Got the speaker buzz

[genmin]

Turned on an amp that has been sitting for awhile, have a buzz coming from one speaker. Never had it before, not to say because it has been sitting that this is why the buzz showed up.Disconnected one of the two speakers and it is apparent that the one has a buzz. No tears in paper or the ribbed paper at the voice coil, no loose wires. Some other party suggested it could have a had a voice coil drop. Can a voice coil being dropped be fixed. Does reconning a speaker not always have to do with a broken cone or ripped up paper. It is a Jensen C12N from a Fender Twin Reverb. Any other ideas as to my problem or an answer to my fix. Maybe someone explain what a voice coil drop is????Thanks

[Glowbug]

Sounds like what he's describing is a misaligned voice coil, due to sagging of the soft parts...the spider loosening up over time. Try connecting a small battery to test the coil, as described here:

Voice coil rub: Diagnosis and repair. [Archive] - AudioKarma.org Home Audio Stereo Discussion Forums

If that confirms it, you could try finding a recone kit, which would consist of replacing the soft parts (VC/former, spider, cone, surround).

[chris661]

Sounds more like interferance to me.

Does the buzz occur when you switch it on, or when you put something through it?

[genmin]

No it is not interference, as far as lighting circuits, house wiring or flourescent light transformers. I have it in a Fender Twin Reverb cabinet with another alike speaker,the two together are okay but the one has an issue, I disconnect the good sounding one and the other has what I would call a rattling when either playing a bass string or even higher notes. Not really a buzz, some people call this farting out or flabbing and maybe this is not even what it is, it is audible but sounds like an effect box is being used, just trying to find the cure. I want to know what I really have before I send it off for a recone. At this point until I get enough responses I cannot make the call as far as it needing a recone. As said, no broken parts are visable. I guess if a professional had the item in hand, a better diagnoses could be given, I just thought I would get some input from users and knowledgeable folks like you all. Would like to hear some more

[mjf]

hello.
.......a hidden tear in the paper?
or some dirt/parts between the papercone and the chassis metal?
.....loosely screw or so.
......voice coil scratches? press with your finger a little bit into the center of the cone and listen if you hear some scratching noise (amp off).
greetings

[chris661]

Oh, I see now.

I had this problem with a 15" paperweight. The driver had been dropped, and the polepiece in the centre of the voicecoil had gone to one side, trapping the voicecoil. Those things are really hard to shift - hit it too soft, it doesn't go anywhere, too hard and it just goes to the other side with a clank.

I'd say replace the speaker, or get a professional to have a look at it.