buzz from speaker..

I had a similar problem. Try swapping the speaker cables and see if it is truly the speaker, or something up the line. If the buzz goes to the other speaker, you know it is not the speaker. Then you have to start switching interconnects and isolate the problem to the component causing the buzz.
For me, it was the amplifier, which I had repaired and the buzz was eliminated.

one possible cause may be the dustcap. If the glue has failed it may cause a "buzzing" or "farting" sound at certain frequencies. -jz

I may be way off base with this, but I would first check and make sure your driver screws are tight. If they have worked loose, it could cause such a noise from vibration.

If that isn't it, then try others suggestions. But I would start out with the ultra simple stuff.

What are dustcaps ?

The sound that I am getting is at certain frequencies, so I am sure it is not due to any source amp, pre, etc. I checked the speaker cones all for rips or torn dust caps and the screws to all drivers and all are fine. The woofer cones are all new and I was wondering could it have gone bad, and could the magnet have lost its strength, or even loosened on the back of the driver? I thank you all again for your suggestions.