mounting Yamaha D-10 triggers

I made DIY mesh heads and am trying to find the best way to mount the D-10's. Pientech has the set up in the middle of the drum mounted on the cross brace spanning the diameter of the drum. Their trigger has a foam cone on it between the trig and bottom of the head. When I mounted mine that way ( using varing thickness of foam ) the hardest hits are all that it will reconize. If I just tape the triggers to the mesh head it works ok, but I'm wondering if the D-10 are low grade sensors and I should get some piezo transducers and start over. HOW are Yamaha D-10 Sopposed to be mounted? What is suggested by the company as opposed as to what " really " works. I'm using an Alesis D-5 Mod. Any suggestions would be great! Thanks in advance for any help. zion