KLH Model 6 possible dead tweeter?

[Joolian]

I recently picked up a pair of KLH Model 6s (screwed woofer, not glued) and found that the tweeter in one of them sounded a bit weak. I tried flipping the channels from my amp to check if that was the issue but it persisted in the same speaker, and after a recap today it's still the same. The tweeter does produce sound, but it sounds 'airy' for lack of a better word, and a bit lacking in power and midrange. Does this seem like a tweeter on its way out or possibly just a resistor? I'm quite new to working on audio equipment so apologies if it's an obvious answer.
EDIT: After doing a bit of research I've realized I made a mistake during the recap - the original 2uF capacitor in there is apparently a parallel cap (hence the two leads coming out of one end and why I have two leftover 2uF caps...). I don't believe this is causing the issue because the one tweeter is fine but I'll have to get back in there and fix this up at some point. Rookie mistake!

Thanks

 

[Dswankey]

I recently picked up a pair of KLH Model 6s and found that the tweeter in one of them sounded a bit weak....after a recap today it's still the same .... Does this seem like a tweeter on its way out or possibly just a resistor? I'm quite new to working on audio equipment...

KLH 6 Speakers are one of the most discussed & documented speakers here on AK and have been for quite awhile.

I think it would be fair to say that a vast majority of the time it's usually not the tweeter.

Be patient as someone will be along shortly to share their knowledge, suggestions etc

 

[RTally]

It sounds like it may be the tweeter, but there is a way to tell definitively. Swap the tweeters between cabinets. If the weak sound follows the tweeter, then the tweeter is bad. If the bad sound stays with the cabinet, then there is a crossover problem.

Tweeters from KLH Model 6, 17, 20, and 30 are interchangeable.

 

[Joolian]

It sounds like it may be the tweeter, but there is a way to tell definitively. Swap the tweeters between cabinets. If the weak sound follows the tweeter, then the tweeter is bad. If the bad sound stays with the cabinet, then there is a crossover problem.

Tweeters from KLH Model 6, 17, 20, and 30 are interchangeable.

I will definitely give that a go in the next couple days along with soldering in the parallel caps I forgot!

 

[RTally]

I will definitely give that a go in the next couple days along with soldering in the parallel caps I forgot!

Wait. You did not replace all the caps when you recapped? The most common failure mode for KLH tweeters is a failed cap. All the caps need to be replaced. I would finish the recap before swapping the tweeters.

Also, do you notice a change in sound when you operate the switch on the back?

 

[Dswankey]

^

EDIT: ...I've realized I made a mistake during the recap - the original 2uF capacitor in there is apparently a parallel cap (hence the two leads coming out of one end and why I have two leftover 2uF caps...). I don't believe this is causing the issue because the one tweeter is fine but I'll have to get back in there and fix this up at some point.

Let us know what happens also if you don't already have this it's the OEM crossover diagram

 

[Joolian]

Wait. You did not replace all the caps when you recapped? The most common failure mode for KLH tweeters is a failed cap. All the caps need to be replaced. I would finish the recap before swapping the tweeters.

Also, do you notice a change in sound when you operate the switch on the back?

I’ve just gone in and fixed the caps. This fixed the switches on the back which didn’t do anything before, although the one tweeter still sounds fuzzy and distant. Gonna swap them right now and see what happens.

 

[Dswankey]

Looking forward to the outcome

 

[Joolian]

Slightly unexpected outcome - I swapped the tweeters and to my ears there now seems to be no difference between them. When I pulled the “bad” tweeter out the wire nut holding the ground cables together basically slipped right off and none of the wires were really coiled together well. This is really the only answer I can think of because nothing else changed. I’m calling it good before I go mad tilting my head between speakers!

 

[wiredbecker]

Classic. Check out this DIY video I found yesterday.

It's worth clicking through to the content. I'll be incorporating these steps going foward.

I had no idea that you should keep twisting the wire but to continue creating a good mechanical connection. An alternative solution is to pre-twist the wires before using a wire nut or use a wago connector. I'm glad you found a cheap solution to your tweeter issue.

 

[Joolian]

Classic. Check out this DIY video I found yesterday.

It's worth clicking through to the content. I'll be incorporating these steps going foward.

I had no idea that you should keep twisting the wire but to continue creating a good mechanical connection. An alternative solution is to pre-twist the wires before using a wire nut or use a wago connector. I'm glad you found a cheap solution to your tweeter issue.

This was a helpful watch. I did pre-twist the wires (although only the exposed part going into the wire nut) but to be completely honest the wire nuts that are presumably there from the factory aren't exactly confidence inspiring. It's nothing I'm gonna go in and change anytime soon but if one were to work on a pair of these I'd suggest getting new wire/lever nuts if you're already gonna be in there.

 

[wiredbecker]

Right? I was so surprised to see wire nuts inside my KLH 17s when I opened them up!