I'll try to attach a sound file. Meanwhile: My 6G2 started to buzz, especially on certain notes. After much tweaking, testing, and tightening, tho, I found out this new buzz was from the speaker — a used ALK1028. It does it sitting on the floor, in different rooms, with different guitars and cables, and it does it moved to another amp and cab. Frankly, I’m glad it’s not the chassis (a loose wire behind the board?) or the cab ($$$). So in the recording you’ll see it is almost as loud (and a lot more prominent) on faint harmonics as on hard-hit bass notes. (It helps to play the file loud through good speakers). Now I can’t hear an *obvious* rub when I deflect the cone with my thumbs. The fact it's there even with faint harmonics, and that it's louder at certain frequencies, must say something. Is it possible to have a voice coil problem and not hear a rub when deflecting the cone? I wonder about a chunk of loose glue or paper in the voice coil gap. So I read the late great Ted Weber's Q&A on a possible fix (quoted below). He includes re-forming the voice coil, which sounds, um, tedious if not risky. But could I just cut out the dustcap like he does and try to blow out any debris? Ted said: "Lay the speaker on its back with the cone facing up and with a scalpel, carefully cut out the dustcap, leaving about 1/16″ of dustcap where it is glued to the cone. This is important because the voice coil wires pass through this point and you want to make sure you don’t cut them. Next, use a vacuum cleaner or clean, dry pressurized air to suck or blow the dust and other debris out of the gap. If you hold the speaker upside down with the cone facing downward it will probably help getting the dust and debris out. Next, take a 3×5 index card and cut it into a strip that is the correct length so that you can form it into a circle and stick it down into the gap between the inside of the voice coil and the outside of the pole. This will help form the voice coil back into a circle. Next, lay the speaker back down on its back. Take a Q-tip or small paint brush and dip it into a bottle of acetone (finger nail polish remover). Spread a small amount of this acetone on a couple of the rings of the spider, which is the brownish/yellow corrugated disk attached to the backside of the cone at the base of the basket. Next, place a jar lid or other disk on the cone where the dustcap was and let the speaker set overnight. The lid or disk will prevent dust from getting into the gap overnight, and the acetone causes the spider to relax and reposition slightly, thus repositioning the voice coil. The next day, remove the lid and the index card strip and see if you still have a rub. If you do, try the acetone again, same procedure. If, after a couple of tries, it seems hopeless, then professional reconing is the only solution."