It's not masonry. It is a wood frame wall with gypsum board surface; standard drwall as we call it here. But it should be OK. If not I wil alter them. Thanks.
Steve,
I am in the US with the same standard timber / drywall construction and do prefer the freestanding XO (especially now I am using them very far away from the back wall). When I had passive Kan's I could never get them to work well, active for some reason worked great. For me speakers designed for placement against a rear wall just don't seem to work as well in timber frame constructions.