Can these speakers be repaired?

[Keshenatech1]

I was asked to look at some guitar amps by the owner of the local pawn shop. One is a Kustom model 11-L and the problem with it is "no sound". It has 2 12" speakers in parallel and I found the 1/4" jack coming from the speaker harness going into the amp measures wide open, no continuity whatsoever. At first I suspected a broken wire but the problem is on the speakers themselves. I don't know if someone vandalized it, or if it deteriorated, but both leads on both speakers coming from the cones to the terminals are severed. The leads are a very soft flexible material with cloth woven in. Before getting close to the cone with a soldering iron, I experimented with the end still on the terminal attempting to solder some stranded copper wire to it. Even with the use of extra flux and a good amount of heat from a wide chisel tip, the solder refused to bond to the lead and my copper wire fell right off. As you can see in the pictures, I only have just over 1/4" of material to work with in a couple spots. Does anyone know how to make a reliable connection to the ends of the leads or if it's even possible, or are these speakers junk?

[stj]

Re: Can these speakers be repaired?

professionals can re-cone them.
they completely replace the coil and paper parts.

i think you can buy the parts seperatly but you need to get the coil diameter just right.

[petehall347]

Re: Can these speakers be repaired?

cut the dust covers off and solder new tinsel leads to the coil wire .

[eccerr0r]

Re: Can these speakers be repaired?

I've repaired a 5¼" (IIRC) woofer with the same problem before, it is possible, though my situation probably belongs in the "worthless repair" thread...

Key thing is that you don't use any of the old tinsel wire, you have to get rid of all of the old tinsel wire up into the cone. Solder the new tinsel wire to the coil in the cone. and yes you need to get more tinsel wire.

Since it was a 5¼" driver i was cheap and did not find new tinsel wire for it. Made my own homemade voice coil wire, alas I doubt it will last forever, but neither did the original tinsel wire so no big deal...

[momaka]

Re: Can these speakers be repaired?

cut the dust covers off and solder new tinsel leads to the coil wire .

+1
This would probably be the easiest solution.

And if you don't care much about doing an ulta-proper repair, you can even forgo using new tinsel leads and just use regular stranded copper wire. Just pick one with finer strands inside so it's a little more flexible, and it will be fine. Make sure not to leave too much slack so that the wire flaps somewhere on the cone and makes ugly farting noises.

though my situation probably belongs in the "worthless repair" thread...

So does mine when I "repaired" these pieces of garbage. But hey, I was curious to see how bad they would sound... and they delivered.

I suppose many things are fixable, even if they seem like they aren't. At the end of the day, it's just down to how much time you want to spend/waste with something... and what kind of satisfaction you'd get out of it (if any.)

[kaboom]

Re: Can these speakers be repaired?

And if you don't care much about doing an ulta-proper repair, you can even forgo using new tinsel leads and just use regular stranded copper wire. Just pick one with finer strands inside so it's a little more flexible, and it will be fine. Make sure not to leave too much slack so that the wire flaps somewhere on the cone and makes ugly farting noises.

Or hits the basket and shorts the amp!

I suppose many things are fixable, even if they seem like they aren't.

Pick your battles, buuut...

and what kind of satisfaction you'd get out of it

Sometimes, that becomes the (rewarding) challenge, all in itself.

[eccerr0r]

Re: Can these speakers be repaired?

also make sure you have enough slack so that the wire doesn't rip out the paper cone when the amplifier is turned up to 11 ... but that probably is why they got blown in the first place.

[petehall347]

Re: Can these speakers be repaired?

at a pinch new solder wick will work for tinsel wire ..if all else fails fit some G12 speakers .

[tibimakai]

Re: Can these speakers be repaired?

Yes, just replace the tinsel wire, found some on Ebay. I did this on a 10" Klipsch subwoofer.

[jiroy]

Re: Can these speakers be repaired?

When your solder tip isn't working well , buy some Lemon salt (very cheap) , and dip the tip head into it , in a cup . You can also mix it with Glycerine for a practical mold ..
Don't tell anyone I told you so ..lol ..

[Keshenatech1]

Re: Can these speakers be repaired?

I found a pair of 12" 70W guitar amp speakers on Amazon Prime for only $45. Thought that would be more cost efficient for the customer than the hours I'd spend trying to re-lead the old ones. But just one problem, they don't quite fit. Same diameter, same number of mounting holes. but won't quite fit over the 4 studs. The holes in the original speakers are larger and more oblong than the smaller round holes in the new ones. Should I attempt to file or drill them out bigger, or send them back while I still can?

[petehall347]

Re: Can these speakers be repaired?

use a round file . drilling will prove difficult unless you have a spot weld drill bit . even then it would be hit and miss lining it up .

[Keshenatech1]

Re: Can these speakers be repaired?

Thanks for the suggestion. Borrowed a round file from my tool box at work for the weekend and minimal filing I got them to fit and install. Most of the issue was just the thick gasket material covering most of the inside edges of the holes so once I got that out of the way I only had to do a little metal filing in a couple spots.
Now I have one further question. I'm not sure if I should continue here or start a new thread. But my original speakers as you can see in the picture are labeled 8-16 ohms. I've never seen that before. Usually a 4, 8, or 16 but not a varying range like that. My new speakers are rated at 8 ohms each so in parallel it's putting 4 ohms load on the amp. It sounds great but after about 1/2 hour of playing, it got very warm near the output transistors. If the original speakers were close to 16 ohms, I'm wondering if I should wire the new ones in series for less load on the amp. It's a 70's vintage Kustom brand model 11-L guitar amp, and I can't find any specs or documentation on it online, or have any idea if it's "normal" for those to run hot. What do you guys think?

[Keshenatech1]

Re: Can these speakers be repaired?

Update: I rewired it putting the 2 speakers in series and it still runs hot. Still sounds good too. I'm going to leave it because the static resistance of the old speakers (alligator clip leads on what's left of the lead wire) measure around 12 ohms and my new ones with the 8 ohm impedance rating measure just over 6. So I figure it's better to go a little high than too low and overload the amp. Hopefully the running hot is normal and that nothing burns out. I did read somewhere that these old amps are biased high but haven't had much experience working on them.

[momaka]

Re: Can these speakers be repaired?

Or hits the basket and shorts the amp!

Happened to Garret Claridge in one of his videos trying to blow up a pair of 8" Cerwin Vega woofers.
This one, actually:
https://www.youtube.com/watch?v=sK7CO9KOgqU

So I figure it's better to go a little high than too low and overload the amp.

+1

[alfatv]

Re: Can these speakers be repaired?

Turn off the volume, then
- Check if it's still running hot
- Measure DC voltage across the speakers