Finally found time to try it. Seemed to make the situation a little worse. I had to turn the receiver volume down to -34db before it would stop rattleing. At that level i could hardly hear the movie. Finally arrived at setting the sub at -10DB on the recever (its lowest level) and setting it at 10 to 12 on the sub. Still small amount of vibration at the peaks.
But this greatly reduced the lows.
Will start saving for another sub, as that seems to be the only answer. This could be thread of what sub to buy ?
Thanks for your trouble and time bridgeman.
Much appreciated.