Replacing the speaker in an old-is GK MB150S

I would shoot GK an email.

 

There’s also a speaker gasket that is absolutely essential. More than one of those amps has been sold dirt cheap because the gasket had rotted and the amp developed rattles that couldn’t be identified. For the $15-20 it probably costs these days I’d replace that too. That amp is still in production isn’t it? Contact GK.

 

It’s been over 10 years since I contacted them for MB150 parts but they responded pretty fast as I recall and hooked me up with what I needed.

 

Here's an image I found that shows that magnet assembly with what appears to be an extra plate with a screw hole in the middle.

Image from this ad Gallien-Krueger Bass Replacement Speaker 082-0039-O

 

gallien-krueger.com

 

Yeah contact GK. And the speaker gasket is a ring that goes between the wood of the speaker baffle and the speaker itself. It should line up with all of the screw holes that hold the speaker in place. It should look something like the pic below. (Not the one you need. Just an example from a Google search of speaker gasket.)

 

Is that normal folks? I'm trying to envisage it and I think failing, but it sounds like nothing I've ever seen.

 

MB150/112, 112MBX - Paragon 12", 100W, 8 Ohm, 37Hz, Bass Driver - gallien-krueger.com

 

I admit that it doesn’t sound like anything I have seen either. Perhaps the OP is describing it poorly.

 

GK sells all of their speakers on their website.

 

A photo of this post and foot arrangement might help. As I say I don't understand your description at all, but I wonder if it might be something non-standard a previous owner has put in might be better removed. Unless of course you've had it from new...

 

That is just a normal speaker, no extra plates or screws or anything. What are you referring to that's 'extra'?

 

This is the area I interpreted as possibly an added plate. Appears elevated, like its glued on after the fact.

Just trying to figure out what the OP is describing as missing. I.E. if the speaker does not look like this, perhaps he didn't get what he ordered.




Here's an image of the rear of the amp. Note, the screw in the middle of the back panel. It's not clear to me whether this screws directly into the center of the speaker or some other "post" that is between the rear panel and speaker. On my EV SX300 cabs, the horn drive is screwed directly to the rear panel, but this would seem unnecessary with a 12".

 

What size speaker it is ?

 

That part of the speaker is called the 'back plate'. Quite essential to the construction of the speaker, as it holds the magnet assembly together. So definitely not added on, every ceramic magnet speaker has that.

 

I think you're probably correct. I thought possibly that was a mounting adapter glued to the back plate.