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Replacing the speaker in an old-is GK MB150S

My MB150S started farting when I play a low F. I opened it up and found that the speaker is supported on a post which is screwed to the back of the cabinet, on top of which is a rubber foot attached to the post with a screw, which had worked loose. I tightened it up and put it all back together and it seemed to work fine for a couple of months. Then it failed again, and this time I found that some kind of rubber attachment to the back of the speaker had degraded. I ordered a new speaker from Thomas.de but found that it didn't have the rubber parts. Does anyone know where I can get the rubber parts?
 
My MB150S started farting when I play a low F. I opened it up and found that the speaker is supported on a post which is screwed to the back of the cabinet, on top of which is a rubber foot attached to the post with a screw, which had worked loose. I tightened it up and put it all back together and it seemed to work fine for a couple of months. Then it failed again, and this time I found that some kind of rubber attachment to the back of the speaker had degraded. I ordered a new speaker from Thomas.de but found that it didn't have the rubber parts. Does anyone know where I can get the rubber parts?

I would shoot GK an email.
 
Yes, that's what I got. But I need the grommet thing to go on the back of it.

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.)
images.jpeg.jpg
 
My MB150S started farting when I play a low F. I opened it up and found that the speaker is supported on a post which is screwed to the back of the cabinet, on top of which is a rubber foot attached to the post with a screw, which had worked loose. I tightened it up and put it all back together and it seemed to work fine for a couple of months. Then it failed again, and this time I found that some kind of rubber attachment to the back of the speaker had degraded. I ordered a new speaker from Thomas.de but found that it didn't have the rubber parts. Does anyone know where I can get the rubber parts?
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.


upload_2019-4-30_12-16-49.png


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".

Link Removed
 
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.


View attachment 3402099

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.


img_3009-jpg.1059903
 
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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.


img_3009-jpg.1059903

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

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