I ended up returning them, they did tighten up the bass, but the treble was harsher and more fatiguing... Didn’t work for me, difficult to set up too, the design is funky and it can be tricky to get them tight, level, and facing the direction they tell you is best in the set up guide... too pricey also, its just sorbothane with some made in china milled parts... I went back to the regular floor spikes, but I found some carbon fiber floor spike protectors on Amazon, Viborg audio I think was the brand, only cost like $30, I cut little heavy duty rubber pieces under those I had in the garage and it sounded better than the Isoacoustics in my setup