KLH Model 5 Troubleshoot - Noisy Tweeter

[bornonatrain]

Good afternoon.

I've had these KLH Model 5s for about 4 years ago. Purchased on Craigslist from someone in Southern Brooklyn. He said his friend had redone the crossovers recently. He was Russian and I assumed his friend did a good job because South Brooklyn Russians seem to know their analog audio. The seller did not seem to be that happy with them, and I suspected it was just that they needed a good seal, which I addressed. They sounded pretty good to me after that.

Fast forward 4 years and I've noticed some distortion on my left Model 5. I've identified that it is coming from the tweeter, and i've tested that it is not an amp issue by swapping the speakers. A month or so ago I had an accidental burst of sound when I turned on the amp (audio source accidentally running) at high volume...

What is my next step for troubleshooting? Attached is a picture(s) of the crossover of the speaker with the troubled tweeter. Is their anything obviously / visibly wrong with the crossover? If not, how should I test it? My gut says I should try the tweeter in my right Model 5 to rule out a crossover issue, but I'm still wondering if the crossover may have been rebuilt incorrectly. Have not opened the other speaker as of yet.

For context I'm using a newish Yamaha A-S701 (my Sansui AU-417 is out of commission until I can get to restoring it [newbie], but the issue was present on that amp as well). I've swapped speaker wires, used 2 separate DACs, a CD player, and swapped composite audio cables.

The distortion is most present with dialogue and piano. I actually hardly notice it otherwise. When I listen closely to the tweeter, it's faint, but it's a crackly distorted sound. Thinking maybe that would suggest an issue on the crossover?

 

[swechsler]

First thing I'd try is to Deoxit the controls. But if you don't have Deoxit, swap the tweeters first.

Actually, you can check by rotating the controls a bunch of time with the speakers playing, which should temporarily get rid of any oxidation. If it makes the sound better, then oxidation is your problem.

 

[Dswankey]

.. My gut says I should try the tweeter in my right Model 5 to rule out a crossover issue,..

Trust your gut, plus it's a good form of process of elimination

 

[bornonatrain]

First thing I'd try is to Deoxit the controls. But if you don't have Deoxit, swap the tweeters first.

Actually, you can check by rotating the controls a bunch of time with the speakers playing, which should temporarily get rid of any oxidation. If it makes the sound better, then oxidation is your problem.

The control pots on the crossover? It didn't actually occur to me that the speaker controls could pose an issue. I gave them a good spray and worked on the knobs a bit, no change so far.

 

[swechsler]

The control pots on the crossover? It didn't actually occur to me that the speaker controls could pose an issue. I gave them a good spray and worked on the knobs a bit, no change so far.

They definitely can cause an issue, but you've most likely ruled them out. Let us know how the tweeter swap works out.

 

[bornonatrain]

@swechsler @Dswankey thank you for the help so far. I did the swap, and the issue follows with the tweeter. to be extra double triple certain of things i put the good tweeter on the other crossover and it continued to sound good.

Is the tweeter repairable or is it just dead?

 

[swechsler]

Probably not repairable, but I'd pry off the tweeter grille and see if there is any damage to the cone.

 

[Dswankey]

I know nothing about repairing a tweeter let alone what that would entail and if it's worth the time or effort

Whatever you decide the good thing is if I'm not mistaken is the tweeters from the Model 12 & 23 would work in addition to another 5

 

[bornonatrain]

I know nothing about repairing a tweeter let alone what that would entail and if it's worth the time or effort

Whatever you decide the good thing is if I'm not mistaken is the tweeters from the Model 12 & 23 would work in addition to another 5

Appreciate it. I'll start looking for a new tweeter...

 

[GD70]

That amp spike probably did the damage. I’d replace it and be done.