i have owned them both and a and b them side by side, the 9 kappa produces more bass that fills a larger room, but the ren 90's bass is tighter and more accurate and everything elese above the woofers is much better on the ren 90's, also the rens cabinet is built much better, the ren's are more musically accurate, the sound from the kappa 9 is nice but when compared to the ren 90 it's not even close, if you want the more musically accurate speaker the rens win, you can't beat the sound of the newer high energy emit's and emim's, also after comparing the two the kappa 9's mid bass coupler sticks out like a sore thumb and to me adds it's own coloration and if i had to describe the sound it makes, it sounds like the sound a plastic milk carton makes when you pluck it with your finger and you only really notice it when comparing the two speakers side by side, boy it's annoying, to me the ren 90's where the clear winner, that said, i gave my brother the kappa 9's
