KLH 22 crossover

punchback

punchback

Active Member
Did KLH use a combo capacitor in its crossovers? I found this cap inside the speaker. I'm assuming, based on the silkscreen on the cap, red is common, bare is a 8uf, and blue is a 16uf. When I measured with my multimeter red to bare was 16.75 uf and red to blue was 26.53 uf. Measurement made out of circuit. Could this be why both tweeters are burned out?
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KLH speakers often have dual caps in them, and they were all pretty crappy. Your drawing makes perfect sense. Just acquire a couple of 16's and 8's and you will be all set to go.

Have you tried applying a signal directly to the tweeters to make sure they are really "burned out"? If they are, the out of spec 8uf caps could have contributed to their demise.

Roy
 
I had 22's that I recapped then gifted to a friend. Very nice sounding speakers especially for a small speaker. If I recall correctly I did have a dead tweeter that came back to life after the recap. Probably worth resealing the cloth surrounds with the Vintage-AR product on ebay while your at it. Well worth the expenditure as resealing the surrounds will bring the bass back. The cloth surrounds I'm sure has become porous over the decades as the original sealer wears off. When the surrounds are porous the cabinet is no longer "air tight" which is essential for any acoustic suspension speaker to be at its best.
I think the 22's are some of the best "large" sounding speakers from a small enclosure that I have ever heard. Good luck in bringing them back to their former glory!
 
As RoyC said, the KLH have those dual caps in them.

I have a pair of KLH 20 and KLH 17s opened up right now for recap.

Both tweeters in the 20s were dead when I hooked the speakers up to a receiver.
Hooked tweeters up to my DMM and both registered ~4.2 Ohms

KLH 20s - 2+2uF and 2+4uF dual caps

KLH 17s - 8uF and 2+2uF dual cap

+1 on the re-doping of the cloth surrounds.

Enjoy - lots of help available on AK for KLH restoration.
Mike
 
I'll try to attach the tweeters directly and see. I don't hold out hope since they were 0 ohms on the dvm.

I have some of the surround sealer from Vintage -AR and the surrounds will be sealed shortly.
Thanks for the feedback.
Alan

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Assuming the tweeters are dead... I've been looking on fleeBay for vintage replacements but no luck. No 22 or 24 tweeters have been there for a while. If I decide to replace with new is that phenolic tweeter sold by Parts Express a pretty close replacement tweeter?

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punchback said:
Assuming the tweeters are dead... I've been looking on fleeBay for vintage replacements but no luck. No 22 or 24 tweeters have been there for a while. If I decide to replace with new is that phenolic tweeter sold by Parts Express a pretty close replacement tweeter?

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Click to expand...

punchback,

I believe I have two original tweeters in excellent condition. Send me a PM if interested.

Roy
 
I'm a newbie to recapping/speaker restoration & would be very grateful for any advice here.
I happily picked up a pair of KLH 22s (1967 stamp date) recently but they seem to have crossover issues- one unit being slightly quieter overall with more midrange in the woofer (listening test w/ speakers side by side, switching speaker wire leads. Definitely in the speakers).
I have a multimeter but am not sure what/how to test.
Pics of the caps below- not quite what punchback found.
It's safe to assume these caps have drifted, right?
I would be very grateful for good replacement recommendations.
Also, any opinions on sealing the dust caps when resealing surrounds?
Thanks for any help!
IMG_0761.JPG IMG_0763.PNG
 
PICT0078.JPG

I believe the 22 and 24 have the same crossover. Here is my replacement for the 24.
 
Looks like a Boto has the same cap I had on the other hand you have a 4uf single. I used the poly caps from Parts Express.
 
You need a DMM that can read capacitance. One end of the capacitor should be removed from the circuit if you are going to test it.

As many of the older caps age, their values actually can go up. The bad news is the when the value goes up, the cross-over point drops which can put a tweeter in the danger zone of hitting its resonance frequency (which will allow too low of a frequency into it. This will blow up the tweeter if too much power is applied.
 
thirelian said:
I'm a newbie to recapping/speaker restoration & would be very grateful for any advice here.
I happily picked up a pair of KLH 22s (1967 stamp date) recently but they seem to have crossover issues- one unit being slightly quieter overall with more midrange in the woofer (listening test w/ speakers side by side, switching speaker wire leads. Definitely in the speakers).
I have a multimeter but am not sure what/how to test.
Pics of the caps below- not quite what punchback found.
It's safe to assume these caps have drifted, right?
I would be very grateful for good replacement recommendations.
Also, any opinions on sealing the dust caps when resealing surrounds?
Thanks for any help!
Click to expand...

You've got the original Model 22's, which used a single 4uf capacitor on the tweeter in a "first order" crossover.
The rest of this thread actually concerns the later Model 22A....which used 16uf and 8uf caps in a more complicated "second order" crossover.

Don't let this confuse you.
Chances are all you need to do is replace the 4uf caps in your speaker with these:
https://www.parts-express.com/dayton-audio-dmpc-40-40uf-250v-polypropylene-capacitor--027-421
 
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Actually, here's a schematic of the original Model 22 crossover. Don't remember where it came from. Possibly an older thread on this site?model 22 crossover.jpg
 
Thanks everyone for the good infos!
Thanks 45rpmspinner for the link. I had looked at that cap but am a bit confused because the caps in my speakers are labeled 50V, not 250V.
Also, is the M24 pictured another cap? Any idea what a good replacement would be?
WaynerN, I have a DMM & will test. Weirdly, to my ear I'm not hearing too much low end coming out of the tweeters but am hearing more mids out of one of the woofers- that is unless I miss identified the source of the mids.

I'm looking forward to getting on this asap.
 
thirelian said:
the caps in my speakers are labeled 50V, not 250V.
Click to expand...

A higher voltage rating doesn't matter.
I'm not sure what your question about the Model 24 is about.
As far as I know [and certainly looks that way from the pic] Model 24's have the same crossover as the Model 22A....not your Model 22's.
 
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thirelian said:
I'm not hearing too much low end coming out of the tweeters but am hearing more mids out of one of the woofers
Click to expand...

Out of spec capacitors can throw the crossover point out of whack....and thus make the speaker sound unbalanced.
 
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Another thing that happens with old caps is that the resistance increases (ESR, equivalent series resistance) and ESR is also frequency-dependent. So a cap may even measure fairly close to nominal capacitance but signal is being lost due to ESR.

A speaker this old with those caps, I'd recap without even giving it a second thought. Some folks don't, but for this speaker the cost for good caps is pretty low, and if you already know the speaker has low volume problems, recapping is a presumptive remedy.
 
Ok good to know about voltage & ESR. 45rpmspinner, ha I was actually asking about that 2nd cylindrical object wired up to the original 4uf-50v cap in my pic above, mysteriously labeled M 24... I haven't been able to figure out what it is just yet, though I gather from your first reply in this thread that you don't think it's an issue...

Thanks again all- this info is really helpful.
 
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