oh creativeguy, ive got a question for you

i've got the Klipch Promedia 4.1 speakers
http://www.klipsch.com/product/product.aspx?Cid=102

and Creative SB Live! 5.1 Platinum.
ive been using this combination for a few months now
and the rear speakers have been giving me a low whizzing sound since the day i bought the speakers
ive tried RMAing twice and still no improvements
i dont think there are any EM interference or anything strange happening to my soundcard but just wondering if this is soundcard related

btw, i used to have some cheaper 4.1 speakers with this card and there were no problems
but since these klipsch are more sensative and well tuned, im worried that its the card thats giving the noise


thanx in advance