Speaker problem, how to fix?

V

Vigilante

Gear nut
Hi, I've got a pair of floor speakers, they are older and it has the name "Reference KLH" on the front. From what I can tell, it looks to have a 4", a 6", and maybe a 15" or 16" speaker in the cabinet. That is, it has three speakers in there, or drivers, I guess they're called. It's covered by a black screen so I can't tell.

Anyhoo, one the speakers is going bad and I don't know what it means. Basically it randomly switches between 3 things: 1, it will just plain turn off, suddenly goes silent, and may not come on again for a bit, or if I fiddle with the volume from my amp. 2, it will actually sound normal, but doesn't stay there long. And 3, it puts out this nasty static sound. It's not constant, like a hiss or white noise, it sounds like if you were to stick a mic outside in the wind and turn up the gain. Just popping, hissing, blowing in a random type pattern.
The volume of the static does not correspond to the volume from my amp. In fact if I turn the amp to nothing, it is still hissing and screeching at the same volume. I have to completely unplug it from any source to get it to shut up. They are not powered speakers.

I tried to record the sound it makes only I just get feedback when I try, so I have to explain it the best I can. It really sounds like wind, only it isn't a constant volume or anything. It's static, basically. Random white noise popping.

I hope that makes sense, but I don't know what to do. It sounds like the big 15" driver is doing it, not the little ones. So is the speaker bad? Is there just a loose connection in there? Something need resoldering? Is there anything in particular I can check or is there some way to test it?

If you don't have the answer, is there another forum or some place I can research how to test and repair speakers, any help at all would be great. I'm kinda techy and don't mind getting in there and messing around.

Thanks!
 
OK, I took the big driver and medium driver out. It seems the two smaller drivers have a capacitor on the circuit. Also it sounds like I'm getting static from both the big and middle drivers. Not just the big one.

The smaller driver has a capacitor (I think it's a capacitor) which says "Verit 100v 4.7uF" with a wire sticking out both ends, the wire is bare, has no heat shrink tubing or anything on it. The smallest driver has the same thing only it says 2.7uF. The smallest one is not static though.

I guess I could blame the capacitor, but then, the large driver doesn't use one, so why is IT noisey? The drivers are not daisey chained, they all go back to the area of the back connector. So each driver connects to the back, and the two small drivers have a capacitor on one of the wires.

Don't know if that helps. Wiggling the wires doesn't seem to do anything, maybe a little but not consistent, the connections feel strong and are crimped well.

What next?
 
I assume you've swapped the speakers to make sure that it isn't a problem with the amplifier.

Beyond that, if it were only a single driver, this kind of sounds like a failing voice coil in the driver, which would mean replacing the driver.

However since you are seeing it in both the woofer and midrange, I really wonder if it isn't something wrong with the amp or a bad cable or something else. Either that or maybe there's a bad solder joint somewhere. You might also try spraying the connections with DeOxit or other equivalent contact cleaner.
 
Not to seem like a smartass, but speakers dont make noise by themselves.
He says that sometimes it make the noise even with the volume all the way down, this is going to be an amp problem not a speaker problem.
The caps on the speakers that you mention are basically just filters.
They filter out certain frequencies to the speakers.
Take a good look look at your speaker to amp connections.
Also swap the speaker positions, I mean exchange left and right.
see if the problem follows the speakers, or stays the same.
 
Basic troubleshooting..........

Since its only happening with one speaker and you have an identical pair to work with it should be easy to troubleshoot....

1) First swap the left speaker with the right to determine if the problem is with the speaker or just one side of the amp.

2) If the problem persists on the same side, next swap your cables to make sure one of them isnt the problem.

...A) If its still happening on the same side then the problem is one of your amp channels.

...B) If the problem follows to the other side then its was your cable

3) If the the problem instead follows the speaker I would then swap drivers between cabinets to determine if any are bad.

...A) If the problem follows a specific driver, then you know its that driver.

...B) If the problem instead continues in the same cabinet then the problem is probably an internal wiring, connector, capacitor, or input jack issue. (To determine which you'll then want to start swapping out internal components one by one with the other cabinet until you hit the nail on the head).

Best of luck
 
Last edited:
Hey this is like bringing a thread out of the grave, but I want to bring closure. It did end up being the amp after all. Or at least, the 2nd channel of the amp. The reason it was hard to troubleshoot is that it randomly changed it's behavior. Turn the amp off and on or swap cables and it would work in a different way. So yes, on the 2nd channel, it either works great, doesn't work at all, or makes the static noise in random patterns. I had to leave it all connected in different patterns for a length of time to fully realize what it was doing.

A guy at a local audio store said they have another guy which can fix the channel with no problems. I told him the behavior was sporatic and asked if I should wait for it to fully die, and he said it can be fixed before it dies. I hope so, I don't want to get it back and have him said everything worked great. Cause of course, it DOES work great sometimes, not all the time. I wonder if he can find the problem, or maybe somebody can tell me what it might be and if I could test it or replace something myself? Is it just the volume control? One of the capacitors or resistors?


Thanks for helping!
 
most likely you've got a cleaning or bad solder joint problem... transistors for instance dont kinda break for awhile... they work or their blown... intermittent problems are almost always connection issues...
 
Vigilante said:
Hey this is like bringing a thread out of the grave, but I want to bring closure. It did end up being the amp after all. Or at least, the 2nd channel of the amp. The reason it was hard to troubleshoot is that it randomly changed it's behavior. Turn the amp off and on or swap cables and it would work in a different way. So yes, on the 2nd channel, it either works great, doesn't work at all, or makes the static noise in random patterns. I had to leave it all connected in different patterns for a length of time to fully realize what it was doing.

A guy at a local audio store said they have another guy which can fix the channel with no problems. I told him the behavior was sporatic and asked if I should wait for it to fully die, and he said it can be fixed before it dies. I hope so, I don't want to get it back and have him said everything worked great. Cause of course, it DOES work great sometimes, not all the time. I wonder if he can find the problem, or maybe somebody can tell me what it might be and if I could test it or replace something myself? Is it just the volume control? One of the capacitors or resistors?


Thanks for helping!
Click to expand...


just clean your volume control and see if it clears up, the static would most likely be dirt, secondly in the signal path it would be the most likely offender that would cause described behavior. Look to the simple solutions first the rest of
what you mentioned seems totally unlikely. the best way to confirm this is when the symptom occurs move the volume control on that channel and work it back and forth and see if it causes an improvement in the performance of the amp.
 
It is most likely your volume knob or a bad ground. Bad grounding will often cause that wind type noise you described. I would buy some contact cleaner and use it on the volume control. Also you might just look around for any obvious loose solder connections and you might save yourself a trip to the repair shop. Check all the speaker connections on the inside of the amp and any of the RCA connections first. Also if it is a really old amp check the mode selection switches/buttons to see if there are any broken solder joints and use the contact cleaner on them also. Good luck.
 
You must log in or register to reply here.
Back
Top