Ableton Audio Interface to PA system - sounds muddy and not clear vs. recording.

Hello all,

I have a basic VST/audio interface setup question. Currently, I'm using a hardware synth as my main keyboard but would like to switch to using software synths as my main keyboard. The problem I have right now is that whenever I play the software synth sounds, it sounds muddy and not clear. When I'm recording then it sounds fine (it also sounds good through the headphones), but when it goes to the PA system it sounds weak. My setup is as follows -

MacBook Pro Ableton Live 9 Focusrite Scarlett 2i2 Novation Launchkey 61 USB Keyboard Controller TRS cable from audio interface to PA system

Any help is very appreciated. Thank you!