Serious speaker buzz - help needed

[zwiefldraader]

Hi,
don´t know if this is the right place for putting down my inquiry for help. Hope it´s alright.

I have a gorgeous sounding bluesbreaker style 212 cab. On of the speakers inside has some serious buzz. The other one as well a bit, but not that bad.
The buzz is around certain frequencies and is consistent with different amps. Also tried the speakers in several cabs - so it definitely the speakers.
The buzz is more annoying when turning the guitars tone pot / treble frequencies down, but always audible.
At lower volumes it seems to sound a bit like sand trickling on metal or stone. The higher the volume the buzzier it sounds and the more it is getting obvious.

I don´t want to change speakers if I don´t really have to, because these are old Pulsonic Celestions G12M25 Greenbacks with the 55Hz Cones. These are extremely hard to find - I only found three here in Germany during the last four or five years. And all of these came out of the same 4x12.

Any ideas. I have an extremely good speaker tech who can change the voice coil and re-use the original cone. But I´d love get an idea what it could possibly be.

best regards
s´Zwieberl

 

[Braciola]

Hate to be the bearer of bad news, but it sounds like one (or both) of your speakers need repair.
First thing I would do, is un-hook one at a time to see if one or both are giving you the buzz.
Then you need to find a reputable place to have them repaired.

I wouldn't trust my older Celestions with anyone but Chris Merren @ Merren Audio.
He's kind of hard to get a hold of, and doesn't usually answer emails.
You'll have to call till you get him on the phone.
He's well known for his awesome replica Transformers, but will also repair speakers.

 

[zwiefldraader]

Thanks @Braciola
I´ve read a lot good things about Merren Audio before, as well. My problem is, heading west, the Atlantic Ocean is between Merren Audio and me, at the east the Pacific Ocean has to be crossed (even longer). So I guess I will have to rely on the good engineering here in germany.
I would probably send the speaker to the trusted PPA Audio, a top-notch one-man operation.

Maybe I will have to tell a little more. In the first place I bought a G12M25 55Hz from a private seller. It was sold cheap for being completely broken. Though the Cone looked still very good, the voice coil was killed.
I sent it to PPA Audio and he refurbished the whole speaker, put a new voice coil in and glued the original cone back into the old chassis. So this speaker certainly was shot and repaired, but still / again has the original cone and chassis.
I put it into my 18w TMB and coudn´t be happier... aside there are still buzz-prone frequencies, but not because of a damaged voice coil, probably more or less what is called cone-cry.

Months after that I fond another pair of Greenbacks with the Bass-Cone. At the moment I still can give them back to the seller, though I don´t want to. I LOVE the overall tone.
Recently I found out, originally these came out of the same 4x12 cab as mine did.
So what I know is, the cab had been overpowered at least once (because my first speaker of the lot had a dead voice coil).

The buzzing frequencies are the same as in my repaired speaker. Btw. I can state that soundwise the original voice coil and the new nomex one are almost indistinguishable.

My question is, if the cone can have suffered from the overpowering. Is it possible, that certain frequencies are like "burned into the cone" causing buzz.
Any ideas?

best regards
s´Zwieberl

 

[zwiefldraader]

Anybody?

 

[irocdave12]

I was going to mention cone cry too. Interested to hear what develops

 

[rabidhamster]

Sometimes speakers are old and saggy and worn out even when they used to be great