Like all Yamahas the global Master MIXER section will let you make those EQ adjustments to the entire KB output.
Remember working with a SUB is a whole new ballgame in the lower bass frequency response & adjustment EQ setups have to critically be made to each song. If you using two different systems you can also create a few USER EQ setups and choose which one you'll need before each gig depending on the system used. You can read all about it on Page 107 section 9 of your manual...

T4 manual