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Trouble with my GK Neo 112 II cab

socialleper

socialleper

Bringer of doom and top shelf beer
May 31, 2009
10,158
13,692
Canyon Country, CA
#1
I've had a pair of the GK Neo 112 II cabs for about a year now, and so far they've been awesome. However today one started acting up and I don't know if I'm in deep trouble or if there is a known fix.
I've got two of them, so I was able to make sure it wasn't the cables, the bass, or the outputs from the head. What's happening is I don't get any sound from it unless I pound a low note really hard, and then the note is very distorted and full of static. Once I have it making noise, it will still sound distorted when played more quietly until it stops making any noise again.

Does anyone know what this might be, or experienced something similar with these cabs? I know the predictable "Take it in" answer will be forthcoming; I don't have a repair shop near by and I don't want to pay a diagnostic fee just to have someone say it's totally #%$@ed, or if it's something common with an easy fix.
 
#3
check input with a multimeter. If it is large impedance or a short check each wire continuity separately all the way to the speaker. Then check at speaker as well. If it is not the wiring and the speaker connection is good then you have a blown speaker.
 
#5
set multimeter for ohms then put across + and - terminals. If a nominal reading OK if a short or a large reading not OK; if a short make sure it is not in your wiring before you say it is in the speaker. If large reading make sure y terminals are fastened good by starting at the input jack with + to the + at the speaker; it should have no resistance - then same for - terminal.
 
#9
vmabus said:
I'm gonna guess toasted voice coil; from the front of the cone, gently and evenly push the cone in with four fingers evenly spaced. It should move freely with no scuffing. I think it won't...
Click to expand...

I'm leaning a little this way too. I need to hit it with a volt meter to test the resistance. When I push on it gently it seems to move OK. I've never really tested that sort of thing on my own before so it might be hard for me to judge.
 
#11
vmabus said:
I'm gonna guess toasted voice coil; from the front of the cone, gently and evenly push the cone in with four fingers evenly spaced. It should move freely with no scuffing. I think it won't...
Click to expand...

I got a nice healthy 6 ohms on the speaker when I tested it with a volt meter.
Do the speakon connectors ever go bad? My Shuttle head only has these so I can't check the 1/4 input on the cab.
 
#12
Sounds like your driver is fine and your problem may be in a less than perfect connection somewhere in the signal chain. If you are handy (yet diligent and careful) with a screwdriver, swap the drivers between the two cabinets. You could also do the same thing with the cross-overs. If you are fiddle thumbs with a screw driver leave it to some one else you don't need a punctured speaker cone to add to your situation. The cross-overs in those cabinets use a circuit board, and if there is a cold solder joint somewhere that could be the cause.
 
#13
Speakon connectors do sometimes have problems, in the ones I own the individual conductors are secured down with a screw and that can come loose, I had 1 of them like that out of the box from GK.

I would call GK for advise, they have been very good at answering questions and helping, one of their techs, Jason is very knowledgeable and has always been willing to help.
 
#14
acmeseed said:
Speakon connectors do sometimes have problems, in the ones I own the individual conductors are secured down with a screw and that can come loose, I had 1 of them like that out of the box from GK.

I would call GK for advise, they have been very good at answering questions and helping, one of their techs, Jason is very knowledgeable and has always been willing to help.
Click to expand...


Good point. Make sure you swap speaker cables before you do anything else.
 
#16
Now it's getting weird:
I took apart the entire cab to check all the connections, which seemed tight. As I stated the ohms on the speaker its self were where they should be. I tested the internal speaker cables, which came out to .5 ohms, everything looked tight. The PCB of the cross over doesn't have any burn marks, and the two lamp fuses look OK, but I can't be sure. I looked in the speakon terminal to make sure there wasn't any debris in there, and tried to test it with my multi-meter but I'm not smart enough to figure out where I need to put the leads. After I put everything back together it started working just fine.
WHAT?!
On the plus side I got it working again at no cost.
On the negative side I have no idea what happened which means this could potentially happen again; maybe during a show!

The tweeter was working the whole time, BTW.
 
Last edited:
#18
After getting the cab to work I still noticed a light distortion in that cab, so I took a look at the crossover boards on both cabs. One is one a year old and I purchased it new. The one that is having problems is older and I bought used.

Newer:
tmp_15527-20140704_190536-1069026729_zpsf4c5a27e.jpg


tmp_15527-20140704_190523-1034079683_zpse211514b.jpg


Older w/ problems:

tmp_15527-20140704_1905011028859228_zps8a225011.jpg


tmp_15527-20140704_190444492400739_zpsaa8a4390.jpg


Now it pretty obvious that the back of the older cabs PCB has got some crust on it, and whatever that circular thing is on the front of it has some goop around it. The newer one is much cleaner.
Is there anything I can do to clean this thing up, or do I have to replace it? If I have to replace it, does anyone know what it might cost?
 

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