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how to diagnose speaker problems KLH model 5

Guest hangten

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Guest hangten

I just picked up a tired looking pair of KLH model 5's for $30. They sound great except that one speaker has no sound coming from the tweeter or the woofer. I've done a lot of reading on this forum, but am still in the dark about how to go about figuring out where the problem lies, and also what problems might exist besides blown speakers, crossover caps needing replacement, loose connection, etc...

A friend who is into vintage audio suggested spraying deoxit into the knobs on the back for starters.

I have opened up the speaker - there do not appear to be any loose or broken connections.

any suggestions (or links to outside sources) on how to diagnose/isolate speaker probs would be greatly appreciated.

I have had some limited experience with electronics (Heathkits as a kid, modifying electric guitars as an adult), but am currently quite rusty...


Aram Stith

and by the way, when I hooked these speaker up to try them out, they really sounded great - very detailed. I happened to have a 45 year old copy of some Bach concertos on the turntable, so I just put that on....Amazing!!, even with one of the speakers not functioning properly - very exciting!

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Your post indicates you have opened up the problematic speaker. You wrote the woofer doesn't work. Can you temporarily hook up your speaker wires to the back of the woofer terminal? Or, you can also test the voice coil for damage by attaching wires from each connector to the sides of a C or D size battery. The cone should move either in or out if the VC is still alive.

To test the problem tweeter, you can again, touch your speaker wires to the two terminals that have wires leading to the tweeters. If I recall correctly, the tweeter pos is yellow and the neg is black. WARNING! do this ONLY on low volume with high frequency music playing so as not to damage the tweeter.

Trying to clean the switches is a good idea. However, I have found these switches don't deterioriate like some other vintage ones.

I suggest you change the tweeter capacitors at a minimum on both speakers. You can download the KHL5 schematic and parts layouts from the library here and follow the circuit in your crossovers. Many of the 5 xovers were fitted with Callins caps. They are black with red ends. They are not very good and were the cause of many suspected tweeter failures in KLH 6's.

Good luck.

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I agree with Carl--replace those caps. Also be sure to inspect the resistors for signs of burning--you may need to replace those, too.

The following thread contains some praise for Carl's Model Five rebuild, photos of his re-caps using Solens and some more exotic Polk speaker cap replacements. Also some photos of my recap job using Dayton caps and Mills resistors, and a re-cap I did for fellow CSP member Rob, using HUGE Clarity Caps:


Here is a Five with Clarity Caps:


Good luck


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Guest hangten

Sunday afternoon

I opened up the speakers - took out the tweeter, hooked my stereo spkr wire up to it and it worked!

unforutnately I got nothing out of the woofer.

So from this I assume that

1. the tweeter problem is due to degraded caps (all other connections look good by eye)

2. the woofer problem is a blown woofer - - are there other tests I can do -maybe I should just try the D cell battery to be sure as Carl suggested above.

If the assumptions above are correct, I'm going to order some capacitors and scrounge around for a new woofer on Ebay unless anyone has a better suggestion...



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Hi Aram

Definitely try the battery, but it sounds pretty bleak ;)

Suggest you check this thread for woofer replacement compatibility:


also--try posting under the for sale/wanted section of this forum. You may find a member who has one woofer to sell.

Good luck!


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