[Laurence Payne]

On Mon, 14 Jan 2008 07:16:19 -0800 (PST), EADGBE
wrote:

I am suspecting that maybe the spider is
out of round or off-center, or maybe the voice
coil is off-center.

What can I do to further diagnose, and then fix,
this annoying problem?

One easy thing to try is to mount the speaker the other way up.
Otherwise get it re-coned. This may or may not be cost-effective.