Need Help with Cab Speakers

E

eph826

Jul 28, 2021
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#1
Hi there! I'm new here and new to cabs, as well. I bought a GK 810GLX and thought it would be an easy project. Well here I am.

I don't know the technical terms, but four speakers out of the 8 have a wire that seems to have burned off. Here are pictures:
20210728_200421.jpg 20210728_200346.jpg
So my questions are:

1. What caused this and
2. Is the fix to simply resolder the wire?

Thanks!
 
#2
My memory may be wrong, but I remember the wires from the terminal going to the voice coil being thinner an flexible. Get in there with a light and check. Those ones with black insulation look much too heavy…
 
#3
It's really hard to tell much from those photos, but it's clear the leads to the voice coil are no longer connected. To a certain extent, it IS just a matter of resoldering the connections, but those failed for a reason that I can't discern from the pics. I'm kinda with @wave rider - those tensile leads should be very thin and flexible, and I haven't looked at too many modern drivers (except for those from just one manufacturer), but I can't say I've ever seen a case of those thin tensile leads being insulated. Those leads have to be very strong and flexible, since they get flexed thousands of times per second ad infinitum, hence the requirement that these be that highly specialized, high-tensile-strength wire. It's not clear to me that's what's there with the drivers in the pics. I presume you did not buy this cab new? And what do you mean by "...and thought it would be an easy project." -- did the cab need some other repairs?

Edit: After looking at the magnified pics more closely, it looks kind of like the failed wires actually are the proper type, or at least could be, especially in the first of the two pics. I guess it couldn't hurt to resolder them and see how long they last. The problem is the solder that wicks up the wire during the soldering process makes the leads themselves stiff and they will tend to break at the point where the solder stops -- at the transition from stiff to flexible. This is the reason for that elaborate soldering arrangement where the leads are drawn through the terminals and soldered on the opposite side -- this is to help prevent that solder wicking from extending up to the part of the wire that must remain flexible. This may have been the problem that led to the failure of these leads in the first place. Do you know of a speaker repair shop... where you can get a speaker reconed? They might be able to effect a more durable repair than you can. Maybe.
 
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#4
Not much to add, but the reason why those leads are insulated is probably because the cones are metal. If both wires were to touch the cone the would short out, which is not an issue with a normal paper cone speaker.

And yes it's just a matter of resoldering them. But now the problem is that they will be too short, and you can't have them pulled tight. Also, something made them break so that may be an issue as well.
 
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#5
Thanks for all the feedback, guys.
So I bought this cab at Goodwill for $40 and a Google search for "GK 810GLX" sounded worth it. When I got it home to test it, I found 4 of the 8 speakers didn't work and found this when I opened it up. It's definitely OEM - just old. Probably why it ended up at Goodwill.

What I'm gathering is, because it's older and uses an older style of wiring (insulated, thicker), repairing it may not be feasible. The remaining cable is too short and due to the constant vibrations, the solder would not hold very long.

SO - should I just cut my losses? Or is this cab worth fixing? If worth fixing, I presume that would involve reconing the 4 speakers.

Lastly, what would have caused this and can I be sure it won't happen again? My uneducated guess is it happened from someone using the wrong head. ‍♂️

Some more pictures just because
20210728_221854.jpg 20210728_221907.jpg 20210728_200522.jpg 20210728_200834.jpg20210728_200617.jpg
 
#6
mmbongo said:
Not much to add, but the reason why those leads are insulated is probably because the cones are metal. If both wires were to touch the cone the would short out, which is not an issue with a normal paper cone speaker.

And yes it's just a matter of resoldering them. But now the problem is that they will be too short, and you can't have them pulled tight. Also, something made them break so that may be an issue as well.
Click to expand...

Good call. I remember seeing but didn't remember the details of GKs with metal cones. D'uh!
 
#7
eph826 said:
Thanks for all the feedback, guys.
So I bought this cab at Goodwill for $40 and a Google search for "GK 810GLX" sounded worth it. When I got it home to test it, I found 4 of the 8 speakers didn't work and found this when I opened it up. It's definitely OEM - just old. Probably why it ended up at Goodwill.

What I'm gathering is, because it's older and uses an older style of wiring (insulated, thicker), repairing it may not be feasible. The remaining cable is too short and due to the constant vibrations, the solder would not hold very long.

SO - should I just cut my losses? Or is this cab worth fixing? If worth fixing, I presume that would involve reconing the 4 speakers.

Lastly, what would have caused this and can I be sure it won't happen again? My uneducated guess is it happened from someone using the wrong head. ‍♂️

Some more pictures just because
View attachment 4349863 View attachment 4349864 View attachment 4349861 View attachment 4349860View attachment 4349865
Click to expand...

I think that somebody that knows what they are doing could fix them easily. The wire itself is fine, they have been using that wire for speakers for 900 years. Yours are just thicker/insulated to keep them from touching the cone.
 
#8
Presuming it is the right wire -- which it appears to be -- the problem of the shortened length would still need to be addressed. You'll notice that the original wiring had about a half-inch of excess on the soldered side, and again, this is to try to help alleviate the solder-wicking issue.

A simple re-soldering might get them to work again for a while, but wouldn't be a reliable repair, IMO. A less-than-scrupulous person might effect that repair and put the fully working cab on Craigslist at an appealing price. (Of course, I'm sure no TB-er would do that sort of thing. :D)
 
#9
The insulation on the wire is actually a silicone type damping sleeve to limit the resonance of the wire (and fatigue failure).

More often than not, this type of failure cones from beating the drivers to within an inch of their lives over time.

A pro recone shop might be able to replace the tinsel wire, but usually it’s not a practical repair long term. It’s also not an easy repair since the dust cap needs to be removed and replaced too. If the junction with the VC lead out wire is embedded in epoxy or MEK adhesive, it’s pretty much impossible.
 
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#10
The GK goldtone speakers are notorious for blowing easily and that’s what’s happened here. Somebody hit em with way too much power. Given that you’re only in for $40, I’d bail on this project.

However.

If you really want this fixed, I’d simply keep scanning the GC online used section. GLX cabs show up all the time. Last I looked 410s were running around $199. Of course, those might be blown too, it’s not like GC checks their used gear with any kind of care. But you could, in theory, have an 810 GLX cab for around $300-$400. Me, I wouldn’t do it.

edit: fixing this or buying drivers is doubly risky because the survivors got hit with the same abuse. There’s probably at least one or two in there that are one set away from going to the great speaker box in the sky no matter how careful you are.
 
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#11
For 40$, I'd probably try to solder the wire back again, if only to learn a thing or two about speakers. And if the speakers get beyond repair, I'd convert the 810 into 410, if only to learn a thing or two about boxes. You might even end up with a perfectly working cab!
 
#17
^^^ I'd try what @jimkelly said, first.



Failing that, I'd cut the cabinet in half and make it into a 4x10.

It's rated at 4 ohms with all 8 speakers running. The speakers are the GK Paragon 10s, which are 32 ohms each.

With only 4 speakers connected, the cab will be rated at 8 ohms. Also the power handling will be cut in half.
 
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#18
Lots of information here - I really appreciate it. I'm probably going to cut my losses and try it out as a 4x10 cab, considering I'm not the best at soldering. Thanks again, everyone!
 
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#19
Are there separate air spaces for each group of 4 drivers? If so, you should be ok.

If all of the drivers share a common air space, that not going to work very well and the drivers need to be derated due to the incorrect acoustic loading. Probably by ~50% at least.
 
#20
Redbrangus said:
Presuming it is the right wire -- which it appears to be -- the problem of the shortened length would still need to be addressed. You'll notice that the original wiring had about a half-inch of excess on the soldered side, and again, this is to try to help alleviate the solder-wicking issue.

A simple re-soldering might get them to work again for a while, but wouldn't be a reliable repair, IMO. A less-than-scrupulous person might effect that repair and put the fully working cab on Craigslist at an appealing price. (Of course, I'm sure no TB-er would do that sort of thing. :D)
Click to expand...
You can stop the solder wicking up the tinsel leads by holding them with needle-nose pliers just under the terminal when soldering. Chances though, they are they are too short now to resolder.
 
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