Thank you Biggles,Before you shell out cash and buy additional kit you may find that simply repositioning the L & R speakers off the isolation racks and place them level with your head when you are playing the keyboard makes a difference, also where they are positioned relative to the wall behind them will make a considerable difference.
At the rear of your speakers you should find the switches that I was referring to, try adjusting them both where they are and when you have the speakers at head height.
Btw, the Yamaha Manual for your speakers states that the L & R pair should be positioned at least 1.5m from a wall or room corner.
I am going to get some speaker stands and raise them off the floor. I actually have my keyboard(s) set up in my office at the mo. I live in Phoenix and the best room of the house (sunroom) does not have air conditioning at the moment. It is still 100 + here so to hot in there!. "Unfortunately the keyboard set up i have right not is not worthy of putting in the main living room" (actual words from my wife lol) but that is understandable... its not like owning a piano or organ so at the moment i am a bit restricted space wise I have already bought the equalizer ect... so in conjunction with your great tips and the assistance from Gary i think i will have a much better set up!!.
You are all great on here... sometimes forums can be a bit hit or miss but already you guys have helped me so much so thank you!
Once i get my set up and running i will post a photo!