Every little change in a Roland style pad construction (most in a snare!!) has effect on triggering. And every part you change is correlated to another part: cone, piezo (material, shape,protrusion),mounting plate (weight, shape), silent washers, double sided tape (material, shape, diameter). Everything of these elements affect the signal (waveform, that must be the more sinusoidal you can) and the crosstalk among the sensors. It's not so easy to manufacture a pad that gives a real drum feeling!!
That's one of the reason why Roland makes them in japan and not in china (not the brains, the keys and other stuff). And "partially" the reason of their unbelievably high price (the other part is on patents, profit and alike)!!
I figured this out cause i had to re-build my snare completly to rich the goal. Maylord knows the issues, he saw my pics.
So please post some pictures, maybe we can help you
MD can do that! It's only a matter of time...