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Re: G12m-25 making strange buzz

Posted: Sun Feb 02, 2014 3:09 pm
by Scumback Speakers
Once the cone & coil are history, it's a $15 - 20 frame by itself.

Re: G12m-25 making strange buzz

Posted: Sun Feb 02, 2014 3:29 pm
by vmazz
Bummer. Not really worth shipping anywhere either ..unless I send it to get reconed huh. Jim where would I get a decent recone kit for this?

Re: G12m-25 making strange buzz

Posted: Sun Feb 02, 2014 5:52 pm
by Scumback Speakers
vmazz wrote:Bummer. Not really worth shipping anywhere either ..unless I send it to get reconed huh. Jim where would I get a decent recone kit for this?
:palm:

:lol:

http://www.scumbackspeakers.com/recones.html" onclick="window.open(this.href);return false;

You can't get an original Pulsonic cone. I do recone these, this one would be the M75-PVC recone kit, 16 ohms.

Look, if you don't want it, I'll pay you $35 for it including shipping. I've got other old frames like this I can match it up to (also rebuilt to M75-PVC specs). Some day I'll probably have a quad of them.

Re: G12m-25 making strange buzz

Posted: Sun Feb 02, 2014 6:12 pm
by vmazz
:lol: uh ...oh yea..sorry Jim. Of course you can do the reconing, which im considering.
Im also thinking of trying to get a kit and recone it myself, I know that i might mess up the kit, but ill learn about reconing. Anyways thats a long shot ,but if I wanted to get a good kit to do it myself, where could I find one? I see some g12m kits around but they dont give specifics about the cone etc
Thanks

Re: G12m-25 making strange buzz

Posted: Sun Feb 02, 2014 6:29 pm
by Scumback Speakers
AFAIK,there are only Celestion kits. I don't have kits I sell. I've got hundreds of cones/coils, etc, but I don't offer my kits for sale, only as recones.

There's more to it than the kit. There are four different glues in a speaker, shims of various thicknesses dependent on the particular frame and gap needed (yes, Celestion doesn't standardize folks), and then you have to know how to set the right coil height, and dope the speaker.

I'm training a new guy to work with us. He's got it down pretty well after building 40 speakers with two of us looking over his shoulder to stop him from making a mistake or getting stuck.

But reconing a speaker is much more labor/effort/knowledge than building a new one. By the time you buy all of the glues, shims, etc it would be cheaper to have it rebuilt for you.

But you can probably buy a kit from an authorized Celestion warranty depot or rebuilder. Not sure where there's one in Nor Cal, but do a google search, or check Celestion's site. Good luck!

Re: G12m-25 making strange buzz

Posted: Mon Feb 10, 2014 1:41 pm
by rgorke
Scumback Speakers wrote:Val, I just had one like this come into the shop (different cone, 1777) from another client. His voice coil wires had come loose, either from the shellac degrading, or the voice coils was overheated and the wire unraveled.

It had the exact same symptoms yours has, except there wasn't even mouse fart output due to the coil wire shorting out.

It had to be reconed to fix it. Your speaker sounds like it's doing the same thing.
So what does this sound like? Over the weekend I had an opportunity, with no one home, to play my amp loud. And "loud" is with my Plexi clone at 80 volts going through the attenuator full open (as opposed to bypassed) which still takes off 6 db.

So, not all the time but on some hard hit chords, I get the bffvvvttt sound almost like a slap echo. Is that what this is? Granted I only rarely play at this volume and it doesn't happen at lower volumes.

Does anyone have a recording of the type of problem that Val is describing so that I can compare with my bffvvvttt?

Thanks

Re: G12m-25 making strange buzz

Posted: Mon Feb 10, 2014 10:33 pm
by vmazz
Hear are samples with the buzzing and before the buzzing started. It sounds like a sizzle on this sample.

heres the buzz

https://soundcloud.com/vmazzone1969/greenback-buzzing" onclick="window.open(this.href);return false;

here is without

https://soundcloud.com/vmazzone1969/gre ... le-no-buzz" onclick="window.open(this.href);return false;

Re: G12m-25 making strange buzz

Posted: Tue Feb 11, 2014 2:19 pm
by rgorke
Thanks, that IS different than my Bvvvffffttt sound mine makes. Mine is short after the chord or note but mainly chord is struck.

So, did you get it fixed or is that an old recording?

Re: G12m-25 making strange buzz

Posted: Tue Feb 11, 2014 6:51 pm
by vmazz
Old recording, I just happened to be making some samples of that speaker a few weeks before it started to make the buzz/rattle/fizzle sound. :palm:

Re: G12m-25 making strange buzz

Posted: Tue Feb 11, 2014 9:45 pm
by Scumback Speakers
rgorke wrote:Thanks, that IS different than my Bvvvffffttt sound mine makes. Mine is short after the chord or note but mainly chord is struck.

So, did you get it fixed or is that an old recording?
Roger, your speaker sounds like it's one of the following.

Loose spider, or coming unglued causing a flapping noise.

Loose dust cap, also flapping.

Or it's got a coil that's slowing going out of round or slightly burnt/bubbled.

Sorry.

Jim

Re: G12m-25 making strange buzz

Posted: Wed Feb 12, 2014 1:36 pm
by rgorke
Scumback Speakers wrote:
rgorke wrote:Thanks, that IS different than my Bvvvffffttt sound mine makes. Mine is short after the chord or note but mainly chord is struck.

So, did you get it fixed or is that an old recording?
Roger, your speaker sounds like it's one of the following.

Loose spider, or coming unglued causing a flapping noise.

Loose dust cap, also flapping.

Or it's got a coil that's slowing going out of round or slightly burnt/bubbled.

Sorry.

Jim
Ugh. :palm: Well tomorrow's gonna be a snow day, maybe I'll open up the cabinet and check.

Re: G12m-25 making strange buzz

Posted: Wed Feb 19, 2014 12:10 pm
by rgorke
So, I opened up the back of the cabinet and for the life of me couldn't make it do the noise. I noticed that I seem to have long wires hooking up the speakers to removed the back and not be worried about pulling something. I wonder if one of the wire was bouncing on one of the cones? I am at a loss.

Re: G12m-25 making strange buzz

Posted: Wed Feb 19, 2014 1:19 pm
by Scumback Speakers
I had a client do that once, so it's possible. Easy way to do this...use the least amount of wire between the speakers possible, but tape your input jack to speaker wire around your sound post with duct tape. That way it won't move around when you put the back panel on.

See if that takes care of it. Here's a wiring diagram for the least amount of wire in a 4x12...parallel/series wiring.

Image

Re: G12m-25 making strange buzz

Posted: Wed Feb 19, 2014 5:46 pm
by rgorke
Thanks Jim, I ended up using a tie wrap to keep them secure. Remember this long thread. Brings back good memories of Mark.

http://forum.metroamp.com/viewtopic.php?f=14&t=17542" onclick="window.open(this.href);return false;