Getting a clean sound when playing live

I was wondering if anyone has some advice on how to get a clean, crisp sound from Ableton when playing live. I have been using Ableton for years as the main part of a hybrid DJ set where we play our mastered tracks with a few synths and drum machines over top. Whenever we play, on good systems or bad (sounds worse on bad systems, obviously) we struggle with getting a clean, punchy sound. After having a DJ play from CDJs when we start, it always sounds a bit muffled and muddy.
We play our tracks (most of which were professionally mastered) warped mostly with Complex Pro mode, although sometimes Tone or Re-Pitch sounds better. The audio tracks are set at about -6 dB to prevent any redlining and there is nothing on the Master channel. We are using an old Motu Ultralite Mk1 intrerface which is set to 0dB (unity) on the output , but I have also tried my UAD twin from the studio.
Does anyone who uses Ableton in a similar way have any tips? Is there something I have missed in the audio settings all these years?