About to go and collect my new centre speaker, a wharfedale 9cs. I've checked the brochure and it's 89db sensitivity, whereas the 9.1s I have for the rest of the system are 86. Does this mean that on the receiver, I should set the centre to -3db to even it up with the rest, or is it ok on 0db, like all the others? I don't want the centre to overpower the rest of my setup. Am I worrying about nothing..I haven't even plugged it in yet..?!