Those of us that have Peavey cabs with the 18" BW. If your BW speaker starts to get noisy and/or muted sounding. This may be due to a known issue with the older BW speakers.
Peavey used a black foam plastic in the airspace at the center if the magnet assembly. That foam plastic tends to deteriorate and crumble in the 20 or so years since manufacture and the fragments can find their way into the voice coil gap and interfere with the movement of the VC. Mine got so bad during an outside gig that the cone became stuck in place. (after the coil cooled off).
I took the speaker out to see what happened. The magnet assembly comes off the spider on these by removing the 3 allen bolts and gently prying the magnet assembly off. I found that the voice coil dome was filled with black plastic flakes and some were melted onto the coil itself like tar.
I gently removed all the plastic(tar) gently working it loose with my fingernail. But, there was still lots of bits sticking to the VC gap which I scraped off. Then, I used some masking tape doubled up with the sticky side out to clean off all the debris and metal bits sticking the the VC gap. (learned about that trick from reconing sites)
Now the speaker works as good as new.
