Roland NE-1 Noise Eater

I use these under my hi-hat stand with my e-kit. They're a bit expensive, and can move a bit, especially with a lot of foot work, so you might need to adjust every so often. But, in conjunction with Noise Eaters for the pedals they stopped my downstairs neighbor from knocking at my door, so it's well recommended - I let myself practice even during late hours now, guiltless ;) Good investment considering they give me a much wider practice time window. You'll need a bunch of them plus the pedal NEs!