I have a PV TKO115 combo, not sure of the age. Anyway, in the last few weeks of practice, the amp began to fart, crackle and make all kinds of bad sounds. Finally, I had to explore the problem. I was thinking dirty pots, cold solder joints and similar issues. As it turns out, it was the speaker itself, a BW1502 DT. In the magnet assembly, there is a screen to allow the voice coil to vent. Inside this screen is/was gray foam, apparently to filter the dust out of the vent air. The foam had disintegrated onto slimy gunk and had totally fouled the voice coil and rear of the dust cap on the cone. Upon removing the magnet assy from the basket, chunks of the foam remnants fell out of the voice coil. A complete cleaning of the voice coil and magnet gap was required. Alcohol appears to dissolve the gunk best. I strongly recommend that BW users remove this foam before it becomes an issue...TNX to all...
