I've got mark 1 kef eggs with a psw2000. I'm looking at replacing the sub and have found a rel stadium 1. I have two questions this sub has a frequency response of 20hz- 120hz whereas the kef sub is 35hz - 150hz. Will the the rel have problems integrating with the eggs? The rel only has high level XLR inputs only so will be connected via the front speaker output from the amp will this cause problems?