my focal k2ps phase plugs are getting warm to the touch . should I back off on the gain or is this normal ?

 

Normal, heat is a natural byproduct of power production. All that power that is being turned into sound at the speaker, well there is going to be heat along with it. If your gains are set incorrectly, then yes, turn them down. Remember that a speaker must be allowed to cool or it will cook itself to death. If you have a large amount of power on tap, the heat being produced at the speaker may eventually damage the voice coils or voice coil former. There is heat that is being removed out of the backside of the speaker as well, just play the system loud in moderation only. Let things cool, your subs are probably nice and warm as well.