Sonics of Hooking Up Multiple Outputs on Preamp

First post and I really appreciate all of the knowledge shared!  My system consists of a Krell KSL line stage, Krell KST-100 amp powering Kef 105.2 speakers.  I have 2 SVS SD-12 sealed subs that I purchased for home theater duty but I until that system gets built, I'd like to add them in my 2 channel audio system.  The KSL has 2 output pairs (balanced and single ended) that can output simultaneously.  I'm currently using the balanced outs to my KST amp.  The SVS subs have standard rca inputs; no high level speaker inputs/outs.  I talked with an SVS rep and he suggested running out of the KSL's single ended RCA (left channel out to left channel in on sub1; and right channel out to right channel in on sub2).  I've read some of the posts here about impedance matching and other issues.  According to the specs that I have the KST amp has an input impedance of 47K; the SVS subs have 20K input impedance each; and according to Stereophile's review of the KSL it has an output impedance of 11 ohms.  I have my original KSL manual and oddly enough it lists no specs.  Do you think this is the optimal way to integrate these subs or should I be thinking about a speaker to line level converter and go off a set of posts from the KST amp? 
I would also be running the KEF's at full range.  Thanks for any assistance!
Your numbers seem OK to do it. If you want to up the input impedance of the sub to say... 100K to 500K just get a buffer (tube or even better solid state) The Burson Buffer is excellent for this. Insert it between the pre amp and sub.
Thanks Koestner.  I will look that up.  I gave Krell a call and they definitely recommend to go low level preamp out to subs.