So you're saying the spider is deflecting waves from the bottom of the cone?
Nah man, Spider deflection is how much a spider will let the coil rock side to side.
If it moves side to side it will hit metal, and its the only way you will get a 'clanking' noise unless the cone is hitting the spider landing itself...
That's why very very very few people use the large diameter spiders because it will allow it to rock, when the coil rocks with power on it it'l either short the coil out and fry it, or it'l make loud clanking metallic noises.
You can have MUCH more linear travel with a 8.5" spider with taller rolls, then a 10 or 12" spider with shorter rolls.
Easy But VERY crude example, Take a dollar bill hold it horozontally so you can read it properly left to right, and push your hands together. See how easy that is?
Now flip that same dollar bill 1/4 of a turn and do the same thing, you should beable to tell the difference in force needed to apply to make the dollar bill 'deflect' or move.
Point being...Spiders are ideally designed to be 100% linear in forward and rearword travel, and have no side to side travel...