Sound transmits via structure-bourne and air-bourne avenues. The structure-bourne is "addressed" by decoupling the vibrations of your speaker from exciting surfaces it contacts. The air-bourne is "addressed" by having sufficiently sealed mass (lots of mass) in all your room surfaces (including walls and ceiling, not just the floor).
If, as you describe, the conflict is situational to certain types of music...it is a really good possibility that the Subdude (or cousin Auralex GRAMMA) will reduce the structure-bourne transmission which MAY just do the trick.
I designed the GRAMMA/SubDude when I worked at Auralex Acoustics and co-hold the patent (although have no direct relationship to Auralex or that product...just so you won't think this is related to money). The affects on tone would have to be heard to know if detrimental...but I worked very hard on that product to make sure it really helped LF content be tighter and more articulate and not just less transmission.
I hope this helps. You can likely find an Auralex dealer with a return policy...I look forward to the update and good luck!
