Phase Plug Fun

[Feanor]

I know what I hear and that's enough for me. Moving mass? The plugs are not glued but held in place magnetically. They do not contact the cones or voice coil. The higher end full rangers like the whizzer cone Lowthers use huge wooden phase plugs.

Phase Plugs

Are you saying that your phase plugs are not attached to any moving part of the driver? I can imaging that this might be the case but you aren't making it clear.

With the dust cap, which is usually attached to the cone, removed you might expose what I believe is called the "pole piece". The latter is a fixed part of the driver; if your phase plug is attached to the pole piece, then it won't move with the cone or whizzer.