It's impossible to get a tone on the headphones that will sound exact on the pa.. But I would recommend using the least bit of delay , reverts , dimension or such effects when creating tones on the headphones and then quickly tuning them on the pa,. I have bought a pair of powered studio monitor speakers.. And in my opinion the tones created using them sound same on the pa. I only sometimes have to tweak the highs later on.. But it's much easier this way then using headphones which I started out with :-P