BookShelf Speakers Sound Muddy HELP


Hello,
I have a pair of Sonus Faber Concertos (not the domus). I also have a Vandersteen Sub. I notice that the bass coming from the speakers sounds a little muddy. The highest crossover setting on the Vandersteen is 80. Is there something I can do to tighten up the bass on the Concertos. Could this be a placement issue? I have the speakers on stands about 18 inches from the wall.
autodexr
How close is to close? If I brought them out any more then I would be less then 6 feet away?
Post removed 
Perhaps you expect too much from small speakers - I mean the bass and midrange come from the same small woofer. The idea of litlle speakers like this with gorgeous finish is mainly aesthetic and it is really a bit unfair to expect too much in terms of bass quality from a small ported box. Great speakers but you can't "have your cake and eat it" so to speak.
Would I gain a benefit by buying an external crossover and cross over at a lower level 65 as opposed to 80?
is your room treated, can you listen to these speakers in a different room and hear same muddiness? i dunno these spkrs. but if you are still driving them full range plus adding a sub at 80kz then heck yeah you got a chance of having excess crap at that octave. have you always noticed this and are you driving them hard? just a few thoughts. if you are x-ing over at 80, to me that is too high for most non cavernous rooms unless you have tiny monitors