[Formerly YB-2]

Over the past few weeks I've made a couple of modifications to my speaker stands which affects the coupling to the floor (carpet over concrete).
First, added ~10# of media to each stand. The result is that the the speakers became more 'focused' and the bass tighter, faster & 'deeper' (last is very subjective).
After a week of listening and liking what I was hearing I added spikes with a base under them, which raised the speakers about 1.5". This resulted in the speakers becoming very focused to the point of beaming. All the music is now coming from each speaker rather than being spread across the sound stage. I'll be removing the spikes today.
Next up will be installing a couple of screws (once they get here) thru the stands to tighten the speakers to them (the stands are matched to the speakers so have matching holes). They speakers have been sitting on Herbie's pads (3, each. 2 at the front of the speaker & 1 centered at the rear) and will lock them down to the stands with the screws, which will compress the Herbie's pads a bit. Can't do without the pads as the finish is piano black and I do not wish to scratch even the bottom of the speakers.
Don't know if I'm coupling or decoupling (suspect the former) but am definitely hearing the results.