Not really, no. Only the most advanced surround sound systems support proper vertical panning (it would be called tilting I suppose). All standard systems have at all or at least the crucial speakers1 on the same vertical level, so there's not really any elevation information present. Any perceived top-bottom separation has indirect, psycho- or room-acoustical reasons.
In your case, the most likely reason is simply that your monitors have tweeters which are in fact located at the top of the speaker cabinets, so the high-frequency components do come from higher up than the bass- and midrange. Not much you can do about that, it's just specific to your listening conditions. You could somewhat mitigate the effect by giving the bass instruments lots of high-frequency components (by treble boosting and/or unsmoothened distortion), but this would obviously affect the whole mix very strongly. And in other listening environments, the elevation effect would work out completely different anyway, because the tweeters don't introduce that kind of spatial separation in the first place.
In general, you can employ some more subtle methods to virtually place instruments in the mix in other ways than just left-right. Obviously, reverb setup as well as compression has a lot of say in how "far away" an instrument appears to be. But that's about the only thing you can say easily, more sophisticated fine-graining of space involves lots of experience-driven and rather heuristic tuning of all mix parameters.
Some sounds are just associated to come from above or below by cliché, so if you somehow manage to get it somewhat "organ-like", "stomp-like" or whatever you might achieve some kind of pseudo-tilting through that. But there isn't one recipe to do something like that, you can at best just trial-and error yourself.
Subwoofers are often placed on floor-level, but it's generally impossible to localise bass frequencies very accurately
. Even for low-pitched instruments, we still take the location information mostly from their midrange sound components, so unless you have very small satellites and take a lot of the midrange from the sub[s] as well, this is unlikely to have much influence.