a 13" macbook — so it´s a steal for a small liveset up and you can integrate some hardware fx like a reverb and / or delay and / or phaser/flanger.
But if you still wanna mix inside the box with Ableton … I would suggest run it at least 48khz (or higher). When you use compressors on single tracks, go with opto compressors / LA2 emulations - or set attack 10ms - 50ms and release to taste. You can set attacks smaller like 5 ms - but that will cut you the transients on drums etc. Ratio I would go with 2:1 to 2.5:1 and try soft or hardknee. You also can experiment with peak and rms … but the opto style compressor looking more for rms. Gain reduction 1 - 2 db. And on the master I would go with an ssl bus compressor style like ableton bus compressor which emulates the behaviour of the ssl bus compressor … attack 30ms (longes), release 100ms (or it says 0.1) ( shortest), Ration 2:1 or 4:1 - it has different knees! Gain reduction max. 1db
Just don´t push it to the limits inside the box. The soundguy can always turn up the PA if your signal is good. But when it is distorted or clipped from inside the box it would sound shitty also on the best sound system.