Blown speaker?

[cap217]

I bought an amp off someone on here. It arrived and works fine except for a buzzing sound on the bass notes. This happens at lower levels so its not a volume thing. I spent a lot of time this weekend tightening and testing and trying to stop this buzz. I took it to an amp tech for a quick look and he said one of the speaker were bad. He didnt have time to look into it so I left.

Today I tried to isolate everything I could. I finally just took each speaker out and hooked each up to my deluxe reverb. The buzz was still there so I know its the speakers 100%. What surprised me is that BOTH buzz. The have full range of frequency, they sound good besides the buzz, the ohm readings are correct.

When I push down slightly on the outside of the speaker while its vibrating, the buzz stops. There are no rips or tears on the speakers. They seem good to me.

How can both be doing this? I tried different cables and another speaker the same way, no buzz...




http://youtu.be/VTQlrBOqQk8

[Cantplay]

Could it be the tinsel leads buzzing?

John

[JazzGuitarGimp]

Disconnect the speaker and lay it on its back, cone facing up. Place both thumps and index fingers at four points on the cone, equally spaced and halfway between the dust cap and the surround. Press gently and evenly several times, in a pumping motion. There should be no sound from the speaker. If you hear any signs of rubbing, the voice coil has been stressed and the speaker needs to be reconed.

[xtian]

Disconnect the speaker and lay it on its back, cone facing up. Place both thumps and index fingers at four points on the cone, equally spaced and halfway between the dust cap and the surround. Press gently and evenly several times, in a pumping motion. There should be no sound from the speaker. If you hear any signs of rubbing, the voice coil has been stressed and the speaker needs to be reconed.

Exactly. I've had no trouble doing this with mounted speakers, as well. Though you do have to be careful not to mistake the sound of your fingers sliding across the cone as coil rub.

[cap217]

I push down but no noise.

[JazzGuitarGimp]

I push down but no noise.

Then there must be some mechanical issue with the speakers: aloose bell cover or perhaps a loose termination strip. Are the voice coil wires that run from the termination strip to the back of the cone touching the frame?

And, you're sure the buzz is coming from the speaker itself and not something in the room, vibrating in sympathy?

[cap217]

I push down but no noise.

Then there must be some mechanical issue with the speakers: aloose bell cover or perhaps a loose termination strip. Are the voice coil wires that run from the termination strip to the back of the cone touching the frame?

And, you're sure the buzz is coming from the speaker itself and not something in the room, vibrating in sympathy?

The terminals are fine. I thought it was those at first but its not. I am 100% positive it is the speaker that buzzes. It buzzed in the amp and it buzzes out of the amp. I also put a speaker exactly where these speakers were to test and no buzz.

When I push down slightly on the outside surrounding of the speaker while its buzzing, it stops.

I am at a total loss here. I cant figure this out!

[Structo]

Have you spoken to the guy you bought the amp from?

BTW, what kind of speakers are they?

What you describe sound like voice coil rub, but you should be able to feel that when you manually press down on the cone evenly.

[Firestorm]

If it's a relatively minor voice coil rub, it may be fixable without a recone. You'll have to Google it 'cause I can't remember how.

[cap217]

Seller said that the speakers worked when it shipped. I am stuck with these.

Speakers are celestion vintage 10s.

[Structo]

Has the seller tried to help you with this problem?

[Bob-I]

Seller said that the speakers worked when it shipped. I am stuck with these.

Speakers are celestion vintage 10s.

I'm convinced speakers can be damaged by rough handling in shipping. I've shipped equipment to out of town gigs a few times. I had a perfectly good JBL D120 show up at the other side with a buzz. I sealed the box myself, and opened it myself at the other end.

A sound man I worked with years ago swore by shorting the speaker terminals before shipping. He claimed that the voltage produced by the cone moving created a magnetic field that slowed down cone movement during shipping. True or false, I don't know but he had a bunch of shorting plugs he put on his cabs before putting them in the truck.

[Diablo1]

Seller said that the speakers worked when it shipped. I am stuck with these.

Speakers are celestion vintage 10s.

I'm convinced speakers can be damaged by rough handling in shipping. I've shipped equipment to out of town gigs a few times. I had a perfectly good JBL D120 show up at the other side with a buzz. I sealed the box myself, and opened it myself at the other end.

A sound man I worked with years ago swore by shorting the speaker terminals before shipping. He claimed that the voltage produced by the cone moving created a magnetic field that slowed down cone movement during shipping. True or false, I don't know but he had a bunch of shorting plugs he put on his cabs before putting them in the truck.

Well, he was right about the shorting jack limiting the VC movement, but I don't know if that prevents speaker damage during shipment. You can also get a VC rub if the glue that holds the spider fails from age, or if the spider itself gets weak. I had that happen on some 40 year old speakers that had limited use and never were shipped anywhere.